Species: Stegastes xanthurus, Cocoa Damselfish

Stegastes xanthurus (Poey, 1860)

Cocoa Damselfish

Body moderately deep, oblong, compressed; snout angular; 1 pair of nostrils; margin of preopercle serrated; margin of bone under eye serrated, without notch between it and the bone before it; mouth small, protrusible, opens at front; teeth in single row, long and close-set incisors; 8-9 lower gill rakers; a single continuous dorsal fin, XII, 14-17; anal fin II, 12-15; dorsal and anal fins long, extend past tail fin base, with large lobes; pectoral rays 18-21; no projecting short spines at upper and lower base of tail fin; caudal fin bluntly forked, lobes of tail bluntly rounded; scales are moderately large and rough; body scaled, head largely scaled (snout scaled to nostrils), as are the basal parts of the median fins; lateral line incomplete, ends under end of dorsal fin base; lateral-line scales 18-20.

Adult variable and with intergrading patterns: 1. Entire head, body and fins grey-brown, with yellowish tint to tail fin belly and anal and pectoral fins; dark edges to scales form oblique lines on body; often a large black spot on last dorsal fin spines and upper back, and another smaller one on upper tail base. 2. Intermediate between pattern 1 and juvenile. Juvenile: upper head and back and front 2/3 of dorsal fin dark grey-brown overlaid densely with evenly distributed blue spots, remainder of body and fins lemon yellow; blue lines along snout and through eye run along upper back; dark edges of scales of upper body form oblique dark lines running down body; a large black ocellus on base of last few spines of dorsal fin, which extends onto the upper body; usually a black spot on the upper tail base.

Size: reaches 12 cm.

Sheltered reef habitats.

Depth: 0-100 m.

N Carolina to the S Caribbean.

Note: S. xanthurus, which was described from Cuban specimens in 1860, has been considered to be a synonym of Stegastes variabilis which was described from Brazilian specimens in 1855. However, the Caribbean and Brazilian populations are genetically very distinct; hence we use the earliest name available for the Caribbean species.