''Rogadius'' is a

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 ...

of 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 ...

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 ...

Platycephalidae The Platycephalidae are a Family (biology), family of marine ray-finned fish, most commonly referred to as flatheads. They are relatives of the lionfish, and belong to the order Perciformes. Taxonomy Platycephalidae was first proposed as a famil ...

. These fishes are native to the

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or approximately 20% of the water area of Earth#Surface, Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia (continent), ...

and the western

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 ...

Taxonomy

''Rogadius'' was first formally proposed as a genus in 1908 by the American

ichthyologists 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 ...

David Starr Jordan David Starr Jordan (January 19, 1851 – September 19, 1931) was the founding president of Stanford University, serving from 1891 to 1913. He was an ichthyologist during his research career. Prior to serving as president of Stanford Universi ...

and

Robert Earl Richardson Robert Earl Richardson (28 November 1877 – 14 April 1935) was an American aquatic biologist and ichthyologist. Richardson was born in Brighton, Illinois, on 28 November 1877. His father was Robert and his mother was Emily Dickerson Richardson. H ...

with ''Platycephalus asper'', which had been described in 1829 by

Georges Cuvier Jean Léopold Nicolas Frédéric, baron Cuvier (23 August 1769 – 13 May 1832), known as Georges Cuvier (; ), was a French natural history, naturalist and zoology, zoologist, sometimes referred to as the "founding father of paleontology". Cuv ...

from

Nagasaki , officially , is the capital and the largest Cities of Japan, city of Nagasaki Prefecture on the island of Kyushu in Japan. Founded by the Portuguese, the port of Portuguese_Nagasaki, Nagasaki became the sole Nanban trade, port used for tr ...

, designated as its

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

. This genus is

classified Classified may refer to: General *Classified information, material that a government body deems to be sensitive *Classified advertising or "classifieds" Music *Classified (rapper) (born 1977), Canadian rapper * The Classified, a 1980s American ro ...

within the family Playtcephalidae, the flatheads which the 5th edition of ''

Fishes of the World ''Fishes of the World'' is a standard reference for the systematics of fishes. It was first written in 1976 by the American ichthyologist Joseph S. Nelson (1937–2011). Now in its fifth edition (2016), the work is a comprehensive overview of t ...

'' classifies within the

suborder Order () is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between family and class. In biological classification, the order is a taxonomic rank used in the classification of organisms and recognized ...

Platycephaloidei Platycephaloidei is a suborder of ray-finned fishes, part of the Order (biology), order Scorpaeniformes, and includes the Platycephalidae, flatheads, ghost flatheads and Triglidae, sea robins. Taxonomy Platycephaloidei was first recognised and n ...

in the

order Order, ORDER or Orders may refer to: * A socio-political or established or existing order, e.g. World order, Ancien Regime, Pax Britannica * Categorization, the process in which ideas and objects are recognized, differentiated, and understood ...

Scorpaeniformes The Scorpaeniformes are a diverse Order (biology), order of Actinopterygii, ray-finned fish, including the lionfishes and sculpins, but have also been called the Scleroparei. It is one of the five largest orders of bony fishes by number of spec ...

Etymology

''Rogadius'' is a latinisation of ''rogad'', an

Arabic Arabic (, , or , ) is a Central Semitic languages, Central Semitic language of the Afroasiatic languages, Afroasiatic language family spoken primarily in the Arab world. The International Organization for Standardization (ISO) assigns lang ...

name for the

bartail flathead The bartail flathead (''Platycephalus indicus''), also known as the Indian flathead, gobi or Indo-Pacific flathead, is a species of largely marine ray-finned fish belonging to the family Platycephalidae, the flatheads. This species is found in t ...

(''Platycephalus indicus'').

Species

''Rogadius'' contains seven species: * '' Rogadius asper'' (

Cuvier Jean Léopold Nicolas Frédéric, baron Cuvier (23 August 1769 – 13 May 1832), known as Georges Cuvier (; ), was a French natural history, naturalist and zoology, zoologist, sometimes referred to as the "founding father of paleontology". Cuv ...

, 1829) (Olive-tailed flathead) * '' Rogadius fehlmanni'' L. W. Knapp, 2012 * '' Rogadius mcgroutheri'' Imamura, 2007 (McGrouther's flathead) * '' Rogadius patriciae'' L. W. Knapp, 1987 (Black-banded flathead) * '' Rogadius pristiger'' (Cuvier, 1829) (Thorny flathead) * '' Rogadius serratus'' (Cuvier, 1829) (Serrated flathead) * '' Rogadius welanderi'' ( L. P. Schultz, 1966) (Welander's flathead)

Characteristics

''Rogadius'' flatheads have two or more preopercular spines have at least two spines on the

preoperculum This glossary of ichthyology is a list of definitions of terms and concepts used in ichthyology, the study of fishes. A B C ...

, with the upper spine being the longest. There is no elongation of the upper lobe 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 ...

with no elongated filament extending out from that fin. The first dorsal fin has between eight or nine spines. the second being equal in height to the third, while the second dorsal fin has no more than twelve soft rays. There are two separate patches of

vomerine teeth The vomer (; ) is one of the unpaired facial bones of the skull. It is located in the midsagittal line, and articulates with the sphenoid, the ethmoid, the left and right palatine bones, and the left and right maxillary bones. The vomer forms t ...

. There are between 48 and 56 pored scales, each with two pores, on 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 ...

with spines on the scales in the anterior portion of that line. The diagonal rows of scales run downwards and backwards over lateral line and the number of these rows is roughly about equal to the number of scales in the lateral line, typically with a difference of only one or two scales. The head has bony ridges which have many fine serrations on them and a single bony ridge on the side of the head underneath the eye with the lower margin of the suborbital not being clearly visible due to being turned inward. The lappet on the iris has two lobes. The maximum length attained by these fishes varies from a

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 ...

of in ''R. fehlmanni'' to 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 in ''R. pristiger''.

Distribution

''Rogadius'' flatheads are found in the Indian and Western Pacific Oceans from the

Red Sea The Red Sea is a sea inlet of the Indian Ocean, lying between Africa and Asia. Its connection to the ocean is in the south, through the Bab-el-Mandeb Strait and the Gulf of Aden. To its north lie the Sinai Peninsula, the Gulf of Aqaba, and th ...

to Tonga, north to southern Japan and south to Australia.

References

{{Taxonbar, from=Q2173712 Platycephalidae Taxa named by David Starr Jordan Taxa named by Robert Earl Richardson