Randall's snapper (''Randallichthys filamentosus'') is a species of

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 ...

, a snapper 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 ...

Lutjanidae Lutjanidae or snappers are a family of perciform fishes, mainly marine but with some members inhabiting estuaries and, in some cases, fresh water (e.g., '' Lutjanus goldiei''). The family includes about 113 species. Most species are used for foo ...

. It is native to the

Indo-Pacific The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...

region.

Taxonomy

Randall’s snapper was first formally described in 1970 as ''Etelis filamenosus'' by the French

ichthyologist Ichthyology is the branch of zoology devoted to the study of fish, including bony fish (Osteichthyes), cartilaginous fish (Chondrichthyes), and jawless fish (Agnatha). According to FishBase, 35,800 species of fish had been described as of March 2 ...

Pierre Fourmanoir with the type locality given as

New Caledonia New Caledonia ( ; ) is a group of islands in the southwest Pacific Ocean, southwest of Vanuatu and east of Australia. Located from Metropolitan France, it forms a Overseas France#Sui generis collectivity, ''sui generis'' collectivity of t ...

. In 1977 William D. Anderson Jr, Harry T. Kami and G. David Johnson placed ''E. filamentosus'' into 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 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 ...

''Randallichthys''. 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 ...

means “filamentous” which Fourmanoir gave it because the

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

had several

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 ...

rays which extended into filaments, although this is not a feature seen in other specimens.

Etymology

The name of the genus honours the American ichthyologist

John Ernest Randall John Ernest "Jack" Randall (May 22, 1924 – April 26, 2020) was an American ichthyologist and a leading authority on coral reef fishes. Randall described over 800 species and authored 11 books and over 900 scientific papers and popular articles. ...

who worked at the

Bishop Museum The Bernice Pauahi Bishop Museum, designated the Hawaii State Museum of Natural and Cultural History, is a museum of history and science in the historic Kalihi district of Honolulu, Hawaii, Honolulu on the Hawaiian island of Oʻahu. Founded in 1 ...

Honolulu Honolulu ( ; ) is the List of capitals in the United States, capital and most populous city of the U.S. state of Hawaii, located in the Pacific Ocean. It is the county seat of the Consolidated city-county, consolidated City and County of Honol ...

, and who made a significant contribution to the study of Indo-Pacific fishes.

Description

Randall's snapper has a relatively elongate body with a short snout, blunt head and a flattened space between the eyes. The lower jaw is protruding. The vomerine teeth are arranged in a chevron and there are no teeth on the tongue. The

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 ...

has 10 spines and 12 soft rays while 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 ...

has 3 spines and 9 soft rays, both these spine have no scales on their bases. The short

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 do not extend as far as the anus and contains 16-17 rays. The caudal fin is lunate and in young individuals the rays of the lower lobe may be produced into filaments. The overall colour of this fish is rosy with a yellowish hue on the back. The dorsal fin is greyish yellow and the anal and caudal fins are rosy. All of these fins, as well as 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 have dark to black margins. This species attains a maximum

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 , although is more typical.

Distribution and habitat

Randall's snapper is found in the eastern Indian Ocean and the western Pacific Ocean. This species has been recorded from New Caledonia, the type locality, the

Hawaiian Islands The Hawaiian Islands () are an archipelago of eight major volcanic islands, several atolls, and numerous smaller islets in the Pacific Ocean, North Pacific Ocean, extending some from the Hawaii (island), island of Hawaii in the south to nort ...

, the Cook Islands, the

Ryukyu Islands The , also known as the or the , are a chain of Japanese islands that stretch southwest from Kyushu to Geography of Taiwan, Taiwan: the Ryukyu Islands are divided into the Satsunan Islands (Ōsumi Islands, Ōsumi, Tokara Islands, Tokara and A ...

Izu Islands The are a group of volcanic islands stretching south and east from the Izu Peninsula of Honshū, Japan. Administratively, they form two towns and six villages; all part of Tokyo Prefecture. The largest is Izu Ōshima, usually called simply Ōsh ...

Ogasawara Islands The Bonin Islands, also known as the , is a Japanese archipelago of over 30 subtropical and tropical islands located around SSE of Tokyo and northwest of Guam. The group as a whole has a total area of but only two of the islands are permanen ...

, Chuuk,

Majuro Majuro (; Marshallese language, Marshallese: ' ) is the Capital city, capital and largest city of the Marshall Islands. It is also a large coral atoll of 64 islands in the Pacific Ocean. It forms a legislative district of the Ratak Chain, Ratak ( ...

, the

Society Islands The Society Islands ( , officially ; ) are an archipelago in the South Pacific Ocean that includes the major islands of Tahiti, Mo'orea, Moorea, Raiatea, Bora Bora and Huahine. Politically, they are part of French Polynesia, an overseas country ...

and Tonga. It has also been found at scattered localities around Australia, off Esperance on the southern coast of

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 ...

, Scott Reef off northwestern Western Australia and

Lord Howe Island Lord Howe Island (; formerly Lord Howe's Island) is an irregularly crescent-shaped volcanic remnant in the Tasman Sea between Australia and New Zealand, part of the Australian state of New South Wales. It lies directly east of mainland Port ...

in the

Tasman Sea The Tasman Sea is a marginal sea of the South Pacific Ocean, situated between Australia and New Zealand. It measures about across and about from north to south. The sea was named after the Dutch explorer Abel Janszoon Tasman, who in 1642 wa ...

. This is an uncommon species and will probably be proven to be more widespread. It occurs in comparatively deep water at depths between over rocky substrates.

Fisheries

Randall's snapper is a species which is of commercial importance in places in which it occurs, albeit of lesser importance, and they are typically caught using hook and line. The flesh is considered to be of good quality and is sold fresh.

References

{{Taxonbar, from=Q2158650 Randall's snapper Fish of Hawaii Fish of New Caledonia Fauna of the Cook Islands Taxa named by Harry T. Kami Taxa named by Pierre Fourmanoir Randall's snapper