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his month we are entering new territory with the first factsheet on a relatively new family (Wang et al 2016), Ailiidae, with the monotypic species, Ailia coila.

Ailia coila

Ailiidae is a family of catfishes native to Asia. They usually have dorsal fins with a short base and a spine, but Ailia lack a dorsal fin altogether. Most of these species in the Ailiidae family were formally in the Schilbeidae family but were reclassified and moved by Wang et al in 2016. As of 2019 there are 13 genera in this family.

Ailia coila

Ailia coila was originally described as Malapterurus coila by Hamilton (1822) from freshwater rivers of West Bengal. Gray's (1830) illustrations of Acanthonotus hardwickii, Silurus (Acanthonotus) cuvieri and Malapterus (Ailia) bengalensis and Günther's (1864) description of Ailia affinisre are all currently synonymized to Ailia coila (Ferraris 2007).

Remarks: Ailia coila is a widespread species that has undergone significant decline in its population due to overexploitation as a food fish in parts, if not throughout its entire range. However, potential problems in taxonomy and problems in extrapolating data from localised studies for the entire subcontinent (to fully assess population decline) make it impossible to accurately assess this species. Due to limited evidence available that suggest significant declines in population as a result of overfishing, the species is assessed as Near Threatened (a possible decline of close to 30% over its entire range over a ten year period) with urgent need to study the threats, harvest levels and population changes in this species. (Red List of Threatened Species 2010)

Ailia coila lives in shoals in mayor freshwater rivers and connected waters. It is heavily utilized as a food fish (Talwar and Jhingran 1991, Patra et al. 2005, Mishra et al. 2009). Heavy harvesting of the fish could be a threat to its population (Patra et al. 2005, Mishra et al. 2009).

Acanthonotus hardwickii, Ailia affinis, Ailia bengalensis, Malapterurus coila, Malapterurus cuvieri, Malapterus bengalensis, Silurus cuvieri

Gangetic ailia

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Asia: Pakistan, India, Bangladesh and Nepal.

28.0cm (11¼ins)

22-24°C (71-75°F)

6.5-7.2.

Abdomen rounded. Four pairs of barbels. Rayed dorsal fin is absent with a short almost insignificant adipose fin. Pectoral fin with a slender spine serrated along inner edge. Pelvic fin small with 6 rays. The anal fin is very long and the caudal fin is deeply forked with the lower lobe longer. Lateral line is complete and simple.

Silvery, some of the fins tipped grey. Caudal fin often edged with a black tinge. Anal and caudal bases are slightly yellowish. Occiput often with black spots.

Nothing is documented in keeping A. coila in aquariums, but I would hazard a guess that it would be problamatic due to its predatory instincts.

As above.

It breeds in the shallow waters of the largest rivers with distinct pairing. It breeds during the monsoon season, from July to September. Fecundity ranges from 600-1300 eggs, and the pelagic eggs float in clusters.

Not recorded

It is carnivore but occasionaly feeds on algae, plant materials and debris.

Monotypic: Having only one species, such as a monotypic family of fishes.
Caudal fin: The tail.
Caudal peduncle: The narrow part of a fish's body to which the caudal or tail fin is attached.
Dorsal fin: The primary rayed fin(s) on top of the body.
Pectoral fins: The paired fins just behind the head.
Anal fin: The median, unpaired, ventrally located fin that lies behind the anus, usually on the posterior half of the fish.
Adipose fin: Fleshy finlike projection without rays, behind the rayed dorsal fin.
Lateral line: A sensory line, along the sides of the body.
Pelagic: Pertaining to the open water (large rivers/ocean).

Ailiia: Greek, aiolias, -ou = a fish (Scaridae)

Talwar, P.K. and A.G. Jhingran, 1991. Inland fishes of India and adjacent countries. Volume 2. A.A. Balkema, Rotterdam.
Froese, R. and D. Pauly. Editors. 2019.FishBase. World Wide Web electronic publication. www.fishbase.org, ( 02/2019 )
Ng, H.H. & Dahanukar, N. 2011. Ailia coila. The IUCN Red List of Threatened Species 2011
Jayaram. K.C. 2006, Catfishes of India. Narendera Publishing House. 383p.
Encyclopedia of Flora and Fauna of Bangladesh. Vol.23. Freshwater Fishes. Asiatic Society of Bangladesh. 300p.
www.mapsofindia.com: 2015.

Photo Credits

© Mostafa Hossain