Scientists find another tiny cyprinid

The genus to which the world's smallest fish species belongs now contains a third species, after a new one was discovered in Malaysia.

According to the New Straits Times, the tiny Paedocypris species was discovered by Amirrudin Ahmad of Kolej Universiti Sains Malaysia during a three-day expedition of Bukit Bauk in Terengganu, Malaysia. Like the other two members of the genus, the new discovery, which has yet to be described, is less than a centimetre in length making it one of the world's smallest vertebrate species.

Professor Datuk Dr Abdul Latiff Mohammad, who led the expedition, told the New Straits Times: "This discovery was the highlight of the Bukit Bauk expedition. We are confident this will attract biologists from around the world to do more research on the biodiversity of Bukit Bauk.

"There are still thousands of the fish in that peat swamp. My worry is that this habitat will end up like the one in Bukit Merah, disturbed by the construction of a road that killed all the specimens."

The Paedocypris genus, which was described earlier this year by Maurice Kottelat, Ralf Britz, Tan Heok Hui and Kai-Erik Witte currently contains two species - P. progenetica and P. micromegethes.

Paedocypris micromegethes was discovered near Kuching and Bukit Merah in 2001, while the second species (which is arguably the world's smallest fish) was found three years later in the peat swamps of Sumatra.

All of the fishes are adapted for life in threatened peat swamp environments and tolerate extreme conditions in which the water can as acidic as pH 3.0 - more than 1000 times more acidic than most of the UK's tapwater.

For more details on the Paedocypris genus see the paper: Maurice Kottelat, Ralf Britz, Tan Heok Hui and Kai-Erik Witte, 2006. Paedocypris, a new genus of Southeast Asian cyprinid fish with a remarkable sexual dimorphism, comprises the world's smallest vertebrate. Proc. R. Soc. B. doi:10.1098/rspb.2005.3419.