FAUNA (ZOOLOGY) :

Assam along with its North Eastern parts of India is of exceptional biogeographical interest not only to India but to the world today. it is from this region that the obliteration of the Pre-Tertiary Tethis Sea began producing in its wake a land connection between the Indian Peninsula and the main Asiatic mass to its north.

The Assam region then onwards served as a great faunal Homeland and a gateway,through which the indo-Chinese elements of the Oriental Fauna and also that of Palaeoretic could spread to India and colonize the country. In fact,the history of the post-Tertiary faunal dispersal in India is peculiar,in as much as all the faunal invasions have come through two great faunal gateways,the first one in the Assam region and the second one in the Northwest. This was because of the emergence of the rising Himalayas as a great barrier wall concomitant with the obliteration of the Tethis Sea so that except for the montane species,the faunal dispersal had to take place through either of those Faunal Passes. Of them,the importance of the Northwest gateway dwindled after the disappearance of the Siwalik Fauna in the early Pleistocene and the changes in the physiography of the Indo-Gangetic trough,of which the formation of the Thar of Rajputana Desert was the major event,constituting barriers to the dispersal and the recolonization from the Northwest. As a result we see that most of the Faunal dispersal and the recolonization in the recent period have taken place through the Gate-way of Assam,due to which the Indo-Chinese Faunal elements constituted the most dominant entity in the Fauna of India in general and the fauna of Assam in particular.

Now, however, when we are speaking of the recent times, there is on the contrary, a geological and climatic discontinuity between Assam and the rest of the States of India, except only the region of similar climate and biotope in the Western Ghats. The discontinuity,that is readily vissible at the region of Garo-Rajmahal Gap by distinctive dispersal breaks acts as a Filter-Barrier in the effective dispersal of Assam Fauna Complex either way.

Thus today, Assam stands as the western-most boundary of the range of many Peninsular species such as the Spotted Deer and the Mulbery Silkworm. Primarily therefore, the Fauna of Assam are the Indo-Chinese Complex rather than Peninsular Indian Complex. Even though with the variatable admixture of the Peninsular and the Ethiopian elements, the Palaeoretic Monatane elements also found intruded into it, making it more richer than elsewhere in India. However,many of the relict species of the Southern Peninsular India,mostly confined to the Western-Ghats, have closely related species only found in Assam,even though separated by a gap over one thousands five hundred kilometres.

Assam eco-habitat thus hold and important pivotal biohabitat in the historic process of the progressive evolution of the present day Flora and Fauna of India,serving as Homeland and effective Gate-way to floristic-faunal influx. The analytical study of the Vertebrate/Invertebrate fauna even though so far very badly neglected,but for eco-biologists it is most essential for a clear comprehension of the derivation, composition, distribution, origin and their present day status,etc.,of the Assam and to that matter the Indian Vertebrate and Invertebrate Faunal complex and their association with forest complex.

Vertebrate Fauna Complex of Assam : The vertebrate fauna of Assam is the richest and most diversified among the comparable habitat regions in India. Because Assam is favoured with a subtropical, mesothermal climate with copious rainfall that sustains a Biotope eminently suitable for the Indo-Chinese and Indo-Malayan fauna that occupies it. Its tropical and sub-tropical moist evergreen and semi deciduous forests enure the best survival of Mammals,Birds,Reptiles Amphibians,Fishes and Arthropods along with other invertebrates enhancing the pace of their specification by affording varied ecological riches than would have been possible in the dry and semi dry deciduous forest habitats and the plains of the rest of India, excepting to a greater extent the Western Ghats.

THE MAMMALS : Out of the total of one hundred and thirtyfive known genera of land Mammals of India,about eightyfive genera (63%)are represented in Assam. Out of the eleven orders, the Carnivora are the richest in genera. Followed by Rodentia and Chiroptera.

In the member of species and subspecies the Rodentia of Assam ranks the highest. But among the families. Muridae,Viverridae and Vespertilionidae are very well represented. However,the number of genera of Viverridae in Assam is more than in the rest of India.

Table 1: Mammalian Fauna of Assam

  Order/Family        Genera         Species            Subspecies
    Insectivora
    Tupaidae                      1                    1                       3
    Talpidae                        1                    1                       2
    Soricidae                      4                    7                       10
        Chiroptera
    Pteropidae                     2                    3                      3
    Megadermatidae            1                    2                      2
    Rhinolophidae                3                    17                    18
    Vespartilionidae             9                    19                     22
    
    Order/Family            Genera            Species            Sub-species    
    Primates Lorisidae         1                      1                       1
    Cercopithecidae             2                      5                       8
    Pongidae                        1                      1                       1
    Pholidota
    Manidae                         1                      1                        1
           Carnivora
    Canidae                          3                      3                       3    
    Ursidae                          3                       3                       3
    Mustelidae                      6                      7                        7
    Viverridae                      8                      10                     13
    Felidae                           3                       8                        8
    Proboscidea
    Elephantidae                  1                      1                         1         
    Perinsodactyla
    Rhinocerotidae              1                       1                         1
    Artiodactyla
    Suidae                           1                       1                         1
    Cervidae                        4                       6                         6
    Bovidae                         5                       5                         5
    Lagomorpha
    Lerporide                       2                       2                         2
    Ochotonidae                  1                       1                         1
             Rodentia
    Sciuridae                        6                      12                      18
    Hystricidae                     2                       2                         3
    Rhizomyidae                   2                       2                         2
    Muridae                          11                     25                       36
    Cetacea
    Platanistidae                    1                       1                          1
    Total (not exhaustive)        86                148                    186

The sixteen genera of mammals,for which Assam and a small west-ward Himalayan strip extending into Nepal through Bhutan form the southern boundary of their present habitat range. But at present they are totally absent from the earlier habitat,the Peninsular India and they are as below :

 

    Order                                              Family                                   Genus
    Insectivora                                     1.Tupaiidae                        I. Tupaia
                                                           2.Soricidae                       ii. Anourosorex
    Primates                                         3.Lorisidae                       iii.Nyeticebus
                                                           4.Pongidae                      iv.Hylobates
    Carnivora                                       5. Viverridae                    v.Arctictis
                                                                                                  vi.Aretogalida
    Prissodactyla                                 6.Rhinocerotidae            vii.Rhinoceros
    Artiodactyla                                   7.Bovidae                         viii.Budorcas
    Rodentia                                        8.Hystricidae                    ix.Atherurus
                                                          9.Rhizomijidae                   x.Rhizomys
                                                                                                   xi.Cannomys
                                                        10.Muridae                          xii.Chiropodomys
                                                                                                   xiii.Micromys
                                                                                                   xiv.Hadromys
                                                                                                   xv.Eothenmys
                                                                                                   xvi.Dacnomys
     Total =order 6                               Family 10                Genus  15        

 

Of the above 10 families,the Pongidae and Rhizomyidae are practically confined to Assam,Chittagong and the adjacent hilly tracts. But the mammalian families,which are also present elsewhere in India as mentioned below are known to be altogether absent from the Assam region.

              1.Erinaceidae                  6.Hyaenidae
             2. Rhinopomatidae           7.Equidae
             3. Embellonnridae            8.Tragnlidae
             4. Molossidae                  9.Muscardinidae
             5.Procyonidae

 

Because by and large the families are the general inhabitants of relatively drier habitats. Moreover,the study of their extralimital distribution showed that most probably they entered India through the North Western Route. These two factors can explain their probable absence in the modern times in Assam.

The order Chiroptera is conspicuous by the absence of a number of families and generation from Assam. Of the seven families of Bats occurring in India,four of them are not represented in Assam. The group Bovidae are likewise poorly represented as compared to the number of species occurring in the North-Western India.

However,it is true that,almost all the genera found in Assam are also present in the Indo-Chinese region, like Carpolagus (Lagomorpha) Golunda and Hadromys (Rodentia), Platonista (Cetacea), etc. Therefore, the dis junctive distribution in the central and Eastern Sub-Himalayan region and Assam has attracted considerable research attention.

Birds : During the late Pliocene period,due to the great changes and a wide variety of habitats unique flora and fauna of Assam came to be highly diversified into many beautiful and varied forms. Assam is characterised by Bhabar forest and Terai Formation and the Siwalik ranges. In the Bhabar tract the climate is comparatively dry and in the Terai region there are ample deposits of fine silt,the drainage is poor but the water table is quite high. The natural monsoon forest is found in this region. It was also possible that the avifauna of the Himalayan Mountain system might have migrated along the narrow passage ways form by the flood plains and gorges of the Brahmaputra river system,where there are altitudinal as well as east-west variations in this sub-region constituting the diversified home and playground of the avifauna. Although considerable depletion of forest cover has taken place,yet Sal(Shrea vobusta)was the dominant tree. The Terai of this region is characterised by tall grassy(elephant grass)meadows with the savannah vegetation making ideal ecosystem with lowlying beells and rivers and magnificent tall trees for inhabiting varied species of birds. The major families of Assam birds are

 

: (Not exhaustive):

Flying birds (Family)                                       Example

1.Podicipididae (Grebs)                                 Podiceps ruficollis

2.Pelicanidae (Pelicans)                                Pelecanns philippensis

3.Phalacrocoracidae (shag,

Comorants and Darter)                                  Phalacrocorax niger

4.Ardeidae (Herons,

Ergets,Bitterns)                                             Ardeola Grayii grayii

