Actinopterygii (ray-finned fishes) > Perciformes
(Perch-likes) > Siganidae
Etymology: Siganus: Latin, siganus = a fish, rabbit fish; by the similarity of the nose (Ref. 45335).
Environment / Climate / Range
Marine; reef-associated; depth range 0 - 25 m (Ref. 90102), usually 0 - 20 m (Ref. 27115). Tropical; 25°C - 29°C (Ref. 27115), preferred ?; 25°N - 30°S, 75°E - 175°E
Indo-West Pacific: Maldives, Laccadive Archipelago, India, Sri Lanka, Ogasawara Islands (Japan), eastern Indonesia, New Guinea, Australia, Solomon Islands, Vanuatu, New Caledonia and Philippines; Palau and Yap in Micronesia. Records from Viet Nam (Ref. 2682) is probably Siganus guttatus.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 43.0 cm TL male/unsexed; (Ref. 9710); common length : 25.0 cm TL male/unsexed; (Ref. 9813)
soft rays: 9;
Vertebrae: 13. Blue dorsally, silvery below; a bright yellow spot below last few rays of dorsal fin; a prominent blue line beside posterior margin of orbit running diagonally across cheek to corner of mouth. Preopercular angle 92°-104°; strong scales almost completely cover cheeks; midline of thorax scaled, not pelvic ridges. Anterior nostril encircled by a very low rim, slightly expanded posteriorly. Spines stout, pungent and venomous (Ref. 1419).
Juveniles found in mangrove areas and seagrass flats; adults in protected waters such as lagoons and bays in the vicinity of rocky substrata or reefs. Forms schools that diminish with age, down to 10-25 fish by adult stage, although congregations may consist of several thousand fish during spawning period. Feeds by scraping encrusting algae from beach rock or pavement areas of coral reefs or by browsing on larger coarse algae. Common in markets where it is sold fresh (Ref. 9813).
Smallest female to spawn was 23 cm, the largest 33 cm SL. Spawning apparently occurs not until the fish is 2 years old.
Woodland, D.J., 1990. Revision of the fish family Siganidae with descriptions of two new species and comments on distribution and biology. Indo-Pac. Fish. (19):136 p. (Ref. 1419)
IUCN Red List Status (Ref. 109396)
CITES (Ref. 94142)
Fisheries: commercial; aquarium: commercial
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingMass conversion
Estimates of some properties based on models
Phylogenetic diversity index (Ref. 82805
= 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.01738 (0.01072 - 0.02817), b=2.99 (2.85 - 3.13), based on LWR estimates for this species & Genus-body shape (Ref. 93245
Trophic Level (Ref. 69278
): 2.0 ±0.00 se; Based on food items.
Resilience (Ref. 69278
): High, minimum population doubling time less than 15 months (K=0.6; tm=2).
Vulnerability (Ref. 59153
): Low to moderate vulnerability (25 of 100) .