Snakeskin gourami (Trichopodus pectoralis) exhibits XX/XY sex determination and putative young Y chromosome shares sex chromosomal linkage homologies with those of amniotes

Snakeskin gourami (Trichopodus pectoralis) is one of the most common air-breathing freshwater fish of the Indochina peninsula. It has a high meat yield and is one of the top five aquaculture freshwater fish in Thailand. However, it takes 2–3 years for adults to reach sexual maturity. Snakeskin gourami is not externally sexually dimorphic and its sex determination remains unknown, complicating many aspects of broodstock management including sex manipulation. Understanding the sex determination system will contribute significantly towards full-scale commercialization. By  characterizing the sex determination system in snakeskin gourami using cytogenetic approaches and Diversity Arrays Technology, we identified sex-specific loci in 16 phenotypic sex assignments of snakeskin gourami. Of the 39 loci present in all males, 4 male-linked loci reached the criteria of moderately sex-linked loci (70:30; males:females and 80:20; males:females). By contrast, only one female-linked locus was detected...