Ichthyologists Kevin Conway and Richard Mayden have described two new species of the cypriniform fish in the genus Psilorhynchus.
Naming them P. nepalensis and P. rahmani in a recent issue of the journal Ichthyological Exploration of Freshwaters, both species are distinguished from congeners by a combination of the number of lateral line scales and fin rays, absence of scales from its midventral region between the pectoral fins, colour pattern, and relative proportions of the head, snout and eye.
Psilorhynchus nepalensis, which is known from the Ganges River drainage in Nepal, is named after its country of origin (Nepal).
According to the authors, the type locality of this species is cool and swiftly flowing, with a gravel bottom and numerous riffles.
Psilorhynchus rahmani, named after Bangladeshi ichthyologist A. T. Ataur Rahman, is known only from the type locality, a small creek in the foothills of the Chittagong hill tracts in southeastern Bangladesh.
The water was clear to slightly turbid, with a moderate to fast current. There were numerous riffles, over a predominantly mud, sand/gravel, small boulder and slab rock substrate.
Psilorhynchus balitora, a species from the Ganges and Brahmaputra river drainages in Bangladesh and northeastern India, is also redescribed in this study.
For more information, see the paper: Conway, K. W. and R. L. Mayden (2008) Description of two new species of Psilorhynchus (Ostariophysi: Psilorhynchidae) and redescription of P. balitora. Ichthyological Exploration of Freshwaters 19: 215"232.