Barathronus affinis

The <em>Barathronus affinis</em> is a saltwater fish in the family Bythitidae, the viviparous brotulas — a group of deep-sea and cave-dwelling fishes notable for bearing live young rather than laying eggs. This species has been recorded at extreme depths, with documentation reaching down to approximately 2919 metres, placing it among the deepest-dwelling members of its family. No maximum body length data are currently available in the literature for this species. Bythitids exhibit remarkable adaptability to high-pressure, low-light, and often low-food environments. The viviparous reproductive strategy of the family, where females gestate embryos internally, is thought to be an adaptation that protects developing offspring from the harsh and predator-rich conditions of deep and cave environments. Details of habitat and range for this species remain limited in the ichthyological literature. The genus <em>Barathronus</em> is associated with deep oceanic floor habitats, and species in this group are rarely encountered due to the difficulty of sampling at bathyal and abyssal depths. <em>Barathronus affinis</em> is likely a benthic or benthopelagic predator, feeding on invertebrates and small organisms found near the seafloor. Systematic collections from deep-sea expeditions provide the primary basis for understanding the distribution of this species.