Scientists solve Lefua loach puzzle

Scientists have completed a molecular study of endangered loaches in the Lefua genus to determine how they're interrelated.

Mihara, Sakai, Nakao, Martins, Hosoya and Miyazaki studied the nucleotide sequences of the mitochondrial DNA D-loop region of 100 fish collected from 97 different localities across Korea and Japan.

The genus, which currently contains three described species, L. costata, L. echigonia and L. nikkonis, and one undescribed one known simply as L. sp., is widely distributed around mountain ranges and various river systems, and the scientists believed that many of these species may include genetically distinct populations.

The team, who has just reported its finding in the journal Zoological Science, showed that all four species are distinct from each other, and that they do, indeed, include separate sub-populations which differ in their DNA.

The scientists said: "Lefua nikkonis was the most closely related to L. costata, while L. sp. was the most closely related to L. echigonia. Specimens of L. sp. were grouped into two intraspecific populations and specimens of L. echigonia were grouped into six populations.

"These populations were well separated geographically from one another by mountain ranges and highlands."

For more details see the paper: Mihara, M, T Sakai, K Nakao, LO Martins, K Hosoya and J-I Miyazaki, 2005. Phylogeography of loaches of the genus Lefua (Balitoridae, Cypriniformes) inferred from mitochondrial DNA sequences. Zoological Science, 22: 157-168.