The sorting of some fishes in the field / fresh market catches was made on the basis of the presence of considerably long filamentous extensions of skin around mouth (barbels) and absence of scales on the body (smooth skinned). They were placed under ‘Lot 11’, tentatively labeled as ‘CATFISHES’.
Some important diagnostic features of ‘CATFISHES’ [Order: Siluriformes], to be segregated ahead, need a special attention viz.,
- Barbels:
As one of the most diagnostic features, all Catfishes possess long or short, paired filamentous extensions of skin around the mouth, called as ‘Barbels’. Maximum 4 pairs of barbels, viz., 1 pair Nasal or Rostral barbel, 1 pair Maxillary barbel and 2 pairs of Chin or Mandibular barbels (i.e., outer mandibular and inner mandibular) are noticed.
- Adipose Dorsal Fin:
In addition to a Rayed Dorsal Fin, in most catfishes there is another dorsal fin behind the first one. It is only a fleshy (or leathery) vertical extension of skin, called Adipose Dorsal Fin, exhibiting some prominent Genus/Species specific features (may be colour marking or size).
- Adhesive Apparatus:
If some catfishes from fast flowing rocky streams are viewed ventrally at the chest region, there will be found a special structure with folded/pleated skin. This is called as adhesive apparatus, used for clinging to the stones, rocks or boulders.
- Habitat preferences by Catfishes:
Varied kind of habitats are preferred by catfishes included in ‘Lot 11’, ranging from fast turbulent to slow running, weedy or marshy stretches with rocky, bouldery, pebbly or muddy beds. Also, they have also been successfully living in aquaculture ponds /reservoirs (as in the plains). As will be seen after segregation, their body is more or less suited to special living conditions with special adaptations viz., shape of body, presence of adhesive structures, spines in the dorsal or pectoral fins, accessory respiratory organs etc.
- Species segregation:
The sample Catfishes (Order: Siluriformes) procured from the aquatic habitats of Doon Valley (Uttarakhand, India), included here under Lot 11 in the field, are found to belong to 5 Genera viz., Amblyceps (Family: Amblycipitidae), Glyptothorax (Family: Sisoridae, Subfamily: Glyptosterninae), Clarias (Family Clariidae), Heteropneustes (Family: Heteropneustidae) and Mystus (Family: Bagridae).
The Genera and Species belonging to them can be segregated on the basis of the following prominent features:
(i) Adhesive apparatus present on the chest (Glyptothorax; Family: Sisoridae, Subfamily: Glyptosterninae).
(ii) Rayed dorsal covered by thick skin and colour of body fleshy- or chest nut brown (Amblyceps; Family: Amblycipitidae).
(iii) Long-based dorsal and anal fins (Clarias; Family Clariidae).
(iv) Long-based anal fin (Heteropneustes; Family: Heteropneustidae).
(v) Dark longitudinal band(s) along the lateral line and often a shoulder spot (Mystus; Family: Bagridae).
(i) Segregation of species with a thoracic Adhesive apparatus
(Glyptothorax; Family: Sisoridae, Subfamily: Glyptosterninae)
[Gk.glyptos, carved; thorax, breastplate or the part of covered by it]
Sisorid catfishes belonging to Genus Glyptothorax are benthic, dwellers of torrential streams; fixing or adhering to the rocks or boulders with the help of a thoracic adhesive apparatus made of folded pleats of skin (parallel or oblique to the longitudinal axis of the body) thus preventing them from being washed away by the strong currents. Other characters include:
Body elongated, strongly compressed laterally behind the pelvic fins, sometimes with unculiferous tubercles (= bearing ‘unculi’, horny projections arising from single cells, an adaptive feature of the epidermis of Ostariophysan Fishes). Head, covered with thick skin and depressed. Mouth inferior, upper jaw the longer. Lips papillated. Eyes dorsal and small. Pectorals horizontally spread, plaited below and with a strong, broad, serrated spine having antrorse teeth (directed forward or upward) along the inner edge.
UNCULI
‘Unculi’ are the horny projections arising from single cells of the epidermis in Ostariophysan Cyprinoidei (Carps, Loaches etc.) and Siluroidei (Catfishes). They have also been found in Characoidei (Characins) and Chanoidei (Gonorynchs). Functionally, they are significant on the lips, on the ventral surface of paired fins (pectoral and pelvics), on epidermal plaques and tubercles in various catfishes, on the thoracic adhesive apparatus of Sisorid Catfishes and mental adhesive disc of the Cyprinid Genus Garra. Overall, ‘unculi’ function for mechanical protection of the skin, rasping and adhesion.
