''Pomacanthus navarchus'', the blue-girdled angelfish or majestic angelfish, is a

marine angelfish 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 confu ...

from the

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 ...

region. It occasionally makes its way into the aquarium trade. ''P. navarchus'' is one of the smallest of the larger

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of angelfish. It grows to a maximum length of , but is usually much smaller than this, and can live to be up to 21 years old. Younger fish stay closer to the shallows, but the more mature fish can be found up to deep. Majestic angelfish eat mainly sponges and

tunicate A tunicate is a marine invertebrate animal, a member of the subphylum Tunicata (). It is part of the Chordata, a phylum which includes all animals with dorsal nerve cords and notochords (including vertebrates). The subphylum was at one time ca ...

Juvenile fish Fish go through various life stages between fertilization and adulthood. The life of a fish start as spawned eggs which hatch into immotile larvae. These larval hatchlings are not yet capable of feeding themselves and carry a yolk sac which ...

are mostly blue in color with white stripes. As they mature, they take on a yellow coloration on the flanks, dorsal fin, and tail.

Description

The body of this fish is laterally flattened. Adult fish have three main colored sections; the anterior section in front of the eyes and the front part of the body is lemon yellow; the central section is funnel-shaped and is deep blue, and the posterior section is reticulated in bright yellow and blue. The sections are separated by pale blue bands edged with black. The mouth and lips are blue as are the rays of the pectoral and anal fins, while the dorsal and caudal fins are yellow, edged with pale blue. There is a long spine on the gill cover which is used in defence. Juvenile fish are dark blue with slightly curved, white lateral stripes. The change from the juvenile to the adult coloring takes place quite abruptly, with little intermediate coloring.

Distribution and habitat

''Pomacanthus navarchus'' is native to the tropical Indo-Pacific region, its range extending from Indonesia and the Philippines to northern and eastern Australia and Micronesia. It can be found at depths down to about on outer reef slopes, channels and lagoons in coral-rich habitats.

Ecology

''Pomacanthus navarchus'' is territorial and is generally found alone, but occasionally in pairs or small groups. It inhabits the

demersal zone 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 layer of ...

, feeding on sponges, algae,

zooplankton Zooplankton are the animal component of the planktonic community ("zoo" comes from the Greek word for ''animal''). Plankton are aquatic organisms that are unable to swim effectively against currents, and consequently drift or are carried along by ...

and small invertebrates. It is a

protandric hermaphrodite In reproductive biology, a hermaphrodite () is an organism that has both kinds of reproductive organs and can produce both gametes associated with male and female sexes. Many taxonomic groups of animals (mostly invertebrates) do not have separ ...

, starting adult life as a female and later becoming a male.

References

External links

* {{Taxonbar, from=Q670614 navarchus Fish of Palau Fish described in 1831 Taxa named by Frédéric Cuvier