Genetic analysis of Gobiopterus brachyopterus (Oxudercidae) from Grati Lake and The genus potential misidentification.

The holotype of Gobiopterus brachyopterus originates from Grati Lake, Indonesia. It is locally called lempuk fish. The genus Gobiopterus has similar species, making identification difficult. A genetic study using the COI region revealed possible misidentification issues. Phylogenetic analysis showed that populations in India and Brunei are separate species. These populations formed distinct clades from the Grati Lake population. Genetic P-distance supported this, with a 21.7% difference for India and 21.9% for Brunei. A haplotype network confirmed the Grati Lake population's uniqueness. It is genetically closer to Gobiopterus lacustris than to Indian or Brunei populations. G. brachyopterus was found to be genetically endemic to Grati Lake.