''Pseudanthias parvirostris'', the sunset anthias is a species of 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 hor ...

in the

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end subfamily botanical names with "-oideae", and zoologi ...

Anthiinae Anthias are members of the family Serranidae and make up the subfamily Anthiinae. Anthias make up a sizeable portion of the population of pink, orange, and yellow reef fishes seen swarming in most coral reef photography and film. The name Anthi ...

of the

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

Serranidae The Serranidae are a large family of fishes belonging to the order Perciformes. The family contains about 450 species in 65 genera, including the sea basses and the groupers (subfamily Epinephelinae). Although many species are small, in some case ...

, the

grouper Groupers are fish of any of a number of genera in the subfamily Epinephelinae of the family Serranidae, in the order Perciformes. Not all serranids are called "groupers"; the family also includes the sea basses. The common name "grouper" is u ...

s and sea basses. It is found in the Indo-West Pacific Ocean. It occasionally makes its way into the aquarium trade. It grows to a size of 7.5 cm in length.

Description

''Pseudanthias parvirostris'' has a somewhat elongated, moderately compressed body which is around 3 times as long (in

standard 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 m ...

as it is deep. The males have a thickened upper lip which is a little pointed and can be moved up and down, although this is less marked in this species than in related ''

Pseudanthias ''Pseudanthias'' is a genus of colourful reef fishes of the subfamily Anthiinae, part of the family Serranidae, the groupers and sea basses. They are found in the Indo-Pacific. The species belonging to this genus have a diet consisting of zoopla ...

''. It has a moderately large, obliquely angled mouth in which the

maxilla The maxilla (plural: ''maxillae'' ) in vertebrates is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The t ...

extends to the level of or beyond the rear edge of the eye. The

lateral line The lateral line, also called the lateral line organ (LLO), is a system of sensory organs found in fish, used to detect movement, vibration, and pressure gradients in the surrounding water. The sensory ability is achieved via modified epithelial ...

is curved and follows the curve of the dorsal profile. The

dorsal fin A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through conv ...

has 10 spines and 15-16 soft rays and 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 se ...

has 3 spines and 7 soft rays. The upper third of the body is yellowish in colour in males while the rest of the body is pinkish and there is a magenta stripe which runs between their eyes and from the upper margin of the eyes to the origin of the dorsal fin. The dorsal fin and lobes of the caudal fin are magenta. The females are overall yellow, sometimes a darker yellowish-orange, with a similar magenta stripe between the eyes as the male. It grows to a maximum standard length of .

Distribution

''Pseudanthias parvirostris'' is found in the Indian Ocean 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 ...

. Its range extends from Japan south as far as Australia, west to the Madives and east to the

Solomon Islands Solomon Islands is an island country consisting of six major islands and over 900 smaller islands in Oceania, to the east of Papua New Guinea and north-west of Vanuatu. It has a land area of , and a population of approx. 700,000. Its capita ...

. In Australia it is found in the

Coral Sea The Coral Sea () is a marginal sea of the South Pacific off the northeast coast of Australia, and classified as an interim Australian bioregion. The Coral Sea extends down the Australian northeast coast. Most of it is protected by the Fre ...

and at

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 cover ...

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 th ...

Habitat and biology

''Pseudanthias parvirostris'' is found on outer reef slopes at depths between , most commonly at depths of more than . They are usually found in small aggregations close to the bottom, where there are patch reefs on slopes dominated by sand or rubble. The social grouping is that there is a dominant male which guards a

harem Harem (Persian: حرمسرا ''haramsarā'', ar, حَرِيمٌ ''ḥarīm'', "a sacred inviolable place; harem; female members of the family") refers to domestic spaces that are reserved for the women of the house in a Muslim family. A hare ...

made up of a small group of females. They are nonadric

protogynous hermaphrodites 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, ...

and when the dominant male is lost themost dominant female changes sex and colour to that of the male. which takes around two weeks, and takes over the harem/ Where they are

sympatric In biology, two related species or populations are considered sympatric when they exist in the same geographic area and thus frequently encounter one another. An initially interbreeding population that splits into two or more distinct species sh ...

''P. parvirostris'' may mix with groups of '' Pseudanthias smithvanizi''.

Taxonomy

''Pseudanthias parvirostris'' was first formally described as ''Anthias parvirostris'' by John E. Randall and Roger Lubbock in 1981 with the type locality given as the outer reef slope on the western side of Alite Reef, off

Malaita Malaita is the primary island of Malaita Province in Solomon Islands. Malaita is the most populous island of the Solomon Islands, with a population of 161,832 as of 2021, or more than a third of the entire national population. It is also the se ...

in the Solomon Islands. 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 ...

''parvirostris'' refers to the relatively small snout developed by the males of this species. Some authorities classify this species within the

subgenus In biology, a subgenus (plural: subgenera) is a taxonomic rank directly below genus. In the International Code of Zoological Nomenclature, a subgeneric name can be used independently or included in a species name, in parentheses, placed between t ...

''Mirolabrichthys'', and also that it is intermediate between that subgenus and the subgenus ''Pseudanthias''.

Utilisation

''Pseudanthias parvirostris'' is rare 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, although they are among the easier ''Pseudanthias'' species to keep, although as they are relatively deep water fish they require dimly lit aquaria.

References

{{Taxonbar, from=Q579337 parvirostris Taxa named by John Ernest Randall Taxa named by Roger Lubbock Fish described in 1981