5.Ciconiidae (Stocks)                                    Ciconia episcopus

6.Threskiornithidae

(Ibis, Spoonbill) Plegadis faleinellus

7.Anatidae (Ducks,Geese, Swans)             Todorna ferruginea

8.Accipitridae ( Kite,

Hawks,Vultures )                                          Elanus caeruleus

9.Falconidae (falcons)                                  Falco chieqnera

10.Phasianidae (Pheasants,

Patridges,Quails)                                           Gallus gallus murghi

11.Gruidae (Cranes)                                     Grus nigricollis

12.Ralliedae (Rails,Coots)                             Gallicrex cinerea

13.Otididae (Bustards)                                  Ardeotis nigriceps

14.Jacanidae (Jacanas)                                Metopidius indicus

15.Charadriidae (Plovers,

Sandpipers,Snipe,woodcock, etc.)                Tringat totanus

16.Rostratulidae (Painted snipe)                     Rostratula benghalensis

17.Resnrvirostridae (Stilts)                             Himantopus himantopus

18.Laridae (Gulls,Terns)                                 Larus ridibundus

19.Pteroclididae (Sandgrouse)                      Pterocles exustus erlangeri

20.Columbidae (Pigeon,doves)                     Treron phoenicoptera

21.Psittacidae (Parrots)                                 Psittacula Krameri

22.Cuculidae (Cuckoos)                                 Cuculus micropterous

23.Otididae (Florican)                                    Eupodotis benghalensis

24.Strigidae (Owls)                                       Bubo bubo

25.Caprimulgidae (Night Jars)                        Caprimulgus indicus

26.Apodidae (Swifts)                                     Apus affinis

27.Alcedinidae (King fisher)                          Alcedo atthis

28.Meropidae (Bee eater)                              Merops orientalis

29.Coraciidae (Rollers)                                  Coracias benghalenpis

30.Upupidae (Hoopers)                                 Upupa epops

31.Bucerotidae (Horn bill)                             Tockus birostris

32.Capitonidae (Barbets)                               Megalaima zeylanica

33.Indicatoridae (Honey guides)                    Indicator Xanthonotus

34.Picidae (Woodpeckers)                              Dinopium Benghalensis

35.Pittidae (Pittas)                                           Pitta braelyura

36.Aluudidae (Larks)                                     Mirafra assamica

37.Hirudinidae (Swallows)                            Hirundo rustica

38.Oriolidae (Orioles)                                      Oriolus xanthornus

39.Pycnonotidae (Bulbuls)                            pycnonotus cafer

40.Dicruridae (Drongos)                                Dicrurus adsimilis

41.Sturnidae (Starlings)                                  Aeridotheres Fuscus

45.Corvidae (Jays,Magpies,Crows)             Dendrocitta vagabunda

46.Bombycillidae (Waxwing,

Hypocolius) Bombycilla garrulus

47.Campephagidae (Cuckoo,Minvets)          Coracina novaehollandiae

48.Irenidae (Fairy blue,Loras,

Leaf birds)                                                    Chloropsis cochinchinensis

49.Muscicapidae (Babblers,Fly

catchers, Warblers,Thrushes,

Chats)                                                             Copsychus sauaris

50.Paridae (Titmica) Parus major stupae

51.Sittidae (Nuthatches,

Creeper)                                                            Sitta castanea

52.Motacillidae (Pipets,Wagtails)                       Motacilla flava

53.Laniidae (Shrikes)                                       Lanius schach

54.Dicaeidae )(Flower peckers)                      Dicaeum agile

55.Nectariniidae (Sun Birds)                            Nectarinia asiatica

56.Zosteropidae (White eye)                         Zosterops palpebrosa

57.Ploceidae (House sparrows,

Weaver birds,Munias, Wax bills,

Avadavats)                                                      Passer domesticus

58.Firngillidae (Chaffinches,

Gold finches)                                                  Carduclis carduclis

Thus the habitat of Assam harbours the magnificent number if about 59 families,out of the 78 families of known birds of India. These 59 families contain denizens of about more than 300 species, some of which have been presented in the above table. However, in the comparative estimates, the hills, plains, beels and marshes of the flower reach of the Brahmaputra harbours the greater number of birds species of Assam, as it provides a mesothermal climate with abundant food resources to nearly all types of birds.

The National bird : Peacock (Pavo cristatus L. Neoruithes, Neognathe, Galliformis)-is a native bird of India and extends upto Nepal, Bangladesh and Sri Lanka. Peacocks are found in Assam in forests and plains,particularly in the lower reaches of Brahmaputra valley. The sexual diamorphism is prominent and the cock is found attaining a length of 1.8m including the 1.2m tail with a variation of + 0.15 to 0.25 m.A tuft of 24 + 2 bare shafted gold tipped feathers found on the occiput of the head. The hen is dull coloured without tail coverts. Head of the hen is chestnut brown and face mostly white, the breast is brownish black and green but in case of the cook the underpart is purplish and face mostly white. The food of Peacock are grain, seeds, insects,lizards and snakes etc. Resting is on high trees at night and it prefers to live near rivulets, rivers and streams.

The mail spread its tail in the form of a fan and dances when happy. It produces a loud harsh,screaming sound-May awe and short gasping shrieks Ka-ann,Ka-ann repeatedly for 6-8 times. The nesting season is from January to October and lays 3-5 glossy pale cream colour eggs. They move in groups but seasonally sexes separate.

The white Pea-fowls are considered to be a mutant variety of blue pea fowls.

The Burmese species of white pea fowls is Pavo muticus.

Hunting Birds:There are several types and species of hunting birds in Assam. The most famous are Vultures,King vulture-Sarcogyps Calvus,Bengal vultures-Gyps bengalensis,Scavenger vultures-Neophrom perenopterus. They live in groups,are carrion feeders and useful scavengers.

Besides vultures,other hunting birds are kites,hawks and falcons. Special mention of some of the species are-Lagger falcon-Falco biarmicus,Blackwinged Kite-Ellannus caeruleus, Pariah kite-Milvus migrans, Brahming kite- Haliacetus indicus, Pale Harrier-Circus macrourus, Hawk Eagle-Spizaetus cirrhatus, Fishing Eagle-Haliacetus leucoryplus, Serpent Eagle-Spilornis cheela, Tawry Eagle-Aquila rapax,Red handed Marlin-Falco chicquera, Kestrel-Falco tinnunculus,etc. They have several common characteristics but differ mainly in colour and size. Breeding season is from February to June. They build their nest or trees and lay 3-4 eggs at a time.

 

Game Birds :

Several varieties and species of birds are eaten as food in Assam, particularly by the new migrants. The Tribes,both hills and plains are fond of the birds meet of most species of hill and plain birds. The very common examples of game birds are Painted Sand grouse-Pterocles indicus, common and grouse-Plaerocle exustus, Partridge-Francolinus francolinus, Painted partridge- Francolinus pictus, Grey Quail-Coturnix coturnix, Mountain Quail-Ophrysia superculiosa, Jungle fowl-Gallus gallus, Graylag goose-Auser auser, Large whistling teal-Dendrocyqna bicolor, Buddy Shelduck-Tadorna ferruginea ch are also some of the game birds.

 

Special mention may be made of Barheaded geese, the Rajhans, described greatly in our ancient literature and as the vehicle of Saraswati, the godess of learning. Its quils were used for writing. It is found throughout winter. It is migratory bird,arrives in Assam by the month of October and departs by mid March.


Singing and talking birds :

The best singing bird is Grey winged Black bird Turus merula. It is a plain grey brown bird with a black cap and orange yellow ring round eyes, legs and bill. It is found in well wooded hills, in groves and jungles near towns and villages. The male has a lond melodious song with mimicked calls. Several other members of lark family fall in this category. The order example are Bush lark-Mirafra assamica, the eastern skylark-Alanda gulgnla. The other example is Shama-Copchycus malabaricus. It is more popular cage bird than in wild,being highly prized as a songster.

The best talker birds of Assam is Hill Myna-Grakula religiosa followed by jungle Myna-Acridotheres Fuscus. They are accomplised mimics and talkers. The other favourite talkers are Grey headed Myna-Sturnus malabaricus and Pied Myna-SturnusCentra.They are popularly known as cage birds as they can imitate and repeat a few words.

The other song birds are Koel-Edynamys scopacea. The call of male begin with a loud Kuoo and rises in scale with successive Kuoo. The other singing birds to add are Indian Cuckoo-Cuculas microptesus,Plaintive cuckoo-Cacomantis merculinus,

Coucal-Centropus sinesis,Brainfever bird-Cuculus varius which sing day and night during the breeding time.

Pheasants : The pheasants or game birds are colourful and many of them have brilliant metallic plumage. The entire sub-family Phasaninae is concentrated in Oriental region except Afropavo in Africa.

Pheasants are heavy bodied with well developed bills,powerful legs for pecking and scratching on the ground. They are known to mankind from very long time for their delicious meat. But due to extreme hunting and loss of habitat these birds are becoming endangered in recent times. They are diurnal in habit and feed on mosses, ferns, leaves, insects and occur in the North Eastern, Assam in particular are follows :

  1. Ithaginis cruentus,size 45 cm.Blood pheasant.

  2. Tragopan satyra,siza 60 cm.Satyr Trogopan

  3. Tragopan blythii siza 60 cm.Blyth's Trogopan

  4. Tragopan teniminkii siza 60 cm. Temmink's Trogopan

  5. Lophophorus impejanus siza 70 cm.Monal Pheasant

  6. Lophophorus sclateri siza 70 cm. Sclater's Pheasant

  7. Crossoptilon crossopyilon siza 72 cm. Elwe's Pheasant

  8. Syrmaticus humiae humiae siza 90 c.Baned-back Pheasant

  9. Polyplecfron bicalcaratum siza 60 cm. Peacock Pheasant

  10. Paro cristatus siza 122 cm. Indian peafowl.

Reptiles :

Testudines or the chelonians constitute the very ancient group of Reptiles with their lineage going back to 200 million years. Today they are found living in arid waterless wastelands,lakes,rivers and the oceans. Exceptionally in Assam they are found in wet areas of westlands,beels, marshes, swamps, ponds and rivers.

To our understanding,the usage of the words 'turtle' and 'tortoise' have given rise to some confusion to some people, although they are easily found differentiated with the total hardness or partly softness characteristics of the dome shell..But in fact all the members of the order may be aptly called 'turtles'.

