A new freshwater fish species has been described in the scientific journal Zootaxa. Found in Sabah state it is now one of five endemic Betta species, and one of 700 known fish species on the island of Borneo, half of which occur nowhere else on earth.
Its name “nuluhon” means hill in the Dusun language and its so-called because of the clear, shallow, hillstream habitat its found in.
It is part of the Betta akarensis group and is allied to both B. chini and B. balunga, but differs from the rest of its congeners in having a yellow iris, greenish-blue iridescence on the opercle of mature males, distinct transverse bars on the caudal fin, a slender body, faint reticulate pattern and an absence of tiny black spots on the anal fin.
The Sabah Forestry Department said its research officer Nur Syafiqah Shamsul Kamal had worked in collaboration with the National University of Singapore (NUS) and local NGO, Forever Sabah, in classifying the fish.
NUS tropical fish taxonomist Dr Tan Heok Hui who co-authored the recent Zootaxa publication said he expected several more new species to be discovered in Sabah soon under his collaborative work with the Forest Research Centre of the Sabah Forestry Department.
Previously a publication back in 2017 claimed some parts of Sabah, particularly the southernmost parts of the state, remained poorly explored and sampled for fish diversity, paving an opportunity for more work to be done.
To date, some 70 wild species of fighting fish have been scientifically identified.