Stegastes xanthurus

Lore & Background

The genus name Stegastes is Greek for stegastos, meaning covered. This species was formerly considered conspecific with the Brazilian cocoa damselfish. The Caribbean cocoa damselfish is an oval, laterally compressed fish. The top of the head and snout bear several blue stripes, and the top half of the body is generally dark blue or brown while the bottom half is yellow. The sides are finely barred with vertical dark lines, and there are two small black spots: one above the pectoral fins and the other on the top of the caudal peduncle. The large dorsal fin has 12 spines and 14 to 17 soft rays; the anal fin has two spines and 12 to 15 soft rays; and the caudal fin is shallowly forked with rounded lobes.

Juveniles have tiny blue spots and stripes on the head and upper body, including two spots and a stripe on the upper iris, and a dusky blue sheen. A blue-rimmed black eyespot is located where the dorsal fin spines join the soft rays, and a similar spot is found at the top of the caudal peduncle. Older juveniles develop the characteristic blue and yellow coloration of the adult. The species is found from the Florida Keys and the Gulf of Mexico to northern South America, common on offshore reefs, oil platforms, and wrecks, with juveniles occasionally appearing inshore.

Reader's Guide

The Caribbean cocoa damselfish is significant as a commercial aquarium fish due to its size and colorfulness. In the wild, individuals do not overlap territories with other damselfish. They appear to survive longer in captivity, up to 18 years, whereas they do not live beyond 12 years in the wild. During the breeding season, females lay eggs on the seabed attached to empty shells, stones, or other objects, and the male fertilizes them, then guards, aerates, and chases away intruders for seven days. Most communication between this species occurs during breeding season. The species was formerly considered conspecific with the Brazilian cocoa damselfish, reflecting taxonomic uncertainty. Its distribution in the western central Atlantic includes the Florida Keys, Gulf of Mexico, and northern South America, and it is associated with marine reefs, oil platforms, and wrecks.

Did You Know?

• Males guard and aerate the eggs for seven days after fertilization.
• They can live up to 18 years in captivity but not beyond 12 years in the wild.