The snakes of the order Reptiles are perhaps the most misunderstood creatures in the world today. There are many baseless myths and superstitions about them and misconceptions that surround snake bites make them dreaded creatures. There are in India and Assam, a good number of places where snakes are protected and worshiped regularly with public festivals.

In fact snake constitute the most successful group of all reptiles in India and Assam in particular. Ophilogy attracted the attention of naturalists since time immemorial as they are found associated with Gods and Godesses in the India Mythology. Assam with its diverse habitat and climatic conditions harbours a rich snake fauna. Out of the nearly 235 species that occur in India,just only about 50 species are venomouse,which live in habitats where human density is very low or no human habitation. Moreover, most of the vanomous snakes venom are not toxic enough to kill a man or domestic animal.

The group Lizards of the order Reptiles dominated the earth for nearly 150 million years and a few of them are widely distributed and diversified. Most of them are characterised by a short body with four well developed limbs, a short flat tongue and an external ear opening. The tongue of lizard is used as a sensory organ and also for lapping up the prey. No vanomous lizards occur in Assam or in India .

Turtle and Tortoises

The Indian chelonians are classified into five families :

1.Dermochelyidae-Leatherback sea turtles

2.Cheloniidae-Sea turtles

3.Emydidae-Fresh water tortoises

4.Testudinidae-land tortoises

5.Trionychidae-Mud and water turtles.

The first two species do not occur in Assam and its adjoining seven states. Of the family Emydidae,the Cyclemys dentata is the commonest hill stream tortoise of Assam. The other common species is Cyclemys mouhati that occur nearly in all the tributaries of Brahmaputra. Both the species are omnivorous.

However,it will be better to treat them systematically to understand their present status in the state of Assam,although very little research work has been done.

Emydidae-Fresh water tortoises :

Spotted pond turtle- Geoclemys hamiltoni : The species is quite rare in Assam and can be considered as endangered. They were abundant in the Brahmaputra river valley but now restricted to lower Assam region. They are carnivorous in habit. Another species of pond tortoise Heosemys was known to be dense forest pond dweller of the lower reach of the Brahmaputra river is becoming very rate now.

Brahminy River turtle- Hardella thurgi in habitants the Brahmaputra river system. It leads a sluggish,concealed existence in the river bottom and prefers plant materials as food.

The River turtle-kachuaga kchuaga of the Brahmaputra river system can be distinguished from its larger size and very smooth appearance. It is very agile and dive down at a slightest alarm.

The canal or beel tortoise-Betagur baska is occasionally found in slow-moving rivers and canals but abundantly found in beels.It is very timid herbivorous tortoise of Assam now becoming quite rare.

Land tortoise-Testudinidae : The true land tortoises are characterised by their clubshaped, short and broad feet with two phalanges and entirely webless.

Red-nosed tortoise-Indotenstudo elongata is an Indo-chinese form and occur in the hilly regions of Assam. Its shell is greenish yellow above and below and has power of withstanding oppressive heat.

The Asiatic tortoise-Indotestudo emys is a big size tortoise preferring to live in the hilly regions of Assam wherever there is a good supply of water. Due to its large size the movement is slow and gets easily persecuted.

Mud and fresh water turtle-Trionychidae : The characteristics of this group of turtle is that its proboscis and jaws are concealed by fleshy lips, flipper like limps, webbed digits with three claws.

The Softshell Turtle-Trionys gangeticus is the common mud turtle of the Brahmaputra river system profusely distributed into the beels and low lying wetland areas. It prefers large beel canals with muddy bottom,and are both harbivorous and carnivorous in habit.

Narrow Headed Softshell Turtle-Chitra indica :This species is confined to the sandy. section of the Brahmaputra river system. It is notorious and fierce in temper and tries to bite when handled. It is carnivorous and feeds mainly on fish, crash, molluses,etc.

Indian Flap-shell Turtle-Lissemys punctata :It is generally found in the main channels of the Brahmaputra and its tributaries and could be sen swimming in shallow water of running in thick vegetation of the river bunks. It burrows in the river and beel bottom during winter months when water recedes. It feeds on fish,fruit and vegetables grown in the char areas.

 

Crocodiles :

The general appearance of crocodile is too familiar to us. Because they are known from legends to folk-tales as an elongated, large tail powerful enough for swimming and a long nostril with long jaws and teeth on it. In Assam, however,the true crocodiles are not found belonging to the genus Crocodylus but the Gharial belonging to the genus Gavialis found in the Brahmaputra river system.

The Gigantic Gharial-Gavialis gangeticus :It is only surviving species of the ancient Crocodile family. It was found swarm in the Brahmaputra,the Ganges,the Chambal and the Mahanadi river system including their tributaries. But at present its population has severally dwindled due to slaughtering for skin. Now hardly less than 200 individuals are surviving in those four big River systems. Gharial of India is listed as the most endangered species of wild life.

 

Lizards :

About kinds of lizards belonging to 8 families are known to inhabit India. Out of them Assam represents quite a good number. It will be convenient to deal with them here systematically.

Gekkonidae-Geekos :

These are small gentle lizards characterised by soft dull skin and clinging pads on their feet. They are found in house,on ground,in forests and trees. Geekos are the first among lizards/reptiles to have developed a true voice, rivalling the croaking of Toads and chirping of birds. They lay eggs and feed on insect. Of them the Assam species are :

House Geekos :

Wall lizards :Hemidactilus brooki

Smooth House lizard :H.frenatus

Tree Greeko :H.leshehenanlsti :The species enters also house sometimes.

Giant House lizard :Gekko geoko or 'Tokay'

Forest Geekos :Golden Hill Greeko-Calodactylodes oureus

Agamidae -Agamas :

Agamids are large group of lizards adopted to a diversified life in trees,on the grounds and in rocks. Majority are insectivorous but a few are herbivorous. They lay eggs and are known in India by about 13 genera. Some of them are found in Assam.

Rock lizards :

The Himalayan Rock lizard-Agama tuberculata :It is a gorgeously coloured lizard with shoulder,breast and flank turning bright yellow. It feeds on ants and butterflies.

The small rock lizard-Psammophilus blanfordamus :It is smaller in size, less versatile in colour and enter out houses.

Garden lizards :

The garden lizards are characterised by their compressed body,dorsal crests, long tapering tail and the throat fan.

The Indian lizard for Blood sucker-Calotes versicolor: It is brown body and it turns it throat, sides of the head and neck into searlet.

Small Indian lizard-Sitana Ponticeriana: It is a fast runner and the male brings its throat fan into play during courtship.

The Himalayan lizard- salea sp. (assamensis): They are found in the hedges, bushes and in the tea plantations. They are beautiful lizards when the male gular pouches assume the brilliant yellow hue.

The Flying Dragon- Draco norvilli :The patagia are beautifully coloured. These are free dwellers and seldom come to the ground. Their favourite food is the tree ants.

Mountain agamid :

The east Himalayan species- Japalura tricarinata is a terrestrial lizard found in the mountainous region of the State. It is pale-brownish dorsaly in colour.

Chameleon-Chamaeleonidae :

The Chameleon is strikingly different, pronounced by a high body, a springlike tail, a helmet-like knob at the nape and round bulging eyes. A chameleon can shoot out its club – shaped tongue to catch insects,its main food. Chameleon can change colour from green and brown to yellow, white and black and in different ways on both sides of the body so much so that it is impossible to tell the colour precisely. The only species so far known from Assam is the Indian chameleon – Chamaeleons Zeylanious that appear in wooded areas and tea gardens.

Skinks Scincidae :

Skinks are burrowing or ground dwelling lizards recognised by their overlapping smooth and shiny scales, a broad flat tongue and movable eyes. Majority of the skinks lay eggs, only a few bring forth their young ones. They are primarily insectivorous, although a few feed upon plant matter during adulthood. The so far known 25 species of Assam are as follows:

1. Mabuya dissimilis

2. M. inotata

3. M. macularia

4. M. carinata

5. M. multifasciata

6. M. tytleri

7. M. rugifera

8. M. quadricarinata

9. M. beddomii

10. M. trivittata

11. Dasia Subcaerulea

12. Spheno morphusindicum

13. S. dussumieri

14. S. Himalayanum

15. S. Ladaceuse

16. S. Macrotis

17. S. Beddomei

18. S. Laterimaculata

19. Ablepharus grayanus

20. Riopa albopunctata

21. R. punctata

22. R. Lineata

23. Chalcides pentadactylus

24. Barkudia insularis

25. Sepsophis punotatus.

Worm Lizards- Dibamidae :

The glassy sealed Indian worm lizard found in Assam is Dibamus novae. This burrowing lizard to a layman,with its vermifarm body and tiny concealed eyes under the skin appears like a slender snake. It is devoid of limbs, head is blunt and conical like worms.

Lacertids-Lacertidae :

The lacertids are wide spread typical lizards because of the slender bodies, well developed legs and long pointed tails. They preferably dwell in sandy grassy and rocky areas, shed their tail which is regrown. Majority are insectivorous although a few practise cannibalism. The following species of lacertids are known to occur in the geographical boundary of Assam.

1.Trakidromus sexylineatus khasiensis

2.Cabrita leschenaulti

3.C jerdoni

4.Ophisops jerdoni

5.O. Beddomei

6.O.microlepis

7.Eremias guttulata

8.E.brevirostis

Glass snake-Anguidae

The glass snake lizard- Ophisaurus gracilics posses a snake like head and very graceful in its movements. This lizards in found only in Assam hills, Khasi hills and Darjeeling in India. Despite all its traits like a snake, it is very mild creature, hide under logs and stones during the day and as darkness sets it feeds on insects.

Monitor lizard :Varanidae

Monitor is the largest of the living lizards. It has an elongated mobile head and unusually long neck and tail,snake like forked tongue. All monitors are scavengers or predators and they shallow their food unlike other lizards. Of the four kinds of monitors, three are living in Assam. The Indian monitor—Varanus bengalensis is the commonest of them and it is made with in the remote forest and outskirts of Assam villages. The water monitor-Varanus salvator is the second largest living lizard of the world and next to Komodo Dragon of Indonesia. Adults are dark with yellow sports and climb the trees for food. The yellow Monitor: Varanus flavesceus is very common. Its colouration is seen at its best during the monsoon with red-cross band but it fades by the retreating monsoon.

