''Callionymus belcheri'', Belcher's dragonet or the flathead dragonet, 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), ...

dragonet Dragonets are small Percomorpha, percomorph marine fish of the diverse family Callionymidae (from the Greek language, Greek ''kallis'', "beautiful" and ', "name") found mainly in the tropical waters of the western Indo-Pacific. They are Benthos, ...

native to the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is ...

waters off of

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

and

Papua New Guinea Papua New Guinea, officially the Independent State of Papua New Guinea, is an island country in Oceania that comprises the eastern half of the island of New Guinea and offshore islands in Melanesia, a region of the southwestern Pacific Ocean n ...

where it occurs at depths of from .

Description

''Callionymus belcheri'' has a yellowish to brown head and body with many small white spots on its back. The flanks are marked with white blotches which have dark brown margins. The underside is white. There are two

dorsal fin A dorsal fin is a fin on the back of most marine and freshwater vertebrates. Dorsal fins have evolved independently several times through convergent evolution adapting to marine environments, so the fins are not all homologous. They are found ...

s, the first dorsal fin is brownish in colour, with a distal margin that is often blackish and which in males has white spots. The second dorsal fin is marked wither with light and dark streaks or with small white spots. 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 ...

of males has a dark streak and in females is colourless or has dark spots on ots distal portion. The lower two-thirds of the

caudal 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 only ...

has brown spots. The preopercular spine has a concave ventral margin. There are a total of 4 spines in the dorsal fins and 9 soft rays with 8 soft rays in the anal fin. This species grows to a length of SL.

Distribution

''Callionymus belcheri'' occurs in

Queensland Queensland ( , commonly abbreviated as Qld) is a States and territories of Australia, state in northeastern Australia, and is the second-largest and third-most populous state in Australia. It is bordered by the Northern Territory, South Austr ...

from

Moreton Bay Moreton Bay is a bay located on the eastern coast of Australia from central Brisbane, Queensland. It is one of Queensland's most important coastal resources. The waters of Moreton Bay are a popular destination for recreational anglers and are ...

north to northern

New Guinea New Guinea (; Hiri Motu: ''Niu Gini''; , fossilized , also known as Papua or historically ) is the List of islands by area, world's second-largest island, with an area of . Located in Melanesia in the southwestern Pacific Ocean, the island is ...

and into the

Gulf of Carpentaria The Gulf of Carpentaria is a sea off the northern coast of Australia. It is enclosed on three sides by northern Australia and bounded on the north by the eastern Arafura Sea, which separates Australia and New Guinea. The northern boundary ...

, and westwards to northern

Western Australia Western Australia (WA) is the westernmost state of Australia. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. Western Aust ...

Habitat and biology

''Callionymus belcheri'' is a marine,

demersal 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 o ...

fish which occurs at depth ranges of . It has a varied diet which is mainly made up of invertebrates including

polychaete Polychaeta () is a paraphyletic class of generally marine Annelid, annelid worms, common name, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called c ...

worms,

gastropod Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and fro ...

bivalve Bivalvia () or bivalves, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class (biology), class of aquatic animal, aquatic molluscs (marine and freshwater) that have laterally compressed soft bodies enclosed b ...

s, small crustaceans and

scaphopods Scaphopoda (plural scaphopods , from Ancient Greek σκᾰ́φης ''skáphē'' "boat" and πούς ''poús'' "foot"), whose members are also known as tusk shells or tooth shells, are a class of shelled marine invertebrates belonging to the ph ...

. Larger fish also ate

echinoderm An echinoderm () is any animal of the phylum Echinodermata (), which includes starfish, brittle stars, sea urchins, sand dollars and sea cucumbers, as well as the sessile sea lilies or "stone lilies". While bilaterally symmetrical as ...

s and Caperllids. They appear to feed mainly in the late afternoon between 16:00 and 18:00, spending the rest of the day buried in sand or mud. This species spawns once a year in the southern Autumn, from March to May. They mature at lengths of in both sexes and females become less fertile towards the end of their lives.

Taxonomy and naming

The subspecies ''Callionymus belcheri recurvispinnis'', as named by Fricke. is regarded as a valid species by some authorities and is treated as such in

FishBase FishBase is a global species database of fish species (specifically finfish). It is the largest and most extensively accessed online database on adult finfish on the web.

, the authority used here for species of fish. 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 ...

honours the British Naval officer and explorer Admiral Sir

Edward Belcher Sir Edward Belcher (27 February 1799 – 18 March 1877) was a British naval officer, hydrographer, and explorer. Born in Nova Scotia, he was the great-grandson of Jonathan Belcher, who served as a colonial governor of Massachusetts, New ...

(1799-1877) who collected many specimens during his career and was a collector of shells.

References

{{Taxonbar, from=Q521788 B Fish described in 1844