Genus Glyptothorax has been found to include 2 common species, found in the streams of Doon Valley:
1
- Skin granulated. Maxillary barbels reaching to middle of pectorals, outer mandibulars to the pectoral base, inner mandibulars to gill opening, nasals to the anterior margin of eye. Thoracic adhesive apparatus as long as broad, without a central pit but with a smooth and clear area. Uniformly dark brown above and on the flanks with a light orange streak running along the dorsum up to the base of caudal. Dorsal and caudal fins greyish and edged yellow; often the dorsal with blackish bar in the middle.
…………………. Glyptothorax pectinopterus
PHOTOGRAPHS OF Glyptothorax pectinopterus
2
- Skin rough with tuberculations. Adipose dorsal short-based. All barbels shorter than head; nasal very short and hardly reaching the eye; maxillaries reaching to hinder end of orbit; outer mandibulars longer than the inners and not reaching the gill opening. Thoracic adhesive apparatus feebly developed (with narrower folds), without a central pit. Caudal peduncle slender. Dark brown or cement grey above and on the flanks, dirty yellow below. Often the head, flanks and fins mottled.
…………………. Glyptothorax telchitta
PHOTOGRAPHS OF Glyptothorax telchitta
Habitat preferances by Glyptothorax sp.
(ii) Segregation of species with Rayed dorsal covered by thick skin and colour of body fleshy-brown
(Amblyceps; Family: Amblycipitidae).
Amblycipitid catfishes belonging to Genus Amblyceps are small-sized (2.1 – 8.4 cm), benthic, dwellers of pebble-strewn torrents, often hiding among the stones and pebbles where isolated trickling streams are flowing faster along the gradient. A good number of specimens were gathered after dislodging the stones, pebbles or shingles in a small drag net placed downstream.[Curiously enough, juveniles of Channa gachua and some cobitids like Acanthocobitis sp. or Lepidocephalichthys sp. also shared similar kind of habitat conditions].
Genus Amblyceps is represented by only one species viz., Amblyceps mangois, characterized as under:
- Body tapering uniformly from head to tail in the horizontal plane but is almost parallel-sided in the vertical plane. Head flat and wide. Mouth transversely wide; lower jaw slightly longer; lips thick and fimbriated. Eyes small, superior, subcutaneous. Nasal barbels extend up to hind end of the head; maxillary up to pectoral fin base; outer mandibulars beyond pectoral fin base and inner mandibulars up to isthmus. A cup-like depression below the opercular flap and above base of pectoral fin present (considered to be associated with respiratory function). About 3/4th rayed dorsal covered with thick skin, concealing the spine also. Adipose dorsal originates opposite the anal, often reaching up to base of caudal fin. Pectoral fins with a weak spine concealed in the skin. Anal fin base also covered with thick skin, commences opposite the adipose dorsal. Caudal fin with upper lobe the longer. Colour fleshy brown (chestnut brown) along dorsum and flanks; olive brown along the belly.
………………….. Amblyceps mangois
Amblyceps mangois: An assemblage of fresh specimens. As for the characteristic of a catfish, mark the presence of 4 pairs of prominent barbels (blue arrows). Also observe dark brownish (or chestnut brown) colouration on the dorsum and flanks (orange arrows) and lighter along the belly (red arrow).
(iii) Segregation of species having Long-based dorsal and anal fins
(Clarias; Family Clariidae)
Clariid catfishes, belonging to Genus Clarias (14.0 – 28.0 cm), are mostly the inhabitants of stagnant, swampy or marshy, weedy streams or ponds with muddy or pebbly bed. Usually, they are caught in association with Heteropneustes fossilis, Channa sp., Trichogaster sp., Puntius sp., Mastacembelus sp.etc.
Genus Clarias is represented by only one species viz., Clarias batrachus, characterized as under:
Body elongated, subcylindrical up to pelvics but compressed laterally beyond up to caudal region. Head depressed covered with bony plates. Eyes small, superior with free orbital margins. Mouth terminal, transverse, with upper jaw the longer. Maxillary barbels reaching up to pectorals, the rest being shorter. All fins covered with thick skin. Dorsal fin long-based (62 – 76 fin rays) without a spine. Anal fin also long-based (45 – 58 fin rays). Pectoral fins with a strong spine, concealed in the skin, finely serrated along both the edges (or rough externally). Caudal rounded. Body colouration variable, darker to lighter shades of reddish-brown or grey-black; dorsal, anal and caudal fringed red.