Snakes : Snakes live in a variety of habitat like human dwellings, old building, marshy lands, beels, rivers, agricultural areas, forests and mountains. No snakes except the blind snakes,boas and pythons have any trace of legs. They have no movable eyelids, lack external ear opening and hence can not hear normal way,but their capable of picking up earth-borne vibrations by their sensitive bodies. The tongue is deeply forked and its function is to probe the senses of taste, smell and touch. Majority of the Assam snakes are egg layers although a few can produce young ones. Assam snakes vary in size from >10 cm.to 6 m in length-in python.

The snake fauna of Assam comprises the following families.

1.Typhlopidae :Blind snakes :

There are small, worm-like snakes with smooth, shiny scales, hiding under logs, humus and even in the flower pots. About 14 kinds of them are found in India. Some of the Assam species are:

Brahminy blind snake : Ramphotyphlops braminus :It is reddish brown and black in colour, growing up to 17 cm.

Indo-Chinese blind snake :Typhlops diardi :It is larger than brahmini, growing upto 43 cm. brown above and paler below in colour.

2.Uropeltidae:Roughtails.The only species known from Assam so far is the Ocellate roughtail- Uropeltis ocellatus recognised by the oceli on its back,the tail is orange yellow ending in rugose shield with spicules.

3.Boidae:Pythons: Pythons are primitive snakes, have a stout body and short tail. There are two kinds of boas and pythons each in India. The Assam species are :

India Red boa-Eryx johni :About 96 cm. Long, colour slightly reddish,the tail is blunt and rounded exhibiting a two headed snake.

The sand boa-Eryx conica:About 1 m.long, common in dikes and rice fields. It hunts rats at night.

Rock python-Python morulus:About 6m.long, bold spots on the body and short tail. It is a sluggish creature leaves its resting place when provoked or hungry.

4.Colubridae-Colubrid snakes:

This family compromises a huge number of harmless snakes. Some of them are arboreal,some terrestrial,some fossorial and some agnatic .About 130 species of them occur in India. The known Assam species are :

The Rat snake :Ptyas mucosus is a familiar snake, that speeds away in a flash mainly in agricultural areas. It enters sheds and farms in search of rats.

Wolf snake- Lvcodon aulicus :It is a small slender secretive snake,hides by the day in coil and gets active at night.

Trinket snake-Elaphe helena is a slender,glossy,chocolate brown colour with two prominent dark tripes.

Kukri snake:Oligodon arnensis :It is a pretty snake occasionally found in out houses and big bungalows.It can be recognised by the black marks on the head and bars on the neck.

Vine snake:Ahaetulla nasuata:It is the most common tree snake. It is parrot green in colour and has long tail.

The Green whip-Ahaetulla nasuta :

Bronzeback tree snake—Dendrelaphis trisks is a graceful snake with a long tail,it hides most part of the day in bushes,fast moving and fierce in temperament biting readily.

Golden tree snake—Chrysopelea ornata is a colourful snake marked with reddish rose spots on its back,scrub and thick jungle dwellers,with remarkable power of spinning on the tree branches,venomous.

Indian cat snake:Boiga trigonata :is characterised by its bulging eyes and vertical pupils,long feathery tongue,narrow neck,triangular head and zigzag marks on the body. It can climb trees resting in coil under shade. Lightly or mildly venomous.

Himalayan cat snake:Boiga sp is a common snake of the thick jungle ,feed on tree frogs and lizards. Sometimes on birds and mice .

Stripped keelback -Amphiesma stolata is the common grass snake , recognised by the prominent yellow stripes on the body .It is gentle and hunts on frogs and toads .

Common water snake -Xenochrophis piscator has a thick set body ,nostrils on top of the head .two black streaks behind the eyes. It is harmless but fierce in temper ,feeds on arthropods frogs.

Green keelback -Macropirluhoden pumbicolor is a water snake ,mostly prevalent in the forest areas. When threatened, it.flattens its neck into a hood, has a v-mark on its head .

 

Dasypeltidae-Egg eating snake:

Indian egg eater – Elacliston westermanni is a unique snake as it feeds exclusively on birds

eggs. Harmless but mimics dreaded variety because of its body coloration and black and yellow spots .

Elapidae-Cobras and Kraits (common venomous)

Common Cobra -Naja naja live in plains and jungles, natural hunting places are old termite mounds ,ruined buildings, rock pilesand rat holes


Assam Cobra- Naja naja Kanothia recognised by a white circle round a black spot.

The imposing characteristics is its hood formed as it raises the anterior portion of the body and spread the ribs in the neck region.

 

King Cobra—Ophiophagys hannah is the most feared snake,in size next to python. The temperament of this deadly snake is highly unpretictable.

Common Krait—Bumgarus caeruleus is recognised by its bluish black marks with white cross lines.It has a very large pupil and nocturnal in life. It eats lizards mice,rats and other snakes.

Bandad Krait—Bungaraus fasciatus is distinguished by the prominent broad yellow and black stripes on its back.It is a plains living snake rarely seen in jungle.

Viperidae—Vipers and pitvipers

Big India viper—Vipera russelli is distinctive in colouration and markings,as it posses 23-30 large reddish brown oval spots.It prefers rock crevices,grassy and thorny bushes as its abode.

Bamboo Pit Viper—Trimeresurus gramineus It is a green snake living in bamboo bushes,harmonising the colour with the background. It is timid and slow to defend itself. It lives on small mammals,birds,lizards.

Amphibia

Assam is land which enjoys wide variety of landscape, vegetation, climate and attitude having within this limits scrub-jungles,forests of various types,inland waters and even altitudinal zones. As such,the Amphibian fauna of the State is rich and varied. But the large scale destruction of habitats,particularly deforestation,lowland earth filling,hill cutting and other industrial activities threatened the Amphibia fauna to such proportion that some of the species known about 75 years back are no longer available in their earlier range of habitats. Of late,it is heartening to note that there is some attempt to save whatever left over.

Amphibians includes frogs,toads,newts,salamanders and caecilians .They exhibit endless variations,diverse colour patterns and adaptations to the prevailing habitats. They are seen on land,in water,on trees,under stones,and even underground.

The known(not exhaustive)order and families of Amphibians of Assam are as below:

1.Order:Cymnophiona or Apoda : Fam- Ichthyophidae

The Caecilians :

Limbless amphibia,primarily confined to the forest where they lead a concealed life,in damp, slushly earth,snake like a general appearance and seldom seen above ground,except during very heavy rains. The trail is short or waiting ,eyes are minute and functionless.

The Eastern Himalayan Caecilians- Gegeneophis carnosus, G.fulleri and G.ramaswami,The Indian caecelian -Ichthyophis sikkimensis.

2.Urodela or Caudata :family -Salamandridae :

The Newts :

The newts are sometimes confused with lizards as their body is lizardlike and the laneal tail retained throughout their life. Limbs are short and feeble,incapable of rapid movement,spend more time in water. The only species found in Assam is the Indian Newt-Tylototriton verrucosus. It is characterised by tuberculen skin and large parotids.

3.Order Anura or Salientia :Frogs and Toads :

Members of this order are the most conspicuous of all Amphibians. However,for a layman,the confusion between Frogs and Toads persists. A toad may be a real frog but a frog not necessarily be a toad. We call an Amphibian a Frog which lives in or near water with a smooth slimy skin,while the toad is terrestrial with a rough and warty skin.

Family :Ranidae -The true frogs :

Skipper frog - Rana cyanophlycyis is the commonest frog of Assam. It is recognised by a presence of rounded dark spots on its back and limb,has good ability for floating,small in size.

Cricket frog -Rana Limnocharis,small size,commonly met with a marshy areas, paddy fields and ditches,recognised by a vertebral band.

Green frog-Rana hexadaetyla, most aquatic of all frogs. Lives in dense aquatic vagetation, leaf green in colour.

Bull frog- Rana tigerina. Known for its loud voice and big size, having leopard like spots and median longitudinal trip .Call is resonant quonk-quonk.

Himalayan Frog-Rana liebigii, it exhibits the secondary sexual characters, male has thickened forelegs with conical black spines.

Assam Frog- Rana assameus.s is endemic to Assam and commonly found throughout the State.

Arunachal Frog -Micrixalus borcalis, a small frog whose vomerines is lacking.

Assam Frog- Amolops afghanus .A formosus and A himalayanus . The tadpoles of them found in Assam hills with unusual large oval parotids.

Family- Rhacophoridae (Pat Beng) :The rhacophorids or tree frogs:

They are found in the plains human dwellings and thick jungles of Assam. They are represented by two genera- Rhacophorus and Philantus throughout India . Some of the known species are :Rhacophorus bedimii .R. lencomystax ,R. moloch .Philantus annandalei, P. beddomii, P. charrapnnjiae, P.garo ,etc.

Family -Microhylidae (Narrow mouthed Frogs):

The microhylids are small, stout legged ,burrowing Amphibians, which are not found in or near water .except during the breeding season. The narrow pointed head and tiny bulging eyes are the marking character to spot a microhylid. They remain hidden during the day in their soil burrows in loose sandy soil and become active at night .

The Melanobatrachus indicus , known as black microhylid, is black with a scarlet band near groin and blotch scarlets on the chest. It is very rare. The microhyla is well represented in Assam . Microhyla berdmorei are abundant in lower Assam and Garo hills. The ornate Microhylid ,Microhyla ornata is a beautiful frog with a median sepia marking . It is slender and found among the dried grassy bushes. The Red microhylid , Microhyla rubra is astout bodied frog whose back is marked by broken patches with a red streak in the middle. The genus Uperodon is represented by Uperodon systoma , the fat frog with plumpy body and Uperodon globulosum, whose adults are remarkable burrower and emits characteristics sound like the bleating of a goat. The genous Kaloula is represented by a single .species, the Kaloula taprobanica is the prettiest of all the Indian frogs . The back is dark brown ,head in yellowish ,and a yellow band runs from the eyes to the hind feet . It produces deep guttural call like "Wau -auhh" and are nuisance at night. There are three species that are known inhabiting Assam, of the genus Ramenella . They are Ramanela variegata,the termitaria frog, Ramanella minor ,R, montona and Ramanella tringuleris.

