Australian scientists have found evidence for a second species of barramundi or Asian sea bass (Lates calcarifer) using DNA barcoding.
The results are reported by Robert Ward, Bronwyn Holmes and Gordon Yearsley in the latest issue of the Journal of Fish Biology.
By sequencing and analysing an approximately 650 base pair (bp) region of the mitochondrial cytochrome c oxidase I gene (DNA barcoding), the authors found a deeply divergent (9.5%) clade comprising of specimens from Australia and Singapore on one hand and a single specimen from Myanmar on the other.
This was supported by a further analysis of a 306 bp region of the cytochrome b gene,which found a cluster of L. calcarifer from Malaysia, Singapore and Australia (18% within group divergence) that is again deeply divergent from the (single) specimen from Myanmar (113% divergence).
Given that Nile perch (Lates niloticus) were about 19% divergent from all populations of barramundi studied, the authors conclude that there is possibly a second species of barramundi.
However, they cautioned that their results ...needs to be validated by further taxonomic work, including detailed morphological and meristic comparisons. In addition, careful examination and redescription of specimens through the currently recognized range of L. calcarifer is recommended to determine the number of species and their appropriate scientific names.
For more information, see the paper: Ward, RD, BH Holmes and GK Yearsley (2008) DNA barcoding reveals a likely second species of Asian sea bass (barramundi) (Lates calcarifer). Journal of Fish Biology 72, pp. 458"463.