The blue-throated wrasse (''Notolabrus tetricus''), also known as the bluehead, bluehead parrotfish, bluenose, bluenose parrotfish, bluethroat parrotfish, blue-throat wrasse, kelpie, lilac banded parrotfish, rocky bream, rocky cod, rotfish or winter bream, is a species of marine

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class of bony fish that comprise over 50% of living vertebrate species. They are so called because of their lightly built fins made of webbings of sk ...

from the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Labridae, the

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

s. It is found in the Indian and Pacific Ocean off the south-eastern coasts of Australia.

Taxonomy

''Notolabrus tetricus'' was first formally described in 1840 as ''Labrus tetricus'' by

Scottish Scottish usually refers to something of, from, or related to Scotland, including: *Scottish Gaelic, a Celtic Goidelic language of the Indo-European language family native to Scotland *Scottish English *Scottish national identity, the Scottish ide ...

naturalist Natural history is a domain of inquiry involving organisms, including animals, fungi, and plants, in their natural environment, leaning more towards observational than experimental methods of study. A person who studies natural history is cal ...

John Richardson (1787-1865) with the type locality given as Port Arthur in Tasmania. The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

''tetricus'' means "grim", a reference to the somewhat forbidding appearance of large males. This species has been reported to hybridize with ''

Notolabrus fucicola ''Notolabrus fucicola'', the banded parrotfish, blue wrasse, kelpie, New Zealand banded wrasse, purple parrotfish, saddled wrasse, Southern purple wrasse, Southern wrasse, winter bream or yellow-saddled wrasse, is a species of wrasse native to th ...

''.

Description

The body of the blue throated wrasse is moderately deep, and its snout is somewhat rounded. The males vary in colour and can have bodies which have greyish, greenish-blue or reddish-orange background colour. The head is pale with a blue chin and throat, the

pectoral Pectoral may refer to: * The chest region and anything relating to it. * Pectoral cross, a cross worn on the chest * a decorative, usually jeweled version of a gorget * Pectoral (Ancient Egypt), a type of jewelry worn in ancient Egypt * Pectora ...

pelvic The pelvis (: pelves or pelvises) is the lower part of an anatomical trunk, between the abdomen and the thighs (sometimes also called pelvic region), together with its embedded skeleton (sometimes also called bony pelvis or pelvic skeleton). ...

and

anal fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported o ...

s are yellow. There is an obvious, thick white vertical bar around the middle part of the body. Females and juveniles are greenish or brownish with a mottled pattern, they frequently show a large vertical patch with smaller white patches on the body next to it. Older females develop paler colouration to the rear of the vertical bar. This species can attain a

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

of but the most common size for males is while females are normally .

Distribution

The blue-headed wrasse is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to the waters of south eastern Australia where it is found from

Newcastle, New South Wales Newcastle, also commonly referred to as Greater Newcastle ( ; ), is a large Metropolitan area, metropolitan area and the second-most-populous such area of New South Wales, Australia. It includes the cities of City of Newcastle, Newcastle and Ci ...

and

Sydney Sydney is the capital city of the States and territories of Australia, state of New South Wales and the List of cities in Australia by population, most populous city in Australia. Located on Australia's east coast, the metropolis surrounds Syd ...

New South Wales New South Wales (commonly abbreviated as NSW) is a States and territories of Australia, state on the Eastern states of Australia, east coast of :Australia. It borders Queensland to the north, Victoria (state), Victoria to the south, and South ...

south to

Victoria Victoria most commonly refers to: * Queen Victoria (1819–1901), Queen of the United Kingdom and Empress of India * Victoria (state), a state of Australia * Victoria, British Columbia, Canada, a provincial capital * Victoria, Seychelles, the capi ...

and

Tasmania Tasmania (; palawa kani: ''Lutruwita'') is an island States and territories of Australia, state of Australia. It is located to the south of the Mainland Australia, Australian mainland, and is separated from it by the Bass Strait. The sta ...