Family = Bufonidae (Chuck Vekuli) .

The Bufos or Toads are the largest group of Amphibians. They could be easily recognised by their fat body , short legs ,awkward hopping and the presence of a pair of parotid glands behind the eyes. These glands secrete a poisonous substance that cause burning sensation in the eyes and mucus linigs.

The common Indian toad is the Bufo melanostictus. It has got black tipped spines in the body with wasts. They haunt mainly the dwelling places hiding in crevices, corners,below stones, logs, etc. It is found on roads,gardens and courtyards. The bufo partictalis is recognised by the well defined parietal ridge and half webbed toes. The Padostibes Kempi abundantly found in Garo hills and lower Assam is an expert climber. The Ansonia ornata is known as Torrent toad, developed webbs between the toes and the larvae undergo a hazardous aquatic growth phase in running hill or forest streams developing snakelike mouth and flat body with a muscular tail. The species Bufoides meghalayana itself constituted a genus, the Bufoides that are available in Assam and Meghalaya. The peculiarity of the toad is absence of parotid glans.

Family= Pelobatidae (odd looking anurous)

The members of this family are called odd looking anurous, with wide mouth, vertical pupil, moist glandular skin and spade shaped horney projections on the sides due to which they are popularly known as 'Spade-foots'. The dig down in mountainous and sandy areas,keep away from light for weeks or months together. The genus Leptobrachium is represented by a single species,the Leptobrachium hasselts from Assam and khasi hills. The other species belong to Megophrys genus with four species Megophrys lateralis, M.parva,M.boettgeri and M.monticola. The tadpoles of the Megophrys posses umbrella mouths.

Family = Hylidae (The Tree frogs):

The Tree frogs are recognised by the original finger tips and toes with an adhesive disc for clinging on trees. They are tree climbers and lead and arboreal life. Most of them are green in colour and change their boy lines to pale green to shining green depending upon the seasons.

The Hyla annectens is a danizen of the forests of Assam and Meghalaya. It makes its presence felt by its loud voice,inflating the vocal sac that buldge the whole throat far exceeding the size of the head. After mating,the male and female swim together for several days.

Endemicity – The endemicity and distribution of Amphibia are usually governed by the availability of the breeding sites and dampness of the habitat. The North Eastern Sub-Himalayan Assam and its adjoining states experience more than 400- 500 cm. for rains annually,so this region is one of the favourite areas of Amphibian fauna above that of Western Ghats which processes moist evergreen forest with rainfall of about 400-500 cm annually. Therefore,the Amphibian endemicity is basically localised in those two areas of India.

Fishes:

The fresh water fish resources of Assam and N.E. india are very rich and varied in forms. Because in the Brahmaputra and Barak valley there are many rivers,streams,hill streams,ponds,natural beels and extensive wet land and marshes which support a great diversity of fish life. Zoogeographically also the fresh water fauna of N.E. India is very interesting and offers exceptional opportunity to study the diversity of forms.

From the known distribution of primary fresh water fishes it has been indicated that the fish fauna comprised of three components:Indian, Indo-Chinese and Indo-Malayan with indigenous Gondwana elements and intrusive components. Of course the Assam fish fauna is dominated by the Indo-Chinese elements as the Indo-Malayan component is comparatively poor. The original fauna found retained on isolated sub-Himalayan hilltops and the hill-tops of the peninsular India,as in those areas even today the suitable ecological niches are available. It is now well known that there was fish faunal transgression from the N.E.India via the Assam valley gate-way and also through Eastern Ghat.

The accounts of primary fresh water fishes occurring within the limit of N.E India with special reference to Assam have been tried to be given here. So this account is not exhaustive but informative and in certain cases accounts of fishes which visit the fresh water through the Brahmaputra river course via Bangladesh and West Bengal have been included but not the exotic species.

Family—Anguillidae (freshwater Eels)

The body elongate,cylindrical,stout,pointed,scales rudimentary,anal fin long. The Anguilla anguilla a fresh water visitor known to occur in the lower reach of the river Brahputra.

Family—Ophicthidae (snake eel)

The body elongate,snake like,head short and conical,no caudal fin. The species Pisodonophis boro is a fresh water visitor of the river Brahmaputra and its tributaries.

Family---Clupeidae (Shads)

The abdomen with scutes,barbels absent,single dorsal fin. The Corica soborna was a visitor to fresh water in the lower reach of the Brahmaputra. the Hilsa ilisha is a regular visitor of the Brahmaputra river course. The other species,Gudusia chapra with oblong compressed body is found in Assam valley.

Family—Notopteridae (feather backs):

The body strongly compressed laterally,dorsal profile is remarkably convexed,eyes large,no barbel. Two species are known from Assam,they are Notopterus chitala and Notopterus notopterus.They are mostly pond and river inhabitants in the Brahmaputra valley,and the Barak valley.

Family—Cyprinidae (carps):

The family contains the largest group of fresh water fishes of Assam. The body of the carps is generally compressed,abdomen rounded of cutting,eyes not covered with skin,scales present,jaws toothless,mouth protrusible,gill openings wide,dorsal ray osseous or articulated.

The carp genus Schizopyge contains about nine species of Snow trouts.with elongate subcylindrical bodies,abdomen rounded,without suctorial disc but with four barbels,mostly in the Kashmir Himalaya,of them two species namely Schizopyge esocims and S.progastus were known to occur in the Brahmaputra upper reach hill streams flowing from Arunachal Pradesh.

The other genus Schizothorax -snow trouts,whose lower slip modified into papillated sucker having four barbels contains three species of which Schizothorax richardsoni along with S. guttatus and S. plagiostomus (synonyms)occur in the hills streams flowing from Bhutan hill of sub Himalayan region.

The genus Chela whose body long compressed,abdomen keeled contains two species,the chela cashius and C.laubuca are known to be distributed along the Brahmaputra drainage system.

The genus Securicula with strongly compressed elongate body and sharply keeled abdomen, contains only one species,Securicula gora known to occur in Assam.

The genus Salmostoma, having compressed elongate body and keeled abdomen contains nine species of which Salmostoma bachaila, S.clupeoides and S.phulo are known to occur in Assam,but the occurrence of other species also can not be ruled out.

The genus Esomus, with compressed elongated body,rounded abdomen and four barbels, known to contain only two species of which Esomus danricus known to occur in Assam and adjoining states.

The genus Danio having subcylindrical compressed and elongate body with rounded abdomen and longitudinal band represented by six species and two sub-genera Danio and Brachydanio. The species of Danio that occur in Assam are Danio aequipinnatus,D.dangila and D.deyario. The sub-genus Brachydanio is known by one species only,the Brachydanio (Danio)rerio.

The genus Rasbora,with compressed elongated body and rounded abdomen is also represented in India by six species,of which Rashbora daniconius and R.rasbora are found in Assam.

The genus Aspidoparia has subcylindrical elongate body, rounded abdomen and without barbels represented by one species,the Aspidoparia jaya in Assam.

The genus Amblyaryngoden having moderately elongate subcylindrical bodywithout upper lip and barbels represented in Assam by one species,the Amblypharyngodon mola.

The genus Barilius having subcylindrical moderately elongate body with sharply pointed head is represented by Barilius barna,B.bendelists,B,vagra and the game fish species B.bola,the Indian trout.

The genus Semiplotus with compressed deep and short body,inferior transverse mouth without barbels is represented in India by one species from Assam,the Semiplotus semiplotus.

The genus Oreichthys with deep short body,transverse small mouth without barbels is represented by a single species,Oreichthys cosuatis.

The genus Puntius having compressed,deep,moderately elongate to short body with short head is represented in Assam by five species. They are Puntius, Chala p.conchonius, P.sophore,P.ticto and P.sarana the culturable species and favourite to the fish eaters of Assam.

The genus Osteobrama with compressed, deep short body is represented by one species in Assam,the Osteobrama cotio. The other five species do not occur in Assam.

The genus Lebeo has moderately elongate body somewhat inferior narrow mouth, lips continuous forming a lateral fold represented by twenty one species in India,of which Labeo rohita, L.calbasu, L.gonius, L.bata, L.buggut and L.dyochelus are found in Assam as important fish. However, the last two species are very uncommon in their distribution in the North Eastern States and Assam.

The genus Acrossocheilus having compressed elongated body with medialy interrupted labial fold and two pairs of barbels,represented by only one species from Assam. This single species is Acrossocheilus hexagonolepic.

The genus Chagunius with elongate body subterminal U-shaped mouth and two pairs of barbels is represented by a single species,the Chagunius chagunio.

The genus Tor (Mehseer) with moderately compressed elongate body and two pairs of barbels,is represented by five species in India,of which Tor putitora,Tor progenius and Tor tor are found in Assam mostly along the Bhutan hills and sub-Himalayan tracks.

The genus Cirrhinus has compressed elongate body, with transverse broad mouth and small barbels present or absent,found represented in India with five species. Of these are Cirrhinus mrigala and C.reba are found in Assam.

The genus Catla having deep shaped body,anteriorly arched wide mouth,without upper lip and barbels has only one species,the Catla catla in Assam.

The genus Crossochelus having somewhat elongate body,very prominent snout overhanging the mouth with a pair of rostral barbels has three species of which Crossocheilus latius and C.burmanicus is known to be found in Assam region.

