Little velvetfishes or simply velvetfishes 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 ...

, the Aploactinidae, of marine ray-finned fishes classified within the order Scorpaeniformes. They are small fish that have skin with a velvet texture. They live on the sea bottom close to the shore, at depths of up to . They are found in the

Indo-Pacific The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...

region.

Taxonomy

Aploactinidae was first formally recognised as a family 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, 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

Edwin Chapin Starks Edwin Chapin Starks (born in Baraboo, Wisconsin on January 25, 1867; died December 29, 1932) was an ichthyologist most associated with Stanford University. He was known as an authority on the osteology of fish. He also did studies of fish of the ...

in 1904.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 the 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 ...

Scorpaenoidei Scorpaenoidei is a suborder of Actinopterygii, ray-finned fishes, part of the Order (biology), order Perciformes, that includes the scorpionfishes, lionfishes and velvetfishes. This suborder is at its most diverse in the Pacific and Indian Oceans ...

which in turn is classified within 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 place the Scorpaenoidei within the

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 ...

. The results of some studies suggest that the velvetfishes into an expanded stonefish clade, the family

Synanceiidae Synanceiinae is a subfamily of Venom, venomous ray-finned fishes, waspfishes, which is classification of life, classified as part of the family Scorpaenidae, the scorpionfishes and their relatives. These fishes are found in the Indo-Pacific ocean ...

because all of these fish have a curved sabre-like lacrimal spine that can project, using a switch-blade-like mechanism, out from underneath their eye. The name of the family is taken from that of the type genus, ''Aploactis''. which is a compound of "haplo" meaning "single" or "simple", and ''actis'', meaning "ray", presumed to refer to the simple, unbranched soft rays of the fins.

Genera

The following genera are classified within the family Aploactinidae: * '' Acanthosphex'' Fowler, 1938 * '' Adventor'' Whitley, 1952 * '' Aploactis''

Temminck Coenraad Jacob Temminck (; 31 March 1778 – 30 January 1858) was a Dutch patrician, zoologist and museum director. Biography Coenraad Jacob Temminck was born on 31 March 1778 in Amsterdam in the Dutch Republic. From his father, Jacob ...

& Schlegel, 1843 * '' Aploactisoma'' Castelnau, 1872 * '' Bathyaploactis'' Whitley, 1933 * '' Cocotropus'' Kaup, 1858 * '' Erisphex'' Jordan & Starks 1904 * '' Kanekonia'' Tanaka, 1915 * '' Matsubarichthys'' Poss &

Johnson Johnson may refer to: People and fictional characters *Johnson (surname), a common surname in English * Johnson (given name), a list of people * List of people with surname Johnson, including fictional characters *Johnson (composer) (1953–2011) ...

, 1991 * '' Neoaploactis'' Eschmeyer &

Allen Allen, Allen's or Allens may refer to: Buildings * Allen Arena, an indoor arena at Lipscomb University in Nashville, Tennessee * Allen Center, a skyscraper complex in downtown Houston, Texas * Allen Fieldhouse, an indoor sports arena on the Univ ...

, 1978 * '' Paraploactis'' Bleeker, 1864 * '' Peristrominous'' Whitley, 1952 * '' Prosoproctus'' Poss & Eschmeyer, 1979 * '' Pseudopataecus''

, 2004 * '' Ptarmus''

J. L. B. Smith James Leonard Brierley Smith (26 September 1897 – 8 January 1968) was a South African ichthyology, ichthyologist, organic chemist, and university professor. He was the first to identify a taxidermied fish as a coelacanth, at the time thought t ...

, 1947 * '' Sthenopus'' Richardson, 1848 * '' Xenaploactis'' Poss & Eschmeyer, 1980

Characteristics

Velvetfishes get their name from the modified, prickly scales which cover the body and give the fish a velvety appearance, although there are some species which do not have these modified scales and have smooth skin, They typically have knobby lumps on the head, although sometimes there may be sharp spines. All of the fin rays are unbranched and the spines in the

anal 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 o ...

are normally weakly developed and blunt. The

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 ...

has its origin over or nearly above the eye. The first 3 to 5 dorsal fin spines may be separate, from the rest of the dorsal fin and can be raised or have almost no membrane between them. These separate spines form a separate fin in 4 species. The

pelvic fin Pelvic fins or ventral fins are paired fins located on the ventral (belly) surface of fish, and are the lower of the only two sets of paired fins (the other being the laterally positioned pectoral fins). The pelvic fins are homologous to the hi ...

has a single spine and 2 or 3 soft rays, the

pectoral fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish aquatic locomotion, swim. Apart from the tail or caudal fin, fish fins have no direct connection with the vertebral column ...

s are very large. In most species there is a fleshy extension on the anterior

isthmus An isthmus (; : isthmuses or isthmi) is a narrow piece of land connecting two larger areas across an expanse of water by which they are otherwise separated. A tombolo is an isthmus that consists of a spit or bar, and a strait is the sea count ...

. There are no teeth on the

palatine A palatine or palatinus (Latin; : ''palatini''; cf. derivative spellings below) is a high-level official attached to imperial or royal courts in Europe since Roman Empire, Roman times.

s and no gill slit to the rear of last gill arch. One species, '' Prosoproctus pataecus'', from the

South China Sea The South China Sea is a marginal sea of the Western Pacific Ocean. It is bounded in the north by South China, in the west by the Indochinese Peninsula, in the east by the islands of Taiwan island, Taiwan and northwestern Philippines (mainly Luz ...

, uniquely among scorpaenoids has its

anus In mammals, invertebrates and most fish, the anus (: anuses or ani; from Latin, 'ring' or 'circle') is the external body orifice at the ''exit'' end of the digestive tract (bowel), i.e. the opposite end from the mouth. Its function is to facil ...

very far forward, just to the rear of the base of the pelvic fins. These are small fishes with the largest species being the roughskin scorpionfish ('' Cocotropus monacanthus'') which has a maximum published

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 .

Distribution and habitat

Velvetfishes are found mainly in the eastern Indian and western Pacific Oceans, but some species are found in the eastern Indian Ocean. The adults are found among vegetation or over rocky, shelly, coral rubble or coralline algae substrates.

Biology

Velvetfishes are uncommon and little-known. These fishes are very well camouflaged

ambush predators 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 usi ...

hiding amongst algae or rubble on or in the vicinity of rocky and coral reefs. The spines in the fin are venom bearing. Little is known about their

spawning Spawn is the Egg cell, eggs and Spermatozoa, sperm released or deposited into water by aquatic animals. As a verb, ''to spawn'' refers to the process of freely releasing eggs and sperm into a body of water (fresh or marine); the physical act is ...

behaviour but they do have pelagic

larvae A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect developmental biology, development such as insects, some arachnids, amphibians, or cnidarians typical ...

, the large pectoral fins develop early as an adaptation to their pelagic mode of life.

References

{{Taxonbar, from=Q1755617 Taxa named by David Starr Jordan Taxa named by Edwin Chapin Starks Perciformes families