, east to

South Australia South Australia (commonly abbreviated as SA) is a States and territories of Australia, state in the southern central part of Australia. With a total land area of , it is the fourth-largest of Australia's states and territories by area, which in ...

. They are ones of the dominant species of reef fish off northern Tasmania and southern Australia.

Habitat

The blue-headed wrasse occurs in sheltered to exposed rocky reefs, frequently being recorded where there is sea weeds as deep as . The adults are normally to be found near the sea bed and prefer deeper waters than the juvenile fish. The smaller fish are found in shallower water than the adults where they frequent beds of

kelp Kelps are large brown algae or seaweeds that make up the order (biology), order Laminariales. There are about 30 different genus, genera. Despite its appearance and use of photosynthesis in chloroplasts, kelp is technically not a plant but a str ...

and other seaweeds, as well as sea grass.

Biology

It is a

carnivorous A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose nutrition and energy requirements are met by consumption of animal tissues (mainly mu ...

fish which mainly feeds on

mollusc Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum ...

s and

crustacean Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquatic arthrop ...

s. The blue-throated wrasse is a

protogynous hermaphrodite Sequential hermaphroditism (called dichogamy in botany) is one of the two types of hermaphroditism, the other type being simultaneous hermaphroditism. It occurs when the organism's sex changes at some point in its life. A sequential hermaphrodite ...

, females change sex into males, which happens after they attain 4 years of age, and this occurs in 12% of females each year. This

oviparous Oviparous animals are animals that reproduce by depositing fertilized zygotes outside the body (i.e., by laying or spawning) in metabolically independent incubation organs known as eggs, which nurture the embryo into moving offsprings kno ...

species spawns in the spring and form pairs to do so. It lives in

harems A harem is a domestic space that is reserved for the women of the house in a Muslim family. A harem may house a man's wife or wives, their pre-pubescent male children, unmarried daughters, female domestic Domestic worker, servants, and other un ...

of a single large male and a number of females. This is a long-lived species which lives in excess of 15 years.

Human usage

Blue-throated wrasse are a quarry species for recreational and commercial fisheries. Live fish have been marketed since the early 1990s and the total catch of this species and of ''N. fucicola'' increased from less than 10 tonnes to nearly , 60 tonnes in 1995/96. The main market is restaurants in Sydney. It is frequently caught using hook and line but it is also taken by trawlers and by commercial gillnets. Spearfishers also take this species, and it is common bycatch in lobster fisheries. Some states in Australia have set bag limits.

Conservation

The blue-throated wrasse is subject to a minimum size limit in Vicorie (28 cm) and in Tasmania (30 cm) and fishing licenses are restricted in each of thee states. The biology of this species makes it vulnerable to fishing pressure as the large, territorial males are most easily taken and this leads to a reduction in breeding success and lower recruitment into the population, There are concerns that the larger minimum size for catch in Tasmania does not provide adequate protection. Habitat deterioration caused by pollution and sedimentation may also affect this species.

Gallery

File:Notolabrus tetricus Wrasse, Taroona , TAS, Australia imported from iNaturalist photo 114155524 (cropped).jpg, Terminal phase File:Notolabrus tetricus 185973013.jpg, Terminal phase File:Notolabrus tetricus 189995491.jpg, Terminal phase File:Notolabrus tetricus 189995642.jpg, Initial phase File:Meuschenia galii and Notolabrus tetricus P1091645.JPG, Initial phase, with a blue-lined leatherjacket ('' Meuschenia galii'') File:Notolabrus tetricus Wrasse, Victoria, Australia imported from iNaturalist photo 77551295.jpg, Juvenile File:Notolabrus tetricus Wrasse, Nepean Pl, Point Nepean Rd, Portsea VIC 3944, Australia imported from iNaturalist photo 170671055.jpg, Juvenile File:Notolabrus tetricus Wrasse, Victoria, Australia imported from iNaturalist photo 106625013.jpg, Juvenile

References

{{Taxonbar, from=Q2085934 blue-throated wrasse Fish of Victoria (state) Marine fish of Tasmania blue-throated wrasse