The genus Garra has compressed short body,rounded abdomen,semicircular transverse inferior mouth and a suctorial disc on the chin with one or two pairs of barbels has been represented by twelve species of which three rapid stream inhabiting species are found in Assam. They are namely,Garra gotyla,G.lamta,and G.mullysh.

Family – Psilorhynchidae

The psilorhynchid cyprinoids have characteristically ventrally attend body,devoid of scales and barbels.

The genus Psilorhynchus having ventrally flattened sub cylindrical body with obtusely pointed flat snout with interiorly transverse small mouth has been represented by four species. Of these,the Psilorhynchus balitora and P.sneatio are found in Assam.

Family - Himalopteridae

The family possesses ventrally much flattened,moderately to greatly depressed body.

The genus Balitora having ventrally fattened, anteriorly greatly depressed flat head with transverse inferior small mouth and paired barbels has been represented by three species,of which the balitora bruice is found in Assam.

Family – Cobitidae

The family fishes possess anteriorly compressed,somewhat cylindrical short body,with papillated thick fleshy lips.

The genus Aborichthys have compressed, greatly elongated body with transverse,narrow inferior mouth papillated thick lips and barbels but without per-orbital spine. Three species are known from India of which Aborichthys garoensis and A. Kempi are found from the lower reach of the Brahmaputra, Garo and Abor hills.

The genus Noemacheilus having almost depressed almost cylindrical body,the small mouth transverse and inferior, lips are thick,fleshy and papillated and 4-8 barbels, are normally seen. There are about 48 species of this genus. of which so far only Noemacheilus botia and N.rupecola are known from Assam.

The genus Botia having moderately deep sort oblong body with narrow inferior mouth and 6-8 barbels is represented with 8 species in India. Of these Botia dario,B.lohachata and the B.rostrata are known to be present in Assam.

The genus Neoeucirrhichthys having slightly compressed elongate body with horse -shoe shaped inferior mouth and rudimentary mandibulan barbels at the corner of mouth is represented by only one species, Neocuicirrhichthys maydelli from Assam only in India.

The genus Acanthophthalmus have a strongly compressed elongate body, small inferior. Mouth with 6 barbels is known by only one species. The Acanthophthalmus pangia from lower reach of Assam, N.E. Bengal and Bangladesh.

The genus Somileptes having stout cylindrical elongate body with horse-shoe shaped inferior mouth, long snout and swollen head with 6 barbels is known by one species only the Somileptes gongota from Assam. N. Bengal and Bangladesh.

The genus Lepidocephalus having moderately compressed elongate body, somewhat arched, inferior mouth and six barbels are represented in India by 8 species. Of these except Lepidocephalus thesmalis,which is found in South India, rest of the species including the well recognised L. guntea are represented from Assam and the Himalayan drainage.

Family Bagridae

This family contains these fishes which have compressed,more or less elongated body with wide gill-cleft,and non-protractible mouth.

Of this,the genus Rita fishes have compressed short body,depressed large head and three pairs of barbels are known by 4 species from India,of which Rita rita is known to be found in Assam.

The genus Batasio has compressed short body, crescentic inferior mouth and 4 pairs of barbels and represented in India by three species.Of these the Batasio batasio and B.tengana species are found in Assam.

The genus Aorichthys look like Mystus and represented in India by two species, Aorichthys aor and A.seenghala and both the species are found in Assam and adjoining parts.

Family : Siluridae

This silurid fishes has compressed elongate body,depressed broad and small head,obliquely cleft superior mouth,2-3 pairs of barbels and without spine anal fins quite long.

The genus Ompok has compressed elongate body, depressed but broad small head, mouth superior with oblique cleft,two pairs of barbels. This genus is represented by three species,all of them found in Assam. The species are Ompok bimaenlotus,ompok pabda and Ompok pabo.

The genus Wallago has a compressed elongate body,depressed large head, snout spatulate and two pairs of barbels.It has got only one species the Wallago attu which is found abundantly in Assam.

The Genus Silurus has a compressed elongate body with an obtusely rounded snout and two pairs of barbels and is represented by three species of which Silurus cochinchinensis is widely distributed in Assam but the other two species S.goae and S.berdmorei are yet to be properly studied in Assam.

Family : Schilbeidae

The fishes of this family has compressed body very wide gill-opening,2-8 barbels,the anal fin is very long and separated from the caudal fin.

The genus Ailia has compressed short body generally compressed short head and 4 pairs of barbels is represented by two species,Ailia coila and A Punctata are found in Assam and its adjoining areas.

The genus Pseudeutropius has compressed elongate body with four pairs of barbels, and adipose short dorsal fin.The genus is represented by two species but uptill now none of them have been reported from Assam.

The genus Clupisoma having compressed elongate body,blunt oval head and four pairs of barbels is represented in India by four species. Of them the Clupisomo garna and C.montana occur in Assam. Another species,the clupisoma prateri is quite prevalent in the Himalyan drainage system,but its occurrence in Assam is quite rare.

The genus Eutropiichthys has compressed elongate body,conical head,four pairs of barbels and a short dorsal adipose fin is represented in India by three species of which Eutropiichthys murius and E.vacha are recorded from Assam and N.E region.

 

Family :Pangasiidae

The fishes of this family are larger in size, have 4 barbels,and fin long but not confluent with caudal.

The genus Paggasius has compressed elongate body,slightly longer upper jaw with two pairs of barbels,is represented in India by three species. Of these the species Pungosius pungosius occurs in Assam and its adjoining states.

Family : Amblycipitidae

The fishes of this family are Loach like, having anteriorly depressed and posteriorly compressed body. There are 8 barbels and the adipose dorsal fin smooth.

The genus Amblyceps having compressed,subcylindrical elongate body.four pairs of brbels and wide transverse mouth represented by only one species,the Amblyceps mangois abundantly available in the foothills of the Himalaya and in some parts of Assam.

Family : Sisoridae

The fishes of this family have anteriorly depressed body and compressed tail,the adhesive apparatus sometimes present or absent but there are 8 barbels.

The genus Bagarius having elongate body,flattened abdomen upto pelvis, greatly depressed, large head, crescentic wide mouth and 4 pairs of barbels with forked caudal fin each part producing flamentus prolongations is represented by one species,the Bagarius bagarius which is quite prevalent in Assam.

The genus Gagata has short compressed body transverse ventral mouth and 4 pairs of barbels is represented in India with 3 species. Of which,the species Gagata cenia could be found in Assam and adjoining states.

The genus Nangra has short compressed body,narrow transverse ventral mouth and 4 pairs of barbels is represented in India by 3 species. Of these the species Nangra viridesceus is known to occur in Assam and adjoining areas.

The genus Erethistes having compressed short body,flattened abdomen upto pelvic base narrow crescentic ventral mouth and 4 pairs of barbels is represented by one species,Erethistes punsilus in Assam and adjoining states.

The genus Erethistoides has greatly compressed elongate body with a hoodlike projection of the snout and 4 pairs of barbels is known from India with two sub-species of which,the Erethisloides montana occurs in Assam.

The genus Hara having compressed moderately elongate body,flat abdomen transverse ventral mouth and 4 pairs of barbels known from Assam by two species,Hara hara and H. horai. The Hara jerdoni is common species of Assam.

The genus Conta has a compressed short body, transverse ventral mouth,the plaited abdominal skin fold forms an adhesive pad and there are four pairs of barbels. The genus is presented by two species, Conta conta and Conta elongata which is profuselyfound along the Garo and Meghalaya hill tracts and in the Brahmaputra valley.

The genus Laguvia has compressed short body,subcylindrical abdomen,wide subterminal transverse mouth and 4 pairs of barbels,is represented in Assam by Laguvia showi out of the 4 species known so far from India.

The genus Glyptothorax having greatly or moderately depressed elongate body,slightly flat to rounded body,narrow transverse inferior mouth, the ventral surface with and adhesive pad and 4 pairs of barbels,is represented by 20 species in India. Of them the Calyptothorax brevipinnis,G.horai,G.pectinopterus,G.striatus and G.trewavasae are well known from this region.

The genus Euchiloglanis has an elongate body,flattened abdomen upto the pelvic fin,transverse ventral mouth and 4 pairs of barbels,is represented by two species from the N.E. States including Assam. They are Euchiloglanis hodgari and E.Kamengensis.

The genus Exostoma havingelongate body, flattened abdomen upto pelvis,more or less crescentic ventral mouth and 4 pairs of barbels is represented so far by one species, Exostoma labiatum from N.E. Hills and Assam.

The genus Pseudecheneis has an elongate body, flat abdomen upto palvic base. The head is having ventrally a broad, oval adhesive apparatus,transverse inferior mouth and 4 pairs of barbels, is represented by only one species the Pseudecheneis sulcatus from foot hill region of N.E. States and Assam.

Family : Clariidae (Catfish)

The fishes of this family posses large, compressed elongate body, gill opening wide and there are well developed 4 barbels. The anal fin long and not confluent with the caudal fin.

The genus Clarius has a compressed elongate body, fairly wide transverse terminal mouth and 4 pairs of barbels,is represented in India by three species,of which the Clarias baitrachus abundantly occurs in Assam and adjoining parts.

Family : Heteropneustidae (Stinging catfish)

The fishes of this family have compressed but moderately elongate body,gill-openings wide and there are well developed 8 barbels.The anal fin long, nearly reaching or united with the caudal fin.

The genus Heteropneustes has a compressed elongate body,transverse, narrowterminal mouth Gill-Chamber with accessory air sacs extending backward to nearly caudal region and 4 pairs of well developed barbels,is represented by a single species Heteropneustes fossillis from Assam.

Family : Chacidae

The chacid fishes have large size robust body,but the head and the anterior part of the body is depressed,there are feebly developed 6 barbels,the adipose dorsal fin is smooth and confluent with the caudal fin.

The genus Chaca has anteriorly depressed short body,abdomen flat,very wide arcuate subterminal mouth and there are three pairs of barbels,is represented by a single species the Chaca chaka from Assam and adjoining areas.

