The sixbar wrasse or six-banded wrasse (''Thalassoma hardwicke'') is a species of

wrasse The wrasses are a family, Labridae, of marine fish, many of which are brightly colored. The family is large and diverse, with over 600 species in 81 genera, which are divided into 9 subgroups or tribes. They are typically small, most of them le ...

in the family Labridae, native to 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 th ...

and 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 continen ...

. It is an inhabitant of

reef A reef is a ridge or shoal of rock, coral or similar relatively stable material, lying beneath the surface of a natural body of water. Many reefs result from natural, abiotic processes— deposition of sand, wave erosion planing down rock out ...

environments at depths from the surface down to . This species can grow to in

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 ...

, though most individuals do not exceed . It is of minor importance to local

commercial fisheries Commercial fishing is the activity of catching fish and other seafood for commercial profit, mostly from wild fisheries. It provides a large quantity of food to many countries around the world, but those who practice it as an industry must often ...

and can also be found in the

aquarium An aquarium (plural: ''aquariums'' or ''aquaria'') is a vivarium of any size having at least one transparent side in which aquatic plants or animals are kept and displayed. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, aq ...

trade.

Description

The sixbar wrasse grows to a maximum total length of . The dorsal fin has 8 spines and 12 to 14 soft rays, while the anal fin has 3 spines and 11 soft rays. It is a greenish fish with four dark bars on its upper body and two more saddle-like bars over the

caudal peduncle 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 se ...

. In larger adults, the head has a number of pink streaks radiating from near the eye.

Distribution and habitat

The sixbar wrasse is native to the tropical Indo-Pacific between 30°N and 32°S. Its range extends from East Africa and Madagascar to Japan, Indonesia, the Philippines, northern Australia and various island groups in the Western Pacific. It is found on coral reefs, reef slopes and in lagoons, down to depths of or more.

Ecology

The sixbar wrasse is diurnal and has a home range that exceeds . It forms small groups and feeds on

plankton Plankton are the diverse collection of organisms found in Hydrosphere, water (or atmosphere, air) that are unable to propel themselves against a Ocean current, current (or wind). The individual organisms constituting plankton are called plankt ...

ic and

benthic The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from ancient Greek, βένθος (bénthos), meaning "t ...

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...

foraminifer Foraminifera (; Latin for "hole bearers"; informally called "forams") are single-celled organisms, members of a phylum or class of amoeboid protists characterized by streaming granular ectoplasm for catching food and other uses; and commonly an ...

ans, small fish, fish eggs and fish larvae. Males and females form pairs during the breeding season, and at this time males develop a gaudier colour and a black spot in the centre of the caudal fin. An aquarium fish of this species was observed to use a rock as an anvil. The fish was fed pellets that were too hard for it to chew and too large for it to swallow. The fish carried each pellet to a particular rock where it succeeded in breaking the pellet in pieces. It used the same behaviour and the same rock on a number of occasions, demonstrating a capacity for remembering how to solve the hard-pellet problem.

Use in aquaria

The sixbar wrasse is sometimes seen in the aquarium trade. It appreciates a large tank with a sandy base and a number of rocks to provide caves and crevices for shelter and hunting. It may move aquarium objects around to discover tubeworms, molluscs and other invertebrates underneath. It will also feed on shrimps, crabs and small fish, bashing larger prey on rocks to break them in pieces. It is capable of jumping out of the aquarium and will submerge itself in the sand when frightened.

Status

The sixbar wrasse is a common species with a wide range. Although sometimes collected for the aquarium trade, this is thought to be of only local significance and no other major threats have been identified, so the

International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

has assessed its conservation status as being of "

least concern A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. T ...

Species description

''Thalassoma hardwicke'' was originally formally described as ''Sparus hardwicke'' in 1830 by the

English English usually refers to: * English language * English people English may also refer to: Peoples, culture, and language * ''English'', an adjective for something of, from, or related to England ** English national ide ...

John Whitchurch Bennett John Whitchurch Bennett (28 July 1790 – 10 June 1853) was a British army officer, official and printer, known as a naturalist. Life Bennett served in the Royal Marines from 1806 to 1815. He transferred to the British Army in 1815, and in 1816 was ...

(1790-1853) with the type locality given as the south coast of

Ceylon Sri Lanka (, ; si, ශ්‍රී ලංකා, Śrī Laṅkā, translit-std=ISO (); ta, இலங்கை, Ilaṅkai, translit-std=ISO ()), formerly known as Ceylon and officially the Democratic Socialist Republic of Sri Lanka, is an ...

. The specific name honours Bennett's friend and fellow naturalist, Major-General

Thomas Hardwicke Major-General Thomas Hardwicke (1756 – 3 March 1835) was an English soldier and naturalist who was in India from 1777 to 1823. He collected numerous specimens of natural history and had them painted by Indian artists. From these paintings ma ...

(1756-1835).

References

External links

* {{Taxonbar, from=Q2634701 Sixbar wrasse Fish described in 1830 Taxa named by John Whitchurch Bennett Fish of the Indian Ocean Fish of the Pacific Ocean