Scarus rivulatus Valenciennes, 1840
Rivulated parrotfish
photo by Cook, D.C.

Family:  Scaridae (Parrotfishes), subfamily: Scarinae
Max. size:  40 cm SL (male/unsexed)
Environment:  reef-associated; marine; depth range 1 - 30 m
Distribution:  Western Pacific: Thailand to New Caledonia, north to the Ryukyu Islands, south to Perth and New South Wales in Australia. Recently recorded from Tonga (Ref. 53797).
Diagnosis:  Dorsal spines (total): 9-9; Dorsal soft rays (total): 10-10; Anal spines: 3-3; Anal soft rays: 9-9. This species is distinguished by the following features: 5-7 (usually 6) median predorsal scales; 3 scale rows on cheek 1(5-7), 2(5-7), 3(1-4); pectoral-fin rays 13-15 (usually 14); conical teeth on side of dental plate, none in female and usually 2 on upper and 0-1 on lower of dental plates for terminal male; lips nearly covering dental plates; caudal fin slightly rounded to truncate in female and emarginate in terminal male. Colour of patch covering cheek and gill cover of male orange, wavy band/lines on snout and cheek, pectoral fins pale green; female grey or grey-brown with 2 pale stripes on belly (Ref. 9793, 90102).
Biology:  Found in silty coastal and offshore areas to 20 m deep (Ref. 90102). Inhabits rocky and coral reefs from tidal pools to at least 10 m deep. Form schools with 30 to 40 individuals. Grazes on benthic algae and corals (Ref. 2935). Reproductively active terminal males become bicolored (Ref. 37816).
IUCN Red List Status: Least Concern (LC); Date assessed: 18 September 2009 Ref. (130435)
Threat to humans:  harmless


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