Family :Olyridae

The Olyrid fishes have a loach like elongate body,8 barbels, pectoral fin with a sharp serrated spine and the anal fin is of moderate length.

The genus Olyra has an elongate body,a crescentic narrow anterior mouth, four pairs of barbels is represented by 3 species, Olyra horae, O.Kempi and O.longicauda in Assam.

Family :Belonidae(Gars)

The fishes of this family have a slender,elongate body,jaws are elongate like a beak,wide gill openings and dorsal fin without spine.

The genus Xenentodon has a compressed subcylindrical elongate body,jaws are elongated into a break, abdomen rounded, is represented in Assam by the species Xenentodon cancila.

Family : Syngnathidae( pipe fish)

The fishes of this family have tubular body with cristae and ridges, a single dorsal fin without spine,the tail not pretensible and there is an egg pouch on the abdomen to tail region.

The genus Dorichthys has an elongate body covered with transversely striated shields, rounded abdomen and the jaws are produced into a beak like projection. There is no barbel and the abdomen has an egg pouch. Two species are known of this genus of which Dorichthys unculus so far known to occur in Assam.

Family : Channidae (Murrels)

The fishes of this family have anteriorly subcylindrical elongate body with single dorsal and anal fins.

The genus Channa having anteriorly cylindrical elongate body,the dorsal and anal fins are free from caudal,is represented by 8 species in India. Of those, Channa marulius, Corientalis, C.punctatus, C.amphibious and C.striants are very commonly found in Assam.

There is small to medium species which is very commonly distributed in Assam and known by the species C.gachna gachna.

Family :Synbranchidae (Mud eels)

The fishes of this family have small to moderate body, the dorsal and anal fins are represented by the median folds only.

The genus Monopterus having compressed much elongate body,the gill opening without lateral folds but internally attached to isthmus and the caudal tip is bluntly rounded,is represented by 4 species in India of which Monopterus albus and M.cuchia are found in Assam.

Family :Chandiae (Glass fish)

The fishes of this family have compressed, oblong elevated short body with two dorsal fins and the anal fin without spines.

The genus Chanda has a deep,compressed short body and the anal fin with three species,is represented by 4 species in India of which Chanda nama and C.ranga are found in Assam.

Family :Nandidae (Mud perch)

The fishes of this family have compressed, elevated oblong body, head covered with scales and a single dorsal fin.

The genus Badis having compressed moderately elongate body,the head compressed and large and a single dorsal fin,is represented in India by species,Badis babis and B.dario and both of them are found in Assam.

The genus Nandus has a compressed oblong body and a large compressed head is represented by one species the Nandus nandus from Assam.The genus Preistolepis having compressed short oblong body and compressed short head is represented in India by two species, the prestolepis marginata was known to occur in Assam.

Family :Gobiidae

The fishes of this family have oblong to very elongate body,sea inhabitors but many species found visiting fresh water rivers.

The genus Glossogobius having anteriorly cylindrical,compressed elongate body with oblong united pelvic fins is represented by one fresh water species the Glossogobius giuris which is known to occur in Assam.

Family :Anabantidae (Climbing pers)

The fishes of this family have compressed moderately elongate body and a single dorsal spinous fin,the body and the head is covered with etenoid scales.

The genus Anabus having compressed oblong body and spinous dorsal fin,is represented by two species in India. Of them the Anabus testudineus is very commonly known from Assam.

Family :Belontidae

The fishes of this family have short compressed body,a single dorsal fin with spine and rays and an anal fin with spines.

The genus Colisa has an elevated compressed body,the head moderate and compressed,is represented in India by three species, Colisa fasciata, C.lalius and Colisa sota. All these three species are found in Assam along the Brahmaputra drainage system.

Family :Mastacembelidae (spinny eel)

The fishes of this family have eel-like compressed elongate body,fleshy long snout accommodating concave prolongation of the upper jaw,the nostrils tubular and placed anteriorly on the sensitive snout,the pelvic fin and girdle absent.

The genus Macrognathus having eel-like compressed elongate body,snout long and fleshy, the caudal fin distinctly separated from dorsal and anal fin, scales present, is represented by one species,the macrognathus aculeatus from Assam.

The genus Mastacembelus having eel-like compressed elongate body, conical long snout without transversely strained bony plates on the under surface and scale present,is represented by three species in India. All these three species, Mastachembelus armatus, M.pancalus and M.guentheri occur in Assam.

Family :Polliaiidae (Hill-stream eel)

The fishes of this family have subcylindrical elongate body,the upper jaw possesses a single stony large bone bearing teeth and the dorsal and anal fins long and without spine,the pelvic fin and the girdle absent.

The genus Pillala having eel-like subcylindrical small body,rounded abdomen,the snout with indistinct fleshy rostral appendage bearing the anterior tubular nostrils and no spine anywhere on the body, scales absent, is represented by only one species,the Pillala nidica from Assam and adjoining states.

The genus Garo having eel-like naked body,the dorsal and anal fins confluent with the caudal fin,no spines on the body,scales absent,is represented by a single species,the Garo khjuriai from Assam and adjoining Garo hills.

Family :Tetraodontidae (Puffers)

The fishes of this family are more or less short bodied. The skin covering is modified into small or large spines or lemina in the from of a beak with a cutting edge and covered with a layer of ivory like substances. There is a single dorsal and anal fins without spines, the pectoral fin present but the pelvic fin absent.

The genus Tetraodon having a more or less short body with a broad back compressed into ridges, jaws with median sutures, pelvic fin absent, is represented by only one species,the Tetraoden cutentia from Assam,and adjoining states.

The Game fishes of Assam :

Before the birth of Ichthyology,fishes were known by their local names only. Therefore,there was some confusion in regard to Game Fishes of India upto the third part of the present century. But Thomas (1887,1897), Lacey (1905), Dhu (1923)Phayre (1949),etc., defined game fishes as the fishes of Angling and Sports. The Angling and Sports fishes of Assam are mainly :

1.The Tor Mahseer –Tor tor :

It is a stoutly built fish with a deep body,head is shorter than the body depth. The colour of the body is green and gold,the belly is grey and the lateral sides are pinkish. Light orange,yellow and light blue patches are there in the head. It is having moderately orange and pinkish fin. But sometimes they are uniformly dark in colour. They are omnivorous and breed during August and September of the year.

2.The Putior Mahseer –Tor Putiora :

It is a Grey – hound and Thick lipped Masheer commonly called Golden Masheer. The body is somewhat compressed and streamlined with both the profiles greatly arched. The length of the head is greater than the depth of the body.The colour of the fish varies with the nature and background of the waterbody it inhabits. It is herbivorous usually. It breeds three times in a year during (i)January-February (ii)May-June and (iii)July-September.

3.The Mosal Masheer – Tor mosal :

It is closely allied to Tor Mahseer except the length of the head is equal to or shorter than the depth of the body. There are 4 barbels. The body is anteriorly olivaceous yellow and posteriorly amber colour,the sides are yellowish and the belly is silvery. It is commonly known as copper Mahseer. The young is herbivorous and the adult feeds on carbs,molluses,etc.,being a bottom feeder.

4.The Jungha -Tor progemus :

The body is greyish above the lateral line but the belly is silvery. The base of the scales possesses dark blotches. The head is equal to the depth of the body and the eyes lie in the anterior half of the head. In general look,it is similar to Tor mosal except the fan shaped structure behind the upper lip. Endemic to Assam.

5.The Bokar- Acrossocheilus Hexagonolepis:

The Bokar of Assam possesses large scales and therefore, it should have been considered a mahseer. However, It only differs in the interrupted post – labial groove and the red eyes. It is a graceful fish, the ground colour of the body is olive on back, yellow brown and blue on the laterals and the belly is silver in colour. There are four barbels.

6.The Indian Trout- Raimas bola:

This fish is not a true trout but it has the appearance of a trout having streamlined body and body spots. The head is pointed, body is compressed and the scales are small. The back is greenish grey and the ventrum is silvery separated by a longitudinal golden stripe. It weighs below 1 kg but get hooked nicely with fly jump out of water. It is restricted to the hilly parts of Assam.

7.The Alwan-- Schizothorax richardsonii:

It is a streamlined fish, scales are small, but slightly larger along the anal aperture. There is no adipose fin, the chin bears a sucker. The body is greyish silvery above and light silvery below with many black spots.

8.The Dinnawah- Schizothoraichthys progas:

It occurs in the same habitats as Alwan but differs tus from the S. richardsonii in the absence of ventro cephalic hard papillated plate.

It is a deep bodied fish, uniformly silvery in colour, rarely dark spots may occur but the tip of the fins are usually black.

9.The Rohu (Labeo rohita):

It is a graceful fish with thick and fringed lips, the snout is depressed, mouth ventral, 4 barbels, the dorsal fin is long,15-16 rays. The back is brownish and the sides are silvery, abdomen is more silvery but fins are dark.

It is a valuable food fish of India, vegetable feeder, attains a length nearly upto a metre. It can be stocked in tanks, usually found in slow moving water, pools, rivers and is one of the commonest major carps of India.

It is prevalent in North East, North and central Indian natural water, although introduced nearly in all parts of India as pond or flood culture fish.

10.The kalbose (Labeo Calbasu):

It is a blackish green fish becoming lighter below, fins are black, upper tip of the caudal fin usually tipped with white, the lips are fringed, horney covering inside each jaw,snout bears pores, 4 barbels.

They can be stocked in ponds and flood culture in North East Indian natural water. They are prevalent more or less throughout India.

11.The Katla (catla catla)

The back of this fish is greyish, silvery on the sides and abdomen, fins are dark coloured, scales have grey silvery tinge.The dorsal profile is more curved than the ventral,mouth wide, lower jaw prominent, upper lip absent,pores are sometimes present on the snout.

It is an important,more productive food fish which attains up to 1.83 metres in length and can be easily employed in pond and flood culture in Assam and North East, but found throughout India.