An accessory respiratory labyrinthine organ present attached to II, III and IV branchial arches.
…………………………. Clarias batrachus
PHOTOGRAPHS OF Clarias batrachus
Exotic specimens of Clarias (Clarias gariepinus) from Doon waters
While venturing into the filed for routine collection of fishes in Doon Valley, a few secimens of Clarias were also caught from the Tons River stretch between Robbers Cave and Tapkeshwar (Western Doon Valley). They were instantly found to be different in colouration and size from Clarias batrachus.
After putting the specimens under close observation, they were found to belong to Exotic variety of Clarias i.e., Clarias gariepinus (the African sharptooth catfish). The colouration appeared mottled grey along the dorsum and flanks and lighter (pinkish white) on the belley [dark coloured specimens were recently observed in market catches of Banda, UP, India, on 16.12.2019; may be from cultivable or village ponds].
Akin to C. batrachus, their body is also slender, dorsal and anal fins long, caudal rounded, pectorals with a serrated spine, head flattened with bony plates, mouth terminal with 4 pairs of barbels and papillated lips.
Obviously, like the other most popular exotic aquaculture species, the Chinese Cyprinid, Cyprinus carpio, which has also been found entry into the natural waters of Song River (Eastern Doon), the African Catfish in question is also an accidental escape into the natural waters form cultivable areas or otherwise. There are many such instances of escape of exotic fishes reported from Northern to Southern India where they have tended to successfully colonise natural water bodies.
It was as early as 1970s, when rearing of African catfish was started in Central and Western Africa. In India, the African catfish entered into culture system via Bangladesh through private fish traders without official permission and it rapidly spread into whole of the country. It was first propagated on a large scale along the north-eastern belt, mainly in the state of Assam. Since then, it has been reported to have entered into natural water bodies, posing a great threat to the native species by way of competition, predation and environmental modification.
Though the Indian Government prohibited its culture in ponds and tanks in 2000, many state Goverments have not been able to effectively enfore the ban, leading to illegal farming and escape of exotic varieties to our natural water bodies.
Their presence in the streams of Doon Valley is also not an exception, as happened in other states of India.
PHOTOGRAPHS OF Clarias gariepinus
Ventral view showing the transverse cleft of mouth, papillated lips, barbels and pinkish white colouration.
Ventral view showing the transverse cleft of mouth (red arrows) and papillated lips (yellow arrows).
(iv) Segregation of species having Long-based anal fin
(Heteropneustes; Family: Heteropneustidae).
Heteropneustid catfishes are belonging to Genus Heteropneustes (11.0 – 18.0 cm) are mostly the inhabitants of stagnant, swampy or marshy, weedy streams or ponds with muddy or pebbly bed. Usually, they are caught in association with Clarias batrachus, Channa sp., Mastacembelus sp. etc.
Genus Heteropneustes is represented by only one species viz., Heteropneustes fossilis, characterized as under:
- Body elongated and compressed laterally up to caudal region; dorsal ouline being straight whereas the ventral one arched. Head depressed covered with bony plates. Eyes small, lateral with free orbital margins. Mouth small, terminal, transverse, with upper jaw the longer. Maxillary barbels reaching up to middle of pectorals or to the base of pelvics, outer and inner mandibulars extending beyond tip of pectorals; nasal barbells extend up to middle of pectorals.. Dorsal fin short (6 – 7 fin rays) without a spine; situated closer to snout. Anal fin long-based (60 – 79 fin rays); 3/4th covered with thick sheath. Pectoral fins with a strong spine, finely serrated internally but with few external serrations at the anterior end (the spine is poisonous and dangerously inflicted when handled live; often broken off by fishermen). Pelvic fins closer to the anal base. Caudal rounded (one specimen exhibited and forked caudal fin; may be teratological manifestation). Body colouration leaden or dark purplish brown; youngs being reddish brown.
An accessory respiratory organ is present in the form of an air sac, extending posteriorly from the gill chamber.
