Science News: Akysidae - Akysis in Indochina

[Silurus]

Synopsis by Shane Linder

In a recent article in the Journal of Natural History, Ng Heok Hee and Maurice Kottelat present their findings on the genus Akysis. The authors found six new species and divide the genus into two distinct groups. Members of the A. pseudobagarius group have a relatively elongate body, conspicuous subterminal mouths with the upper jaw overhanging the lower, and strongly forked caudal fins. Included in this group are A. alfredi, A. baramensis, A. fuscus, A. leucorhynchus, A. macronema, A. pseudobagarius, A. sinensis, A. similis, and A. subtilis. All other species of Akysis belong to the A. variegatus group.

The family Akysidae is known to hobbyists as the Asian banjo catfishes because of their remarkable resemblance to the South American family Aspredinidae. The authors also note that Akysis is sexually dimorphic and the males possess a genital papilla. In addition to the six new species below, A. leucorhynchus Fowler, 1934; A. hendricksoni Alfred, 1966; and A. maculipinnis Fowler, 1934 are discussed in the paper.

A. alfredi Ng & Kottelat, 1998 : Known from Tasek Bera in the southern Malay Peninsula.

A. similis Ng & Kottelat, 1998 : Known from the mouth of the Mekong basin in southern Vietnam.

A. subtilis Ng & Kottelat, 1998 : Known from the Mekong basin at Nakhon Phanom (northeastern Thailand), Luang Prabang and Tha Bo (Laos).

A. ephippifer Ng & Kottelat, 1998 : Known only from the lower Mekong basin in Cambodia.

A. recavus Ng & Kottelat, 1998 : Known from the western Chao Phraya basin, western Thailand.

A. varius Ng & Kottelat, 1998 : Known from the Mun basin at Nakhon Ratchasima, Ubon Ratchathani (central and eastern Thailand), the Siem Reap river in northwestern Cambodia, and the Xe Bangfai basin in western Laos.


Reference: Ng H. H. & M. Kottelat. 1998. The catfish genus Akysis, Bleeker ( Teleostei: Akysidae) in Indochina, with descriptions of six new species. Journal of Natural History, 1998, 32, 1057-1097.