12. The Mrigal (Cirrhinus mrigala)

The dorsal profile is slightly more curved than the ventral,upper lip is entire,dorsal fin long,two sides and belly silvery,pectoral,ventral and anal fins are orange, ujheyes are golden.

It grows upto 91 cm in length,excellent for stocking in tanks and flood culture in Assam,herbivorous, breeds in running water, found throughout India.

13. The White Carp (Cirrhinus cirrhosa)

The body is silvery, scales having a reddish centre, abdomen dull yellowish, fins are Grey, dorsal profile is more concave than ventral, 4 barbels, small tubercles on the snout.

It grows up to 46 cm in length, remains mostly in the lower section of water,can be stocked in tanks in Assam.

14.The Chaguni (Chagunius Chagunio)

The body is uniformly silvery with dispersed pink tinge, fins are reddish with lighter edge, dorsal fin edged black, the head is compressed with flat sides, overhanging snout is divided into central and lateral lobes,the snout and seeks in males are with tubercles, fewer in female, dorsal spine serrated, scales are small, 4 barbels.

It grows up to 46 cms in length,found throughout India except peninsular region.

The Cat-fishes

The next largest group is the catfishes with scalless body, strong teeth in the jaws,snout with 1-4 pairs of barbels,the dorsal and pectoral fins bear strong spine.

15.The Boali(Wallago attu)

The dorsal side of the body olive with golden, lower part of the body and slides lighter ,anal and caudal fins are somewhat blackish, sides often cream coloured. The head is large,snout depressed,mouth wide,jaws with conical teeth, posterior body laterally compressed, dorsal fin very small,anal fin long.

It is a powerful fish of large size, omnivorous, stays near the bottom of the water, it grows upto 180 cms in length and 45 kg in weight,undesirable in big reservoir, natural in flood prone beels in Assam, found throughout India.

16. Seenghari or Tengra (Mystus Seenhala)

The back is brownish, sides and belly are silvery, a black spot at the base of the posterior end of the adipose fin, snout is flat and wide,a bony inter neutral shields between the basal bone of the dorsal fin, median groove on head is short, maxillary barbels extend upto the end of dorsal fin. Distributed throughout India in riverine habitats.

17. Aar (mystus aor)

Allied to Seenghari but differ in the wider mouth and longer maxillary barbels,median groove on head is long,dark bluish on the back, gradually becoming whitish on the sides and belly,fins yellowish,dorsal and caudal stained black,tip of adipose fin bears a dark spot. It attains 1.8 metres in length,freshwater dweller,restricted mostly to rivers and riverine flood areas in Assam.

18. Khagga (Rita rita)

The back is greenish grey, sides and abdomen silvery, head is granulated, pectoral process is massive and stout, anterior and posterior nasal opening are away from each other,6 barbels. It is also found in north India.

19. Pungus (Pangasius pangasius)

The body and the head dusky green above and white below with a purple gloss on the sides,sides of the head golden yellow, fins are whitish. Body laterally compressed,head somewhat depressed,eyes are on the lower anterior of the head, nostrils wide apart, mouth ventral,there are 4 barbels.

It feeds on decaying matter,resides mostly in the lower reach of river,grows upto 1.5 metres in length and commonly known as fresh water shark, nocturnal in habit,found throughout India.

20.Silond (Silonia silodia )

Elongated and compressed body, eyes lateral,nostrils wide apart,mouth is slightly ascending,back dusky green,sides silvery,dorsal and caudal fins greenish,others white, opercule orange to yellow, irish orange,dorsal fin much in advance than ventral,2 maxillary barbels.

It is carnivorous,feeds on prawns,crabs and small fishes,remains in strong streams and grows upto a metre in length,found in Brahmaputra and Gangetic plains.

21.Vacha (Eutropitchthys vacha)

Body elongated and compressed, mouth cleft wide slightly oblique, dorsal fin lies opposite to ventral,body silvery with black greyish with tint of cobalt blue, patches of vermilion on jaw,orbital margin,gills cover pectoral fin and ventral sides of the body,fins are greyish, 8 barbels.

It is carnivorous on small fishes and insects mostly surface feeder, destructive to pond fisheries,length about 35 cms, prevalent mostly in the North east, and Eastern states of India.

  1. Garna Bacha ( Chupisoma garna )

Body elongated and compressed, herring like, part of the abdomen keeled, mouth sub-terminal,nostrils are posterior and wide, back is green, sides and belly silvery, fins are translucent,dorsal and pectoral fins dotted with black,head and shoulder bear golden gloss.

It is a carnivorous bottom feeder and feeds on crustaceans, small fishes and insects, grows upto a metre in length, weighing upto 12.2 kgs. It occurs in Brahmaputra,Ganga etc.

23. Goonch (Bagarius bagarius )

The head and anterior body part depressed, head is bony and rough on upperside, tail is narrow and whip like mouth behind the snout,ventral,dorsal and pectoral fins with strong spines,caudal fin deeply forked, both the part producing filamentous processes, body colour yellowish green or to its habitat background, the yellowish sides sometimes with patches of pink, black spots are irregularly scattered on the body, fins and there are two irregular black markings behind the dorsal adipose fin.

It is predaceous in habit and known as fresh water shark,grows upto 2 metres in length and weighs up to 135 kgs,hence is the largest fresh water fish of India.

It is also known as living fossils as it has been existing for the last 5 million years (Tertiary period) without evolution and fossils of this fish have been recorded from Tertiary deposits of Siwalik rocks in India.

24.Brown Trout

The body is brownish,dark spots along the upper part not below lateral line,the dorsal fin above the pelvic and adipose fin above the anal fin . In India, it is found in higher reaches and River Brahmaputra, Beas and Jhelum.

25.Murral (Channa marulins)

The colour of the fish differs in different environment, normally the body is greyish green, lighter below,somewhat snake like,covered with scales sometimes with red, dorsal and anal fins are long, amphibious, as it can stay outside water for quite a long time. Youngs are brilliant orange with lateral bands and adults have 5-6 cloudy bands below the lateral line, a large black ocellus occurs at the upper base of the caudal fin.

It grows up to 1.2 metres in length and found throughout India.

Conservation of fishes

A few few words added on the conservation of fishes particularly the game fishes are found to be essential as in recent years the quality and quantity of fish fauna of the inland water of Assam and adjoining areas have shown a sudden annihilation.

The major causes are :

1.Pollution of water by sewerage disposal and chemical wasters to running and standing water bodies.

  1. The absence of fish ladders due to construction of embankments and dams.

  2. Introduction of exotic fast breeder like tilapia in fresh water carp habitats.

  3. Over-fishing and blasting of big water bodies by unlawful killers and uses of unapproved fish gears for fishing reduced tremendously the fish population of Assam water bodies in particular.

Rodents (Rats and Squirrels).

Rodents,specially the rats,mouse,etc. are known from the dawn of human civilisation. Not only in the multiplicity but also in the enormous, swarms of individuals, the group stands unique among mammals. They are cosmopolitan in their distribution and have adapted themselves to all sorts of ecological habitats,arboreal,terrestrial,subterranean to aquatic. They are equally at residential home, godown, fields, bamboo grooves, at the snowy height of Himalaya as well as in the hot sandy deserts.

Rodents create immense problem in the field of agriculture,horticulture and other material possessions . They are also responsible for the spread of some dreadful diseases like plague, murine, typhus, etc.They are also known to be the source of a number of Zoonotic diseases such as leptospiral jaundice, salmonellosis ,rat-bite fever,etc.

Taxonomy :The rodents in India are represented by seven families,39 genera and 99 species,out of which the status of 9 from Andaman and Nicobar Island is not yet very clear. However, all the families are not discussed here,as many of them do not occur in the North Eastern India States and Assam in particular. Therefore ,here only those families that occur in North eastern States including Assam,have been included.

Family Sciuridae

1.Petaurista candidulus. Wronghtoni's flying Squirrel

2.Belomys pearsoni.Hairy flying squirrel

3.Petaurista petaurista.Giant flying Squirrel

4.Hylopetes alboniger.Pasty coloured flying squirrel.

5.Tauniops macelellandi.Himalayan Squirrel.

6.Calloseiurus pygerythrus.Geoffroy Squirrel.

7.Dremomys lobriah.Orange belly Squirrel.

8.Dremomys pernyi.Long nosed Squirrel.

9.Rotufa bicolor.Malayan Squirrel.

ASSAM STATE GAZETTEER 84

Family Rhizomydae :

10.Connomys badius.Bamboo rat.

11.Rhizomys pruinosus.Hoary bamboo rat.

Family Hystricidae :

12.Arherurus macrourus.Asiatic porcupine

13.Hystrix indica.Crested Porcupine

14.Hystric Hodgson.Himalayan Porcupine.

Family Cricetidae :

15.Eothenomys melanogaster.david's vole.

16.Pitymys sikimensis.Sikkim vole.

17.Apodemus sylvaticus.Common field mouse.

18.Micromys minutus.Harvest mouse.

19.Chiropodomys gliroides.Tree mouse.

20.Vandeleuria obracea.Indian Tre mouse.

21.Rattus rattus.Mouse Rat.

22. Rattus uitidus.Himalayan Rat.

23. Rattus bowersi.Bower's Rat.

24.Raflus manipulus.Manipur Rat.

25. Rattus niviventer.White belly Rat.

26. Rattus fulvescens.Chestnut Rat.

27. Rattus eremoriventer.Dark tailed Rat.

28 Rattus edwardsi.Edward's Rat.

29. Rattus sabanus.Noisy Rat.

30.Dacnomys millardi.Giant Rat.

31.Hadromys humei.Hume's Rat.

32.Golunda ellioti.Bush Rat.

33.Bondicota bengalensis.Bandicoot Rat.

34. Bondicota indica.Large Bandicoot Rat.

35.Mus musculus.House mouse.

36.Mus dunni.Field mouse

37.Mus booduga.Indian field mouse.

38.Mus cerbvicolor.Fawn mouse.

39.Mus pahari.Sikkim mouse.