Common in the Solitary Islands Marine Park. Distributed throughout the Indo-Pacific region, from East Africa to the Johnston, Marquesas and Tuamoto Islands, north to Southern Japan, south to Australia. In Australia recorded around the north of the continent from Geraldton in Western Australia, the Coral Sea and Great Barrier Reef in Queensland south to the Victorian border on the east coast.
Frequents rocky reef and rubble areas, particularly sandy or silty pools or pockets. Depth to 10 m.
Mottled brown overall color, with five alternating irregular whitish and brown blotches or saddles dorsally on body, lower half of side with 5-7 rectangular brown blotches, white spots and blotches on cheek and operculum, see lower image. Intermediate stages, top image, difficult to identify and best recognised by presence of adults. Feed on polychaete worms and other small invertebrates. Specimens pictured in rockpool around 400 mm deep. Grow to 12 cm.
FishBase. Froese, R. and D. Pauly. Editors. 2018. World Wide Web electronic publication. https://www.fishbase.in/summary/Bathygobius-cocosensis.html. Accessed 23/04/2019.
Atlas of Living Australia website at https://bie.ala.org.au/search?q=Bathygobius+cocosensis. Accessed 23/04/2019.