Common Name
Spotfin Butterflyfish
Year Described
Bloch, 1787
Identification
Dorsal Fin: XII-XIII, 18-20
Anal Fin: III, 16-17
Pectoral Fin: 14-15
Lateral Line Scales: 33-39
Body oval, symmetrical and highly compressed. Snout short with a tiny terminal mouth. Slender teeth in jaws in several rows. Preopercular edge lacks spines. Dorsal spines not elongated. Soft dorsal and anal fin angular and lining up cleanly with caudal fin. Second anal spine longest. Caudal fin evenly rounded. Pelvic fins thin and almost reach anal fin origin. Pectoral fin under angle of opercle. Lateral line arched in front but incomplete. Axillary scale present. Body, head, and most of median fins scaled.
Color
Body bright white to bluish-white with an obvious black eyeband running from nape to bottom of opercular flap. Bright yellow on snout, on top edge of opercle, axil of pectoral fin, and all fins except pectoral fin. Variably expresses a black spot at the base of the soft dorsal fin and/or a small black spot near tip of soft dorsal fin. Thin black or blue stripes on distal part of caudal, dorsal and anal fins. Sleeping fish with a oblique dirty band across the body. Juveniles like a small version of adults but with a second black band on the rear body running from the dorsal fin to the anal fin. This marking shrinks with size into spots on the caudal peduncle and dorsal fin that can persist into adulthood.
Size
Maximum size to 20cm SL. Mature adults over 13cm SL.
Habitat
Coral reefs. Usually seen solitary or with a mate. Juveniles in seagrass or mangrove beds.
Range
Known from Florida to northeastern Brazil (islands), including the Gulf of Mexico and Caribbean Sea (rare around the islands). Vagrants north to Massachusetts and even Nova Scotia.
References
McEachran, J.D. and J.D. Fechhelm. 2005. Fishes of the Gulf of Mexico. Volume 2: Scorpaeniformes to Tetraodontiformes. University of Texas Press, Austin. i-viii +1-1004.