Chaetodontidae
by T. Nalbant
Body deep, compressed, oval or subcircular. Head rhomboidal with large eyes; snout short, produced or extremely long. Preoperculum without a strong spine at angle but its hind margin feebly serrate or denticulate; lachrymal smooth to serrate; orbital rim smooth or denticulate; circumocular membrane sometimes with very small scales or papillae. Mouth generally small, terminal, protractile with 2-6 rows of circular teeth, their tips usually lanceolate; no teeth on vomer and palatines. Gill-slit large; opercular membrane developed, attached to the isthmus. Dorsal spines 6 16, generally strong with pointed tips; soft dorsal fin with 15-30 branched rays; anal fin usually with 3 spines, rarely 4 or 5 and with 14-25 branched rays; caudal fin always with 15 (8 + 7) branched rays; pelvic fins with a strong and pointed spine and 5 branched rays; pectoral fins usually with 12-15 branched rays. Body and head covered by ctenoid scales. Always an axillary scale at the base of pelvic fins. Lateral line incomplete, ending below the soft dorsal fin, or complete, reaching to the base of caudal fin. Presence offurca spinae supraoccipitalis, which comprises the first of the two free pterygiophores (or inter-neurals); sometime these two free pterygiophores may be fused. Size as adults: 70-300 mm in total length. Colour pattern complicated, with diverse-coloured crossbars or longitudinal bars; usually a dark brown or black crossbar across the eye; generally the colour pattern of juveniles is very different from those of adults.
Generally reef-dwellers, living from 1 to 20 m depth but a few species were observed down to 200 m. Feeding on algae or small invertebrates (polychaetes or small crustaceans); many species are coralfeeders. Very active during the day; many species have a marked territorial behaviour, hunting any intruder which penetrates their territory; therefore an aggressive behaviour is characteristic in these fishes; some species live in pairs, especially during the spawning period; others live in aggregations of 4-50 individuals, sometimes these aggregations may be formed by two species. No observations exist about their spawning or mating activities. All chaetodontids have a larval stage (Tholichthys stage) which is very different from the adults. The chaetodontids are marine circumtropical but a few species are temperate or even brackish water tolerant.
Genera 5; in Clofnam area 1.
Recent revisions: Nalbant (1973), Burgess (1978—monograph).