Abstract
Common names: Biting catfish, Jol mangur or Pahari mangur (Bengalese). Conservation status: Endangered in the opinion of the authors (but not yet included in IUCN Red List). Identification: A small (maximum 90 mm TL, 3 g) loach-like, olive brown siluroid fish with a cup-like fold of skin above and anterior to the base of the pectoral fin behind the gill openings. D 1 + 6 + 0, P 1 + 6, V 5, A 11, C 24. Dorsal and pectoral spines covered by a sheath. Base of the dorsal and pectoral fins swollen. Lateral line system absent. Drawing by Subhash Singh. Distribution: This amblycipitid catfish is rare in the north-eastern region of India (foothills of the Himalayas) and in Nepal, Burma and Thailand (16‐31 N and 74‐99 E). Abundance: No population estimate exists. The main catch by fishermen using trap nets is made in the summer months (April to June). We collected 70‐100 specimens from streams in the foothills of the Himalayas from 1980 to 1988. Habitat and ecology: A. mangois lives under pebbles and stones in shallow, torrential streams which are liable to dry up into a series of pools and puddles in summer. It is able to survive in shallow pools as it is an air breather. Singh et al. (1989a) provide a detailed account of their air-breathing organs. The fish floats upside down in hypoxic water (DO = < 4 ppm) by filling its stomach with air. Singh et al. (1990) consider that this habit is a respiratory adaptation for utilizing oxygen-rich water in the surface layer. The jol mangur is an active predator that feeds mostly on copepods and insect larvae. It inflicts wounds with its pectoral spines. Reproduction: The fish has a pair of small, unbranched ovaries and branched testes. In some specimens a single ovary is found. In our collections, the number of females is less than the number of males (1 : 10, n = 80). The breeding period is in summer (June‐July). The young attain a considerable size in order to withstand the force of raging torrents during the rainy season. Threats: This species is caught by native fishermen as a by-catch when netting for cobitid fishes. The exploitation of natural resources in the main river and its tributaries threatens A. mangois. Hundreds of labourers are engaged in collecting pebbles and stone-chips from the river bed during summer. These activities destroy the habitat of A. mangois and threaten its survival. There are also problems with catchment mismanagement in the foothills of the Himalayas. Conservation action: No attempt has been made as yet to conserve the jol mangur, nor is this species listed in a national or international Red List, although such a listing would be justified. Conservation recommendations: Fishing for small cobitid fishes in mountainous streams in the Himalayan foothills should be banned. The natural habitat and breeding grounds of A. mangois should be preserved by prohibiting sieving for pebbles. Remarks: A. mangois has a remarkable phylogenetic significance as it shows parallelism with air-breathing estuarine gobies as far as the development of their air-breathing organs is concerned (Singh et al. 1989b).
Published Version
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