Scientists have described two more species of the Asian catfish genus Akysis.
Publishing their results in the latest issue of the journal Copeia, Lawrence Page, Renny Hadiaty, J Andres Lpez, Ike Rachmatike and Robert Robins have described Akysis scorteus from the Way Seputih drainage and Akysis galeatus from the Way Sekampung drainage, both in southern Sumatra.
Akysis scorteus is named after the leathery skin of the genus (scorteus means made of leather) and A. galeatus after the bony ridges on the head (galeatus means helmeted).
The two species resemble each other most closely, but can be distinguished by the sculpturing on top of the head:
"In A. galeatus, the top of the head is distinctly concave medially, and the concavity is bordered on either side by a ridge that originates between the nasal barbels and extends to the elevated supraoccipital process....In A. scorteus, the top of the head is flat and lacks conspicuous concavity or bony ridges.
Akysis scorteus further differs from congeners in having a combination of emarginate caudal fin, colour pattern of irregular brown bands on a yellow body, and three small serrations on the pectoral spine.
Akysis galeatus further differs from congeners in having a combination of emarginate caudal fin, colour pattern of irregular brown bands on a yellow body, and one to three small serrations on the pectoral spine.
The study also redescribes A. variegatus, a poorly-known species from Java.
There are 17 species of Akysis, of which only one other species, A. heterurus, is known from Sumatra.
For more information, see the paper: Page, LM, RK Hadiaty, JA Lpez, I. Rachmatika and RH Robins (2007) Two new species of the Akysis variegatus species group (Siluriformes: Akysidae) from southern Sumatra and a redescription of Akysis variegatus Bleeker, 1846. Copeia 2007 (2), 292"303.