Indian scientists have described a new species in the South Asian cypriniform genus Psilorhynchus.
Publishing their results in a recent issue of the journal Current Science, Arunachalam, Muralidharan and Sivakumar describe Psilorhynchus amplicephalus from the Barak River drainage (itself part of the Brahmaputra River drainage) in Assam, northeastern India.
The species is named after its broad head (ampli = broad; cephalus = head).
According to the authors: "The new species can be easily diagnosed by the spindle-shaped, subcylindrical body and anteriorly compressed head.
"Further, it can be identified by features like scale-less abdomen, horizontally placed pectoral and pelvic fins and also by the presence of 35"36 scales along the lateral line series.
"These fishes have dark brownish spots in the predorsal region and also along the sides of the body. The relatively bigger head, deeper body and smaller mouth distinguish it from other species of this genus.
"A hump-like shape found in the predorsal region of bigger specimens is also a distinct feature that has not been reported in any other species."
There are currently seven other species of Psilorhynchus recognized: P. arunachalensis, P. gracilis and P. homaloptera from the Brahmaputra River drainage, P. balitora, P. pseudecheneis and P. sucatio from the Ganges-Brahmaputra river system, and P. microphthalmus from the Irrawaddy River drainage.
For more information, see the paper: Arunachalam, M, M Muralidharan and P Sivakumar (2007) Psilorhynchus amplicephalus, a new species from Balishwar river of Assam, India. Current Science 92, 1352"1354.