The Platycephalidae are a

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 ...

of marine

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 ...

, most commonly referred to as flatheads. They are relatives of the

lionfish ''Pterois'' is a genus of venomous fish, venomous marine fish, commonly known as the lionfish, native to the Indo-Pacific. It is characterized by conspicuous aposematism, warning coloration with red or black bands and ostentatious dorsal fins tip ...

, and belong to the order

Perciformes Perciformes (), also called the Acanthopteri, is an order or superorder of ray-finned fish in the clade Percomorpha. ''Perciformes'' means " perch-like". Among the well-known members of this group are perches and darters ( Percidae), and als ...

Taxonomy

Platycephalidae was first proposed as a family in 1839 by the English naturalist

William Swainson William Swainson Fellow of the Linnean Society, FLS, Fellow of the Royal Society, FRS (8 October 1789 – 6 December 1855), was an English ornithologist, Malacology, malacologist, Conchology, conchologist, entomologist and artist. Life Swains ...

. 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 this family 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 ...

. Other authorities differ and do not consider the Scorpaeniformes to be a valid order because the

is not

monophyletic In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent co ...

without the taxa within the Scorpaeniformes being included within it. These authorities consider the Platycephalidae to belong to the

, along with the families

Bembridae Bembridae, the deep-water flatheads, are a family of bottom-dwelling ray-finned fishes. They are found in the Indian and western Pacific Oceans. Taxonomy Bembridae was first proposed as a family in 1873 by the German zoologist Johann Jakob Kaup ...

, Parabembridae, Hoplichthyidae and Plectrogeniidae within the Perciformes.

Genera

Platycephalidae has the following 17 genera (including about 86 species) classified within it: Platycephalidae has been divided into as many as 5

subfamilies 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 botanical subfamily names with "-oideae", and zool ...

by some authors but Fishes of the World does not recognise subfamilies but does state that some authors recognise two subfamilies. The two subfamilies are Platycephalalinae, containing ''Elates'' and ''Platycephalus'', and Onigociinae, containing the remaining genera. These two groupings are thought to have become divergent in the

Eocene The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...

with the Platycephalinae being predominantly temperate and Onigociinae, being predominantly tropical. The basal Platycephalinae species are confined to southern Australia and the more derived taxa have diversified in the tropical Indo-West Pacific. The genus '' Sorsogona'' is recognised by

Fishbase FishBase is a global species database of fish species (specifically finfish). It is the largest and most extensively accessed online database on adult finfish on the web.

but, apparently, it does not include the

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 ...

, ''Sorsogona serrulata'', as a species within it. ''

Catalog of Fishes Catalog of Fishes is a comprehensive on-line database and reference work on the scientific names of fish species and genera. It is global in its scope and is hosted by the California Academy of Sciences. It has been compiled and is continuously up ...

'' treats this genus as a

synonym A synonym is a word, morpheme, or phrase that means precisely or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are a ...

of '' Rogadius'' but classifies all the species in '' Ratabulus'', including the type species, which it treats as a synonym of '' Ratabulus tuberculatus''.

Etymology

The name of the family is derived from the

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

words ''platy'', meaning "flat", and ''kephale'' for "head".

Description

Platycephalids are small to medium-sized fish. Most species are small, reaching an average of 10 cm in length. However, a few species in the genus ''

Platycephalus ''Platycephalus'' is a genus of mostly marine, demersal ray-finned fish belonging to the family Platycephalidae. They are found in the eastern Mediterranean, the Indian Ocean and western Pacific Ocean. Taxonomy ''Platycephalus'' was first pro ...

'' are known to grow up to over a in length. Their most distinctive characteristic is the flattened shape of their heads. While the rest of their bodies is shaped similarly to other fish that inhabit the areas they frequent, their heads are triangle-shaped and dorsoventrally depressed, giving them the shape of a trowel or an artist's spatula. Their eyes are situated on the upper surface, in accordance with their bottom-dwelling lifestyle. They possess two complete

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 ...

s, the first one supported by six to 9 strong spines.

Distribution and habitat

Platycephalidae can be found naturally in coastal waters throughout the Indo-

Pacific The Pacific Ocean is the largest and deepest of Earth's five 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 bounded by the cont ...

. A few species have been caught in the eastern

Mediterranean The Mediterranean Sea ( ) is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean basin and almost completely enclosed by land: on the east by the Levant in West Asia, on the north by Anatolia in West Asia and Southern ...

, having traveled there 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 ...

through the

Suez Canal The Suez Canal (; , ') is an artificial sea-level waterway in Egypt, Indo-Mediterranean, connecting the Mediterranean Sea to the Red Sea through the Isthmus of Suez and dividing Africa and Asia (and by extension, the Sinai Peninsula from the rest ...

Biology

Flatheads are mostly 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 ...

fish, often resting directly on the

seabed The seabed (also known as the seafloor, sea floor, ocean floor, and ocean bottom) is the bottom of the ocean. All floors of the ocean are known as seabeds. The structure of the seabed of the global ocean is governed by plate tectonics. Most of ...

, sometimes partially buried in sand or mud. They can be found in a wide range of depths, ranging from 10 m to the edge of the continental shelf at depths of about . Flatheads are

carnivorous A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose nutrition and energy requirements are met by consumption of animal tissues (mainly mu ...

, feeding on small fish and

crustaceans Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of Arthropod, arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquat ...

. They lie in wait buried by sand, with only their eyes poking out from the substrate. When prospective prey walks or swims close to the platycephalid's head, the flathead strikes rapidly, engulfing the prey in its large mouth. As flatheads are

ambush predator Ambush predators or sit-and-wait predators are carnivorous animals that capture their prey via stealth, luring or by (typically instinctive) strategies utilizing an element of surprise. Unlike pursuit predators, who chase to capture prey u ...

s they are expected to be relatively sedentary and not move large distances as adults. However, recent research has shown that part of the population of some flathead species makes long-distance movements or spawning migrations.

Fisheries

Active commercial fisheries are geared towards members of the family. In

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

, some species are the subject of experimental

aquaculture Aquaculture (less commonly spelled aquiculture), also known as aquafarming, is the controlled cultivation ("farming") of aquatic organisms such as fish, crustaceans, mollusks, algae and other organisms of value such as aquatic plants (e.g. Nelu ...

programs. Flatheads are commonly caught on rod and line. The larger species are considered game fish.

References

* *

External links

*
Photos of several species of Crocodilefishes
{{Authority control Fish of the Pacific Ocean Perciformes families Taxa named by William Swainson