- Body elongated and compressed laterally up to caudal region; dorsal ouline being straight whereas the ventral one arched. Head depressed covered with bony plates. Eyes small, lateral with free orbital margins. Mouth small, terminal, transverse, with upper jaw the longer. Maxillary barbels reaching up to middle of pectorals or to the base of pelvics, outer and inner mandibulars extending beyond tip of pectorals; nasal barbells extend up to middle of pectorals.. Dorsal fin short (6 – 7 fin rays) without a spine; situated closer to snout. Anal fin long-based (60 – 79 fin rays); 3/4th covered with thick sheath. Pectoral fins with a strong spine, finely serrated internally but with few external serrations at the anterior end (the spine is poisonous and dangerously inflicted when handled live; often broken off by fishermen). Pelvic fins closer to the anal base. Caudal rounded (one specimen exhibited and forked caudal fin; may be teratological manifestation). Body colouration leaden or dark purplish brown; youngs being reddish brown.
…………………………. Heteropneustes fossilis
PHOTOGRAPHS OF Heteropneustes fossilis
Heteropneustes fossilis: Pectoral fin and spine magnified.
(v) Segregation of species having dark longitudinal band(s) along the lateral line and often a shoulder spot
(Mystus; Family: Bagridae)
Bagrid catfishes, belonging to Genus Mystus, are mostly the inhabitants of fast or slow flowing, stagnant, swampy or marshy, weedy streams or ponds with muddy or pebbly bed. Usually, they are caught in association with Clarias batrachus, H. fossilis, Channa sp., Mastacembelus sp. etc.
Genus Mystus is represented by 2 species, characterized as under:
- Body elongated and compressed laterally. Dorsal profile arched, rising gently from the tip of snout to the base of occipital process. Head depressed, with median longitudinal groove on the upper surface reaching to the base of occipital process. Occipital process long, narrow, reaching to base of dorsal fin. Snout obtuse. Eyes lateral and rounded. Mouth terminal, transverse, upper jaw the longer. Maxillary barbel longest, reaching to the anal fin base; nasal reaching base of occipital process; outer mandibular reaching tip of pectorals and inner mandibulars up to base of pectoral fins. Dorsal fin with a strong spine, inner and external face finely serrated at the tip. Adipose dorsal long-based. Pectoral fins low, with a strong spine bearing 8 – 10 retrose teeth (directed backwards) on the inner face. Caudal fin forked, upper lobe the longer. Colouration greenish to bright yellow; darker along the dorsum; pale brown along the flanks; porcelain white along the belly; usually with 4 dark bands along the flanks (2 above and 2 below the lateral line); a prominent shoulder spot present.
………………………….Mystus tengara
PHOTOGRAPHS OF Mystus tengara
A live specimen of Mystus tengara. Observe the 4 pairs of barbels, dark bands on the flanks, long adipose, longer upper caudal lobe and respiratory movements etc.
- Body elongated and compressed laterally. Dorsal profile arched, rising high from the tip of snout to the base of occipital process. Head depressed, with median longitudinal groove on the upper surface shallow, reaching to the base of occipital process. Occipital process long, narrow, reaching to base of dorsal fin. Snout obtuse. Eyes lateral and oval. Mouth terminal, transverse, jaws almost equal. Maxillary barbel longest, reaching to the anal fin base; nasal reaching hinder border of eye; outer mandibular reaching to base of pectorals and inner mandibulars quite shorter. Dorsal fin with a smooth or often finely serrated spine. Adipose dorsal long-based. Pectoral fins low, with a strong spine, with 10 – 15 retrorse teeth on the inner face. Caudal fin forked, upper lobe the longer. Colouration greyish, greenish to bright yellow; darker along the dorsum; pale brown along the flanks; porcelain white along the belly; usually with 1 fainter dark band along the lateral line with similarly fainter 1 above and 1 below it. Shoulder spot is diffused one.
………………………….Mystus bleekeri
PHOTOGRAPHS OF Mystus bleekeri
IMPORTANT TAXONOMIC NOTE ABOUT Mystus tengara
In the literature there have been instances expressing controversy about the identity of 2 closely resembling Mystus sp. viz., M. tengara and M. vittatus; on account of the presence of longitudinal stripes on the body. M. tengara has many a times been considered synonymous with M. vittatus. Since the present material largely agrees with the observations of Vishwanath et al., (2007) [Fishes of North East India], it has been kept identified as M. tengara, M. vittatus being regarded as a separate species.Mystusmt
Pl. read the research paper ‘On the Fishes of Banda district I –Faunistics and bionomics of Mystus Scopoli (Sub-Genus: Mystus) Species (Bagridae)’, Indian J. Phy. Nat. Sci., 5(4), (1985)
