''Rogadius'' is a genus of

marine Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military * ...

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 of ...

ray-finned fish belonging to the family

Platycephalidae The Platycephalidae are a family of marine fish, most commonly referred to as flatheads. They are relatives of the popular lionfish, belonging to the order Scorpaeniformes. Taxonomy Platycephalidae was first proposed as a family in 1839 by the E ...

. These fishes are native to the Indian Ocean and the western Pacific Ocean.

Taxonomy

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

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 Univer ...

and Robert Earl Richardson 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". Cuvier ...

from Nagasaki, designated as its type species. 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 roc ...

within the family Playtcephalidae, the flatheads which 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 ...

'' classifies within the

suborder Order ( la, ordo) 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 ...

Platycephaloidei in 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 ...

Scorpaeniformes.

Etymology

''Rogadius'' is a latinisation of ''rogad'', an Arabic name for the bartail flathead (''Platycephalus indicus'').

Species

''Rogadius'' contains seven species: * ''

Rogadius asper ''Rogadius'' is a genus of marine fish, marine, Demersal fish, demersal ray-finned fish belonging to the family (biology), family Platycephalidae. These fishes are native to the Indian Ocean and the western Pacific Ocean. Taxonomy ''Rogadius'' w ...

'' (

Cuvier Jean Léopold Nicolas Frédéric, Baron Cuvier (; 23 August 1769 – 13 May 1832), known as Georges Cuvier, was a French naturalist and zoologist, sometimes referred to as the "founding father of paleontology". Cuvier was a major figure in nat ...

, 1829) (Olive-tailed flathead) * ''

Rogadius fehlmanni ''Rogadius'' is a genus of marine, demersal ray-finned fish belonging to the family Platycephalidae. These fishes are native to the Indian Ocean and the western Pacific Ocean. Taxonomy ''Rogadius'' was first formally proposed as a genus in ...

'' L. W. Knapp, 2012 * ''

Rogadius mcgroutheri ''Rogadius'' is a genus of marine, demersal ray-finned fish belonging to the family Platycephalidae. These fishes are native to the Indian Ocean and the western Pacific Ocean. Taxonomy ''Rogadius'' was first formally proposed as a genus in ...

'' Imamura, 2007 (McGrouther's flathead) * ''

Rogadius patriciae ''Rogadius'' is a genus of marine, demersal ray-finned fish belonging to the family Platycephalidae. These fishes are native to the Indian Ocean and the western Pacific Ocean. Taxonomy ''Rogadius'' was first formally proposed as a genus in ...

'' L. W. Knapp, 1987 (Black-banded flathead) * ''

Rogadius pristiger ''Rogadius'' is a genus of marine fish, marine, Demersal fish, demersal ray-finned fish belonging to the family (biology), family Platycephalidae. These fishes are native to the Indian Ocean and the western Pacific Ocean. Taxonomy ''Rogadius'' w ...

'' (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 2 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 with no elongated filament extending out from that fin. The first dorsal fin has between 8 or 9 spines. the second being equal in height to the third, while the second dorsal fin has no more than 12 soft rays. There are 2 separate patches of vomerine teeth. There are between 48 and 56 pored scales, each with 2 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 epithelial ...

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 1 or 2 scales. The head has bony ridges which have many fine serrations on them, There uis 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 their anatomies. These data are used in many areas of ichthyology, including taxonomy and fisheries biology. Overall length * Standard length (SL) is the length of a fish m ...

of in ''R. fehlmanni'' to a maximum total length of in ''R. pristiger''.

Distribution

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