Antennatus coccineus is another variable frogfish, although at Kwajalein we have seen them mostly in red and yellow, and all much smaller than the reported maximum size. Three different red specimens are figured on this page. This species can be very difficult to distinguish from the also variable Antennatus nummifer. One of the few characters of external morphology that consistently separate the two species is that the posterior dorsal and anal fins in A. coccineus extend all the way to the beginning of the tail fin, while in A. nummifer, there is a section bare of fins at the caudal peduncle. Since you have to have just the right photo to see this feature, it is easier to determine species if you can examine the real fish. The first photo below was confimred as A. coccineus by a leading expert in the field. That animal measured about 30mm and was hidden in a lagoon Halimeda patch at a depth of about 10m.
The smaller specimen below was under a rock on a Kwajalein Atoll seaward reef.
The tiny one below was in a lagoon Halimeda patch.
Created 10 September 2016
Updated 26 December 2019