Redeye goby (Bryaninops natans), is a species of marine fish in the family Gobiidae.
Short description - Dorsal spines (total): 5 - 9; Dorsal soft rays (total): 7-9; Anal spines: 1; Anal soft rays: 8 - 9. Dorsal-fin rays VI + I,7-1,9 (usually I,8); anal-fin rays I,8 or I,9 (usually I,9); pectoral-fin rays usually 14-16; scales on body extending forward at most to below interdorsal space, the longitudinal scale series 19-40 (mean count 31); canine tooth present on side of lower jaw; head and body compressed; body depth at origin of anal fin 16-25% SL; snout usually shorter than orbit diameter; gill opening reaching to or anterior to posterior margin of orbit; caudal fin usually slightly emarginate; pelvic fins forming a shallow cup, the spines as fleshy lobes; body transparent in life, except for yellow over abdomen; interorbital and iris bright pink. Largest specimen, 19.5mm SL.
Hovers in groups above branches of certain Acropora corals in shallow lagoon reefs.
Bryaninops natans is a marine, reef-associated species. The maximum total length for this species is 2.5 cm (Lieske and Meyers 1994). This species hovers in groups above branches of certain Acropora corals in shallow lagoon reefs (Kuiter and Tonozuka 2001). It is classified as a benthic spawner (Fishelson 1989). Given that this species probably lives to no more than 4 or 5 years, it is assumed that 3 generation lengths is likely less than 10 years (Larson pers. comm. 2017). This species also emits a strong red fluorescence around its eyes which is thought to be used to enhance visual communication (Michiels et al. 2008).
This species is dependent upon tall branching Acropora species habitat to depths of around 33 m within its range. More information is needed on the specific Acropora coral species this goby is primarily associated with, as well as how dependent it is on live coral. However, Acropora species within the Indo-West Pacific have declined on average, between 25 and 35% from the 1990's to 2010, with bleaching events increasing over the past 10 years (Wilkinson 2008, Hughes et al. 2018). This species is also harvested and sold in the aquarium trade (Burgess et al. 1990).