''Apolemichthys trimaculatus'', the threespot angelfish or flagfin angelfish, is a

demersal The demersal zone is the part of the sea or ocean (or deep lake) consisting of the part of the water column near to (and significantly affected by) the seabed and the benthos. The demersal zone is just above the benthic zone and forms a laye ...

marine

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fishes, is a class of bony fish. They comprise over 50% of living vertebrate species. The ray-finned fishes are so called because their fins are webs of skin supported by bony or h ...

, a marine angelfish belonging to the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Pomacanthidae Marine angelfish are perciform fish of the family Pomacanthidae. They are found on shallow reefs in the tropical Atlantic, Indian, and mostly western Pacific Oceans. The family contains seven genera and about 86 species. They should not be conf ...

. It has a wide

Indo-Pacific The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...

distribution.

Description

''Apolemichthys trimaculatus'' is a bright yellow species of angelfish which has blue lips, a wide black margin to the

anal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as s ...

, a black spot on the forehead and a faint spot just to the rear of the operculum. The juveniles do not have the spots and show a thin black band running vertically through the eye and vertical golden barring on the flanks. The dorsal fin contains 14 spines and 16-18 soft rays while the anal fin has 3 spines and 17-19 soft rays. This species attains a maximum

total length Fish measurement is the measuring of individual fish and various parts of their anatomies. These data are used in many areas of ichthyology, including taxonomy and fisheries biology. Overall length * Standard length (SL) is the length of a fish ...

of .

Distribution

''Apolemichthys trimaculatus'' is widely distributed throughout the tropical waters of the

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by ...

from the coast of East Africa between Tanzania and Mozambique to the western

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the contine ...

where it reaches as Far East as Samoa, as far north as southern Japan and as far south as New Caledonia. In Australia it is found at

Ningaloo Reef The Ningaloo Coast is a World Heritage Site located in the north west coastal region of Western Australia. The heritage-listed area is located approximately north of Perth, along the East Indian Ocean. The distinctive Ningaloo Reef that fring ...

Rowley Shoals The Rowley Shoals is a group of three atoll-like coral reefs south of the Timor Sea, about west of Broome on the northwestern Australian coast, centered on , on the edge of one of the widest continental shelves in the world. Each atoll cov ...

and Scott Reef all in

Western Australia Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to ...

; Ashmore Reef in the

Timor Sea The Timor Sea ( id, Laut Timor, pt, Mar de Timor, tet, Tasi Mane or ) is a relatively shallow sea bounded to the north by the island of Timor, to the east by the Arafura Sea, and to the south by Australia. The sea contains a number of reefs, ...

and the

Great Barrier Reef The Great Barrier Reef is the world's largest coral reef system composed of over 2,900 individual reefs and 900 islands stretching for over over an area of approximately . The reef is located in the Coral Sea, off the coast of Queensland, ...

Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , established_ ...

Habitat and biology

''Apolemichthys trimaculatus'' is found at depths of where it lives on outer coral reef slopes and drop-offs. Here it feeds mainly on benthic invertebrates, mainly sponges and tunicates, although crustaceans are also taken. The juveniles are more secretive and solitary than the adults and typically remain deeper than . Adults are normally encountered at moderate depths in small, loosely organised groups. Threespot angelfish has a diurnal activity. It is

protogynous hermaphrodite Sequential hermaphroditism (called dichogamy in botany) is a type of hermaphroditism that occurs in many fish, gastropods, and plants. Sequential hermaphroditism occurs when the individual changes its sex at some point in its life. In particular ...

, which means the female can evolve to male during its life, and lives in harem composed of two to seven females for a male and it's a

territorial A territory is an area of land, sea, or space, particularly belonging or connected to a country, person, or animal. In international politics, a territory is usually either the total area from which a state may extract power resources or an ...

fish.

Systematics

''Apolemichthys trimaculatus'' Was first formally described as ''Holacanthus trimaculatus'' in 1831 by the

French French (french: français(e), link=no) may refer to: * Something of, from, or related to France ** French language, which originated in France, and its various dialects and accents ** French people, a nation and ethnic group identified with Franc ...

anatomist Anatomy () is the branch of biology concerned with the study of the structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old science, having it ...

Georges Cuvier (1769-1832) with the type locality given as the Molucca Islands.

Utilisation

''Apolemichthys trimaculatus'' is frequently found in the aquarium trade.

References

External links

* {{Taxonbar, from=Q2167851 trimaculatus Fish described in 1831 Taxa named by Georges Cuvier