Stegastes planifrons

Family	Scientific Name	Author	Year	Common Name
Pomacentridae	Stegastes planifrons	(Cuvier)	1830	Threespot Damselfish

All Stegastes Species: Teeth in upper jaw conical or incisiform, but never flexible or brush-like. No notch in preorbital bone bordering the jaw. Dorsal-fin spines 14-17 and anal-fin soft rays 13-15. Suborbital and preopercle serrated (FAO 2002; FAO 2016).

Stegastes planifrons

Unique Characteristics: Dorsal-fin spines 12. Preopercle serrated. Purplish brown to brownish gray dorsally, yellow below. Always with large black spot at upper pectoral-fin base and on upper caudal peduncle. Upper rim of eye always yellowish. Snout may have a blue wash. Body comparatively deep.

Similar Species:

Stegastes adustus, Dusky Damselfish

Dusky Damselfish, Stegastes adustus. Dorsal-fin spines 12. Preopercle serrated. Body and fins dark bluish to purplish brown. Scale edges dark. May have faint blue spots on head, chest, and abdomen. Small, dark spot at upper pectoral-fin base. Soft dorsal- and anal-fin tips reach to or slightly beyond caudal-fin base.

Stegastes diencaeus, Longfin Damselfish

Longfin Damselfish, Stegastes diencaeus. Body deeply oval, compressed. 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; 10-11 lower gill rakers. A single continuous dorsal fin, XII, 14-17; anal fin II, 13; dorsal and anal fins long and rounded, reaching past base of tail fin; pectoral rays 19-21. No projecting short spines at upper and lower base of tail fin; caudal fin bluntly forked, lobes large and 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 19-20.

Adult: blackish to grey; snout, upper edge of eye-ball and nape with yellowish-brown cast; outer margin of anal fin with thin bright blue line. Juvenile: bright yellow body and fins; snout, nape and top of back grey-brown; 2 dotted blue lines along snout, top of head and upper back; a large black and blue ocellus at base of rear dorsal fin spines and upper body (https://biogeodb.stri.si.edu/caribbean/en/thefishes/species/3878).

Stegastes leucostictus, Beaugregory

Beaugregory, Stegastes leucostictus. Dorsal-fin spines 12. Preopercle serrated. Dark olive brown to dusky gray. May be pale below. Caudal fin yellowish to pale. May have blue spots on head and upper sides. Spot on caudal peduncle absent. Body comparatively shallow.

Stegastes partitus, Bicolor Damselfish

Bicolor Damselfish, Stegastes partitus. Dorsal-fin spines 12. Preopercle serrated. Several color phases exist: dark brown to blackish on anterior half to two-thirds of body with pearly posterior portion; dark brown to blackish on upper anterior portion of body, yellow below, with posterior portion pearly; overall pearly to grayish. Brownish black and yellow areas variable in size. Caudal fin may be pale to grayish. Pectoral fins always yellowish.

Stegastes variabilis, Cocoa Damselfish

Cocoa Damselfish, Stegastes variabilis. Dorsal-fin spines 12. Preopercle serrated. Dark bluish brown to greenish brown dorsally, yellow below. May have blue spots on head and upper body. Pectoral fins yellow. Rear portion of dorsal fin yellowish. Small spot at pectoral-fin base. May have a dark spot on upper caudal peduncle. Body comparatively deep.

References:

(FAO 2016). Carpenter, K.E. and N. De Angelis. eds. 2016. The living marine resources of the eastern central Atlantic. Volume 4: Bony fishes part 2 (Perciformes to Tetradontiformes) and sea turtles. FAO Species Identification Guide for Fishery Purposes, Rome, FAO. pp. 2343–3124.

(FAO 2002). Carpenter, K.E. ed. 2002. The living marine resources of the western central Atlantic. Volume 3: Bony fishes part 2 (Opistognathidae to Molidae), sea turtles and marine mammals. FAO Species Identification Guide for Fishery Purposes and American Society of Ichthyologists and Herpetologists. Special Publication No. 5. Rome, FAO. 2002. pp. 1375-2127.