The flathead congoli (''Halaphritis platcephala'') is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

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 ...

, belonging to 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 ...

Bovichtidae Bovichtidae, the temperate icefishes or thornfishes, is a family of marine ray-finned fishes, classified in the suborder Notothenioidei of the order Perciformes. They are native to coastal waters off Australia, New Zealand, and South America ...

, the thornfishes or temperate icefishes. It is native to the seas off southeastern Australia. This species is the only known member of its

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

Taxonomy

The flathead congoli was first formally described in 2002 by

Peter R. Last Peter Robert Last is an Australian ichthyologist, curator of the Australian National Fish Collection and a senior principal research scientist at CSIRO Marine and Atmospheric Research (CMAR) in Hobart, Tasmania. He is an elasmobranch expert and ...

Arkady Vladimirovich Balushkin Arkady () is a Slavic masculine given name, ultimately derived from the Greek language, Greek name Αρκάδιος, meaning “from Arcadia (region), Arcadia”. Endeared versions of the name are ''Arkasha''. The Latin equivalent is Arcadius (disa ...

and J. Barry Hutchins with the type locality given as

Port Davey Port Davey is an embayment, oceanic inlet located in the South West Tasmania, south west region of Tasmania, Australia. Port Davey was named by explorer James Kelly (Australian explorer), James Kelly in honour of Thomas Davey (governor), Thomas ...

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 ...

. It is the only species in the

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unisp ...

genus ''Halaphritis''. The name of the genus ''Halaphritis'' is a compound of ''halos'' meaning "sea" and ''aphritis'' which is a name which dates back to

Aristotle Aristotle (; 384–322 BC) was an Ancient Greek philosophy, Ancient Greek philosopher and polymath. His writings cover a broad range of subjects spanning the natural sciences, philosophy, linguistics, economics, politics, psychology, a ...

, who used it for a type of

anchovy An anchovy is a small, common forage fish of the Family (biology), family Engraulidae. Most species are found in marine waters, but several will enter brackish water, and some in South America are restricted to fresh water. More than 140 speci ...

whitebait Whitebait is a collective term for the immature fry of fish, typically between long. Such young fish often travel together in schools along coasts, and move into estuaries and sometimes up rivers where they can be easily caught using fine-mes ...

, but the authors used as an allusion to ''

Pseudaphritis The congoli (''Pseudaphritis urvillii''), also known as the freshwater flathead, marble fish, marbled flathead, sand trout, sanding, sandy, sandy whiting or tupong, is a species of marine ray-finned fish. It is the only species of fish in the ...

'', emphasising this species marine habitat compared to the superficially similar congoli (''Pseudaphritis urvillii''), a predominantly fresh and brackish water species. The specific name ''platycephala'' means "flat head" alluding to the flattened head of this species.

Description

The flathead congoli has a flattened, elongate and shallow body, its depth being around 15% of its

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

. The head is quite large having its length being around 31% of the standard length and is highly flattened and has a wide rounded snout. The large eyes are close to each other and are on the back of the head. The mouth is large and terminal and there are small bristle-like teeth arranged in bands in each jaw. There is a small, weak, flattened spine on the operculum near the upper edge. The head and body, as well as the caudal and pectoral fins are covered in small

ctenoid scales A fish scale is a small rigid plate that grows out of the skin of a fish. The skin of most jawed fishes is covered with these protective scales, which can also provide effective camouflage through the use of reflection and colouration, as w ...

. 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 epithelia ...

is straight and clearly visible. The first dorsal fin has 9 spines is small with a short base with its origin just in front of the origin of the

pectoral fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish aquatic locomotion, swim. Apart from the tail or caudal fin, fish fins have no direct connection with the vertebral column ...

s and the second dorsal fin has a base which is around three times the length of first. The

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 ...

contains 23 soft rays, has a long base and is similar in shape and sits opposite the second dorsal fin, although it is positioned slightly to its rear, The caudal fin is slightly rounded. The pectoral fins are large and rounded. The

pelvic fin Pelvic fins or ventral fins are paired fins located on the ventral (belly) surface of fish, and are the lower of the only two sets of paired fins (the other being the laterally positioned pectoral fins). The pelvic fins are homologous to the hi ...

s ait at the jugular and are approximately arrow-shaped with the central fin rays being the longest. The maximum recorded

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 ...

was . The overall colour is dusky shading to paler ventrally with around five wide vague darkish bands along the back and flanks while the fins have pale margins.

Distribution and habitat

The flathead congoli is endemic to southeastern Australia where it is found around Tasmania and off

Wilsons Promontory Wilsons Promontory is a peninsula that forms the southernmost part of the Australian mainland, located in the state of Victoria (Australia), Victoria. South Point (Wilsons Promontory), South Point at is the southernmost tip of Wilsons Promon ...

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 ...

. It is found on shallow, semi-exposed reefs where it sheltersbelow ledges and deep within caves during the day.

Biology

The flathead congoli appears to be adapted for crawling around the substrate in confined spaces. Captive specimens have been observed to crawl over the substrate in preference to swimming. They have been fed on shrimps and other small crustaceans in captivity.

References

{{Taxonbar, from=Q2673400 Bovichtidae Taxa named by Peter R. Last Taxa named by Arkady Vladimirovich Balushkin Taxa named by J. Barry Hutchins Fish described in 2002