Filambase

The gregarious humphead parrotfish is always found in small shoals, sometimes consisting of up to 75 individuals (1). It feeds on a diet of live corals and algae that grow on the ocean bottom, and uses its large bulbous head to ram the coral to break it into smaller, more easily digested pieces (1). Its beak-like front teeth and pharyngeal teeth at the back of the throat adeptly grind down this food, reducing the hard coral to a paste and breaking down the algae (3). Any hard, un-nutritious material is passed out in the fish's faeces (3). As a consequence, adult humphead parrotfish, which are estimated to consume five to six tonnes of coral each year, produce substantial amounts of sediment and influence the structure of coral reefs, thus playing an important role in the coral reef ecosystem (2). Humphead parrotfish aggregate to spawn at a certain time each month, often around the time of the full moon, in reef channels and passages. Spawning often takes place in early morning (2) (5), when females release eggs to be fertilized in the water by the sperm released by the male. These large spawning aggregations may consist of around 100 individuals. Large groups of humphead parrotfish are also found when they are sleeping. These large fish can live to an age of at least 40 years (1).

There are no protective measures specifically in place for the humphead parrotfish (1), but a number of fishing regulations should afford this vulnerable fish some protection (2). For example, in some regions, restrictions on night-time spear-fishing or spear-fishing with compressed air are in place (1) (2), measures which will help protect the parrotfish when it is at its most vulnerable. Marine Protected Areas (MPAs), in which fishing is prohibited, protects numerous species; two MPAs were established in the Solomon Islands in 2002 (Baraulu Village and Nusa Hope Village) to protect the humphead parrotfish and other reef species (1).

The largest of all parrotfish, the humphead parrotfish is an olive or blue-green to slate-grey fish, with a yellowish to pink head (2). Its most distinctive feature, and the reason for its common name, is the prominent bulbous forehead which develops in adults (2). Juvenile humphead parrotfish do not have this bulging head and also differ slightly in colour, being green or brown with five vertical rows of small, whitish spots (2). Parrotfish get their name from their peculiar teeth, which are fused into a parrot-like beak. They also have teeth at the back of the throat which grind food (3).

This coral reef fish inhabits shallow fringing and barrier reefs, between depths of one and thirty metres (1) (2). While adult parrotfish are most often found in outer lagoons and seaward reefs, juveniles are more often found inside lagoons, in seagrass beds (4). At night, this parrotfish can be found resting in caves or on the sandy flats of shallow lagoons (2).

The humphead parrotfish can be found in tropical and subtropical coral reefs in the central and western Pacific, Indian Ocean and Red Sea (2).

Classified as Vulnerable (VU) on the IUCN Red List 2007 (1).

The habit of feeding, resting and spawning in groups makes the humphead parrotfish highly vulnerable to fishing, particularly by spear-fishing during the night (1) (2). This has resulted in a decline in numbers of the humphead parrotfish in some areas (1), and this once abundant fish is now virtually extinct in Guam, the Marshall Islands, parts of Fiji and East Africa (2).

Occur inshore (Ref. 75154). Juveniles found in lagoons; adults in clear outer lagoon and seaward reefs up to depths of at least 30 m (Ref. 9710). Sleeps in caves and often in shipwrecks at night (Ref. 48636). Usually in small groups and feeds on benthic algae, live corals (Ref. 9710) and shellfishes (Ref. 58784). May ram its head against corals to facilitate feeding. The largest and wariest of the parrotfishes (Ref. 9710).

Dorsal spines (total): 9; Dorsal soft rays (total): 10; Analspines: 3; Analsoft rays: 9

This species is distinguished by the following characters: median predorsal scales 2-4 (may be obscured by hump); 3 scale rows on cheek, 1 (4-6), 2 (3-6), 3 (1-2); pectoral-fin rays 16 or 17; steep profile distinctive; nodules on teeth unique (Ref. 9793); prominent bump on forehead of adult (evident at least 25 cm TL); deep body 2.0-2.5 in SL, with depth increasing with growth; Colour of juveniles brownish to green with 5 vertical rows of whitish spots on side, the primary phase is a dull gray with scattered white spots, gradually becoming uniformly dark green (Ref. 90102, 1602).

Oviparous, distinct pairing during breeding (Ref. 205). Also Ref. 103751.

Juveniles are found in lagoons while adults inhabit clear outer lagoon and seaward reefs up to depths of at least 30 m (Ref. 9710). They ‘sleep’ in caves and often in shipwrecks at night (Ref. 48636). They are usually in small groups feeding on benthic algae, live corals (Ref. 9710) and shellfishes (Ref. 58784). They sometimes ram their head against corals to facilitate feeding (Ref. 9710). The largest and wariest of the parrotfishes. Assessments showed their vulnerability to overfishing (Ref. 9710).

fisheries: commercial; aquarium: commercial

分布於印度-太平洋區海域，西起紅海及東非，東至美屬薩摩亞及萊恩群島，北至日本八重山與維克群島，南至澳洲大堡礁與新加勒多尼亞。台灣東部、南部、澎湖、綠島及蘭嶼海域均有分布。

主要捕獲的漁法是延繩釣、一支釣、流刺網及籠具等，而本種魚亦是潛水鏢魚的對象以及水族館展示魚種。是鸚哥魚中最大型的魚種，全年皆有產，以夏季較多。由於捕撈過度是應受保育的魚種。

體延長而略側扁。體長約25公分左右時，頭部前額即向前突出，頭部輪廓可近於垂直角度。後鼻孔明顯的大於前鼻孔。齒板之外表面有顆粒狀突起；每一上咽骨具3列臼齒狀之咽頭齒，其後列者並不發達 。背鰭前中線鱗約2-5(通常為4)；頰鱗3列，鱗片大型，最下方列具鱗1-2個；間鰓蓋具1列鱗。鰓耙數16-18。胸鰭具15-16軟條；尾鰭於幼魚時圓形，成體時則略呈雙凹形。初期階段(IP, Initial phase)體呈暗灰色，體側散在白色斑點，至終期階段(TP, Terminal phase)逐漸地變成全深綠色至綠褐色，沿著體側之鱗列，分布淺紫色之條紋；頭部的前緣時常是淡綠色到粉紅色；各鰭之顏色同與體色。

稚魚發現於潟湖；成魚則群游於礁灣或珊瑚礁外圍的海域。以啃食活珊瑚為食。生性機警，在夜間有群體一起睡覺的習性。

Occur in schools on clear outer lagoon and seaward reefs at depths of 1 to at least 30 m. Usually in small groups. Feeds on benthic algae and live corals. The largest and wariest of the parrotfishes.