Sigan pintade, Net-pattern spinfoot, Pearlspotted spinefoot, Pearly spinefoot, Seagrass rabbitfish, Slimy spinefoot, Smudgepot spinefoot, White spotted rabbit fish, White-spotted rabbitfish, White-spotted spinefoot, Whitespotted rabbitfish, Whitespotted spinefoot, Sigano pintado, Safi arabi, Hvidplettet kaninfisk, Shimofuri-aigo, シモフリアイゴ, 관독가시치, 长鳍篮子鱼, 象鱼, สลิดทะเลจุดขาว,

Synonymes
Amphacanthus dorsalis (Valenciennes, 1835)
Amphacanthus guttatus oramin (Bloch & Schneider, 1801)
Chaetodon canaliculatus (Park, 1797)
Siganus oramin (Bloch & Schneider, 1801)
Teuthis dorsalis (Valenciennes, 1835)
Teuthis oramin (Bloch & Schneider, 1801)
Theutis dorsalis (Valenciennes, 1835)

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Description

Dorsal spines (total): 13; Dorsal soft rays (total): 10; Anal spines: 7; Anal soft rays: 9; Pectoral fin rays: 17-18; Pelvic fin rays: I, 3, I - Pelvic fins with two spines (1 strong inner and 1 outer spine, with 3 soft rays in between); Scales row above lateral line: 16-27 between lateral line and bases of dorsal-fin spines 2-4; Scales minute; Cheeks scaleless, or with few to many very fine scales; No scales along midline of thorax. Body compressed moderately slender, its depth: 2.3-2.8 in SL; Head profile slightly to markedly concave above eye: 4.7-4.9 in SL; Snout pointed rather than blunt; Fourth to seventh dorsal-fin spine longest, much longer than (1.7-2.2 times) the last; Last anal-fin spine: 1.2-1.5 times in longest anal-fin spine (usually the third); Soft parts of dorsal and anal fins low, longest dorsal-fin ray: 0.7-1.0 times in longest dorsal-fin spine; Caudal fin almost emarginate in specimens under 10 cm standard length, forked in larger fish (but median rays never less than 1/2 length of longest rays); A forward-directed spine present in front of dorsal fin; Anterior nostril with a long flap in juveniles, shortening with age, absent in old fish; Nostril flap reaching less than half-way to posterior nostril in specimens larger than 12 cm in SL. Max. length: 35.0 cm TL, common length: 20.0 cm TL. Depth range: 3 - 40 m.

Color
Color pattern in life variable, influenced by habitat, age and mood of fish. Head and body silvery grey above, with trace of green on nape, and silver below; ~100-250 pearly round, ovoid and rod-shaped spots evenly dispersed over each side of body, tiny on nape and larger elsewhere, arranged in more or less regular rows, 2-4 rows of spots above lateral line. Frightened fish entirely mottled with shades of pale and dark brown, but mainly 5-6 darker diagonal zones alternating with paler zones across sides, obscuring regular pattern of spots.

Etymology
Siganus: Latin transformation of the Arabic word, sijān = a fish, rabbit fish. Referring to the similarity of the nose.
canaliculatus: from Latin, canāliculus = like a channel or pipe, channelled, grooved. Park described fin spines as canaliculate, probably referring to anterolateral grooves along dorsal- and anal-fin spines (which Park did not know contain venom glands, common to all rabbitfishes).
Original description: Chaetodon canaliculatus Park, 1797 - Type locality: Bengkulu Province, Sumatra, Indonesia, eastern Indian Ocean.

Distribution
Indo-West Pacific: Persian Gulf east to Palau, Yap and New Ireland (Papua New Guinea), north to Ryukyu Islands (Japan), south to northern Australia and New Caledonia.

Biology
Inhabit inshore, algae reefs, estuaries and in large lagoons with algae-rubble habitats. Mainly common on rocky substrates. This species seems to tolerate more turbid waters, occurring within the vicinity of river mouths especially around seagrass beds. Adults also occur several kilometers offshore in deep, clear waters. Juveniles form very large schools in shallow bays and coral reef flats; School size reduces with size, with adults occurring in groups of 20 individuals or so. Herbivorous, feed on benthic algae and to some extent on seagrass. Consumed as food; Have poisonous spines. Multiple spawner. Larger fish may spawn more than once in a spawning season. Spawn in group.

Similar species

• Siganus argenteus (Quoy & Gaimard, 1825) - Reported from New Caledonia - Link to the species (here).
• Siganus fuscescens (Houttuyn, 1782) - Reported from New Caledonia. Differs by its slightly more pointed snout and longer pectoral fins (1.1-1.3 in HL vs. 1.4-1.5 in Siganus fuscescens). Siganus fuscescens don't show dots on snout and nape.
• Siganus margaritiferus (Valenciennes, 1835) - Reported from Eastern Indian Ocean, western Pacific: Andaman Islands to Solomon Islands, north to Japan, south to northern Australia. Caudal in the shape of crescent with the pointed lobes. Back dirty greenish, flanks grayish which passes on the belly to the dull white, slightly silvered. All its body is strewn with bluish points; The dorsal and the caudal are of a dark greenish; The pectoral are greenish yellow.
• Siganus sutor (Valenciennes, 1835) - Reported from Indian Ocean: East Africa, South Africa, Golf of Aden, Socotra, Seychelles, Madagascar and Mascarenes east to Myanmar and Bali (Indonesia).
• Siganus vermiculatus (Valenciennes, 1835) - Reported from Eastern Indian Ocean, western Pacific: India, Bangladesh and Sri Lanka east to Micronesia and Fiji.
• Siganus woodlandi (Randall & Kulbicki, 2005) - Reported from New Caledonia - Link to the species (here).

Last update: 4, April 2023