'' Monotaxis heterodon'', the redfin emperor, 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 ...

belonging to 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 ...

Lethrinidae The Lethrinidae are a family of fishes in the order Perciformes commonly known as emperors, emperor breams, and pigface breams. These fish are found in tropical waters of the Pacific and Indian Oceans, and ''Lethrinus atlanticus'' is also found ...

, the emperors and emperor breams. This fish is found in the Indian and Western Pacific Oceans.

Taxonomy

''Monotaxis heterodon'' was first formally described as ''Pagrus heterodon'' in 1854 by the Dutch

physician A physician (American English), medical practitioner (Commonwealth English), medical doctor, or simply doctor, is a health professional who practices medicine, which is concerned with promoting, maintaining or restoring health through th ...

, herpetologist and

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, 33,400 species of fish had been described as of Octobe ...

Pieter Bleeker Pieter Bleeker (10 July 1819 – 24 January 1878) was a Dutch medical doctor, ichthyologist, and herpetologist. He was famous for the ''Atlas Ichthyologique des Indes Orientales Néêrlandaises'', his monumental work on the fishes of East Asia ...

with its type locality given as

Halmahera Halmahera, formerly known as Jilolo, Gilolo, or Jailolo, is the largest island in the Maluku Islands. It is part of the North Maluku province of Indonesia, and Sofifi, the capital of the province, is located on the west coast of the island. Hal ...

in Indonesia. This taxon was regarded as a synonym of '' Monotaxis grandoculis'' but is now considered to be a valid species. Some authors place the genus Monotaxis 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 ...

Monotaxinae but the 5th edition of ''

Fishes of the World ''Fishes of the World'' by the American ichthyologist Joseph S. Nelson (1937–2011) is a standard reference for fish systematics. Now in its fifth edition (2016), the work is a comprehensive overview of the diversity and classification of the ...

'' does not recognise the subfamilies traditionally accepted within the family Lethrinidae as valid. The family Lethrinidae is classified by the 5th edition of ''Fishes of the World'' as belonging to the

order Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of d ...

Spariformes.

Etymology

''Monotaxis heterodon'' has 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 ...

''heterodon'' which means "different teeth" which was an allusion to the single row of molar teeth compared to the 2 or 3 rows of '' Pagrus'', the genus Bleeker placed it in.

Description

''Monotaxis heterodon'' differs from ''M. grandoculis'', with which it used to be considered synonymous, by having 18 rather than 19 transverse scale rows on the cheek. This species also has thin, vertical white bars along the upper body and the juveniles differ in having no vertical bar through the eye and no black blotches. It is an overall sovery greyish colour on the body, broken by the thin white vertical bars along the back, these are only one or two scale rows wide (3-4 on ''M. grandocularis''). There is a black blotch on the

axil A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, st ...

, of the

pectoral 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 ...

, the lips are brownish to reddish and the fins are tinged with yellowish to reddish.

Distribution and habitat

''Monotaxis heterodon'' occurs in the Indian and Pacific Oceans. In the Indian Ocean it occurs at the Seychelles, Maldives and Sri lanka, as well as Christmas Island and the Cocos (Keeling) Islands. It is found throughout the islands of Indonesia east into the Pacific Ocean where it occurs east to Fiji, south to the

Great Barrier Reef The Great Barrier Reef is the world's largest coral reef system composed of over 2,900 individual reefs and 900 islands stretching for over over an area of approximately . The reef is located in the Coral Sea, off the coast of Queensland, ...

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 P ...

and

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. This species is found on sheltered coral reefs down to .

References

{{Taxonbar, from=Q46341640

heterodon ''Heterodon'' is a genus of harmless colubrid snakes endemic to North America.Platt, Dwight R. 1983. Heterodon'. Catalogue of American Amphibians and Reptiles. Society for the Study of Amphibians and Reptiles, 351: 1-2. They are stout with up ...

Fish described in 1854 Taxa named by Pieter Bleeker