Scientists have described a new species of leaf fish from Sabah in north eastern Borneo.
The new member of the family Nandidae has been named Nandus prolixus by Prosanta Chakrabarty, Ronald Oldfield and Heok Hee Ng in a paper in the latest issue of the systematics journal Zootaxa.
The north east of Borneo is an area of endemism for many fish species and several apparently widespread fish species found here have been shown to be distinct species when studied in greater detail.
The team found that the fish previously believed to be Nandus nebulosus in the Sepilok River drainage in Sabah was in fact an undescribed fish, which they named N. prolixus.
Nandus prolixus has a longer, more produced snout than N. nebulosus and more scales in the lateral line series, with 33-37 in prolixus compared to 24-34 in nebulosus, and also has more scales below the lateral line, with 12 rather than the 10-11 seen in nebulosus.
The species is believed to be confined to north eastern Borneo's Sepilok River drainage, however, the authors believe that specimens of N. nebulosus collected from the Kinabatangan River drainage in southern Borneo by Inger and Chan in 1962 may have also been prolixus.
The species is believed to occur in very slow-moving shallow streams in swampy forested areas where they live among fallen leaves and tree roots.
For more information see the paper: Chakrabarty P, Oldfield R and Ng HH (2006) - Nandus prolixus, a new species of leaf fish from northeastern Borneo (Teleostei: Perciformes: Nandidae). Zootaxa 1328: 51-61 (2006).