Scientists have described a new species of hillstream loach from the genus Erromyzon.
David Neely, Kevin Conway and Richard Mayden discovered the new species while studying preserved specimens at Kunming Institute of Zoology which had been identified as "Protomyzon" pachychilus.
The species, which is a member of the Balitoridae family and originates from the Pearl River (Zhu Jiang) drainage of the Guangxi Province in China, and has been named Erromyzon yangi in a paper in the latest issue of the journal Ichthyological Exploration of Freshwaters.
Neely, Conway and Mayden said that the new Erromyzon can be told apart from other members of the genus by the following combination of characters: "a uniformly coloured dorsum (vs. dorsum with dark vertical bars); a narrow median lobe between the anterior barbels (vs. broad median rostral fold); and a higher number of lateral line pores (96-99 vs. 83-86).
The new species is found at the same type locality as "Protomyzon" pachyphilus and Erromyzon sinensis. But the three fish can be distinguished by differences in colouration, as well as morphomeristic features: "P." pachyphilus has irregular blotches along the flanks, while E. sinensis has dark vertical bars which are clearly visible from the dorsal surface.
The species was named Erromyzon yangi in honour of Yang Jun-Xing, the Deputy Director of the Kunming Institute of Zoology.
The fish is a member of the Gastromyzontini group of balitorids, which are endemic to east and south east Asia. The type specimens measure around 3-4cm in length and were caught at an elevation of 624m above sea level.
For more information see the paper: Neely DA, Conway KW and RL Mayden (2007) - Erromyzon yangi, a new hillstream loach (Teleostei: Balitoridae) from the Pearl River drainage of Guangxi Province, China. Ichthyological Exploration of Freshwaters.