NASO CAESIUS - (RANDALL & BELL, 1992)
Picture courtesy of: Yves Thévenet
Actinopterygii (Class) > Perciformes (Order) > Acanthuroidei (Suborder) > Acanthuridae (Family) > Naso (Genus)
Gray unicornfish, Silverblotched unicornfish, Silver-blotched unicorn, 藍灰鼻魚, تکشاخماهی خاکستری,
Dorsal spines (total): 6-7 (usually: 6); Dorsal soft rays (total): 27-30; Anal spines: 2; Anal soft rays: 28-31; Pectoral rays: 16-18; Body depth of subadults about: 2.2 in SL, of adults: 2.6-2.8; Two peduncular plates with knife-like keelsin adults; Caudal fin slightly emarginate to truncate. Max length: 45.6 cm SL. Depth range: 15 - 50 m.
Bluish grey to brownish grey dorsally, paler ventrally; No dark margin on operculum and preopercle; Capable of rapidly assuming a pattern of indistinct roundish to vertically elliptical blotches on upper half to tow-thirds of body which may be either darker or paler than ground colour; Tong not black.
Naso: from Latin, nasus = nose.
caesius: from Latin, caesius = bluish-gray. Named in reference to its most common ground color.
Original description: Naso caesius Randall & Bell, 1992 - Type locality: Northern side of East Channel, Eniwetak or Enewetak Atoll, Marshall Islands, western Pacific, depth 3-5 meters.
Western Pacific, antiequatorial: Micronesia and Marshall Islands east to Hawaiian Islands; Queensland (Australia) and New Caledonia east to Tonga, Society Islands and Pitcairn Group.
Inhabits clear oceanic waters along steep dropoffs, offshore reefs and pinnacles. Benthopelagic. Occurs singly or in aggregations. Feeds in midwater on zooplankton.
Naso caeruleacauda (Randall, 1994) - Reported from Western Pacific: east Indian region, Philippines, Papua New Guinea and Australia.
Naso hexacanthus (Bleeker, 1855) - Reported from New Caledonia - Link to the species (here).