''Heminodus'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

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 ...

Peristediidae Peristediidae, the armored sea robins or armoured gurnards, is a family of ray-finned fishes belonging to the suborder Platycephaloidei in the order Scorpaeniformes. They are found in the deep water in the tropical and warm temperate of the wor ...

, the armoured gurnards or armored sea robins. It is currently considered to be a

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 "unispec ...

genus, its only species being ''Heminodus philippinus''.

Taxonomy

''Heminodus'' was first described as a genus in 1917 by the American

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 ...

Hugh McCormick Smith Hugh McCormick Smith, also H. M. Smith (November 21, 1865 – September 28, 1941) was an American ichthyologist and administrator in the United States Bureau of Fisheries. Biography Smith was born in Washington, D.C. In 1888, he received a Docto ...

when he was describing its only species ''H. phillipinus'' with its type locality being given as the

Mindanao Sea The Bohol Sea, also called the Mindanao Sea, is a sea located between the Visayas and Mindanao islands in the Philippines. It lies south of Bohol and Leyte and north of Mindanao. Siquijor and Camiguin are its two major islands. The major citi ...

off Tawi-tawi in the Philippines. Specimens collected in the eastern Indian Ocean off Western Australia between 1989 and 1991 were identified as probably belonging to the genus Hemidonus but were not identified to species, so may have been ''H. phillipinus'' or a new undescribed species. The genus name was not explained by Smith but means "half knot", may be an allusion to the short and spiny rostral processes as compared to the long and flat processes on the jaggedhead gurnard (''Gargariscus prionocephalus''). 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 ...

refers to the type locality.

Description

''Heminodus philippinus'' has a fusiform body armoured with bony plates and a large, flattened head with a broad snout which has a short, triangular rostral projection on either side, almost parallel to each other. The space between the eyes is concave with no clear ridges/ There are spines on the supraocular, parietal, posttemporal, opercular, and preopercular bones in the head. The large mouth is positioned below the snout and there are villiform teeth in the upper jaw and there are no other teeth in the mouth. There are 1 or 2 short barbels on the lip and none on chin. The armoured pates on the body are arranged in 4 rows and each plate has one, rear pointing spine. The head and upper body are pale red with yellowish green spots, the lower body is whitish. The fins are largely whitish with 2 dusky bands on the pectoral fin. There are between 6 and 8 spines in the first dorsal fin and between 18 and 21 soft rays in the second dorsal fin while the

anal 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 se ...

has 18-19 soft rays. This species reaches a maximum published length of .

Distribution and habitat

''Heminodus philippinus'' has been sited by

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...

the Philippines The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no), * bik, Republika kan Filipinas * ceb, Republika sa Pilipinas * cbk, República de Filipinas * hil, Republ ...

, the

South China Sea The South China Sea is a marginal sea of the Western Pacific Ocean. It is bounded in the north by the shores of South China (hence the name), in the west by the Indochinese Peninsula, in the east by the islands of Taiwan and northwestern Phil ...

, and the Andaman Coast of

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...

. This is a deep water

demersal fish Demersal fish, also known as groundfish, live and feed on or near the bottom of seas or lakes (the demersal zone).Walrond Carl . "Coastal fish - Fish of the open sea floor"Te Ara - the Encyclopedia of New Zealand. Updated 2 March 2009 They occ ...

living at depths between on the

continental shelf A continental shelf is a portion of a continent that is submerged under an area of relatively shallow water, known as a shelf sea. Much of these shelves were exposed by drops in sea level during glacial periods. The shelf surrounding an island ...

and

slope In mathematics, the slope or gradient of a line is a number that describes both the ''direction'' and the ''steepness'' of the line. Slope is often denoted by the letter ''m''; there is no clear answer to the question why the letter ''m'' is use ...

References

{{Taxonbar, from=Q3277045 Peristediidae Monotypic fish genera Fish described in 1917 Taxa named by Hugh McCormick Smith