Clark's anemonefish (''Amphiprion clarkii''), also known as the yellowtail clownfish, is a

marine fish Saltwater fish, also called marine fish or sea fish, are fish that live in seawater. Saltwater fish can swim and live alone or in a large group called a school. Saltwater fish are very commonly kept in aquariums for entertainment. Many saltwater ...

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 ...

Pomacentridae Pomacentridae is a family of ray-finned fish, comprising the damselfishes and clownfishes. This family were formerly placed in the order Perciformes or as indeterminate percomorphs, but are now considered basal blenniiforms. They are primaril ...

, the

clownfish Clownfishes or anemonefishes (genus ''Amphiprion'') are saltwater fishes found in the warm and tropical waters of the Indo-Pacific. They inhabit mainly coral reefs and have a distinctive colouration typically consisting of white vertical bars on ...

es and

damselfish Damselfish are those fish within the subfamilies Abudefdufinae, Chrominae, Lepidozyginae, Pomacentrinae, and Stegastinae within the family Pomacentridae. Most species within this group are relatively small, although the four largest speci ...

es. 28 species of anemonefish live within the Pomacentridae family (Steer P. 2012).

Characteristics of anemonefish

Clownfish or anemonefish are

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

es that, in the wild, form

symbiotic Symbiosis (Ancient Greek : living with, companionship < : together; and ''bíōsis'': living) is any type of a close and long-term biolo ...

mutualism Mutualism may refer to: * Mutualism (biology), positive interactions between species * Mutualism (economic theory), associated with Pierre-Joseph Proudhon * Mutualism (movement), social movement promoting mutual organizations * Mutualism model o ...

s with

sea anemone Sea anemones ( ) are a group of predation, predatory marine invertebrates constituting the order (biology), order Actiniaria. Because of their colourful appearance, they are named after the ''Anemone'', a terrestrial flowering plant. Sea anemone ...

s and are unaffected by the stinging tentacles of the host anemone, see . The sea anemone protects the clownfish from predators, as well as providing food through the scraps left from the anemone's meals and occasional dead anemone tentacles. In return, the clownfish defends the anemone from its predators, and parasites. Anemonefish tend to have a life span of about 10-11 years when accounting for a predictable environment that does not experience much change in water temperature, increase in predation or habitat degradation (Lakshmi Sawitri). Clownfish are small-sized, , and depending on species, they are overall yellow, orange, or a reddish or blackish color, and many show white bars or patches. Within species there may be color variations, most commonly according to distribution, but also based on sex, age and host anemone. Clownfish are found in warmer waters of the

Indian Indian or Indians may refer to: Associated with India * of or related to India ** Indian people ** Indian diaspora ** Languages of India ** Indian English, a dialect of the English language ** Indian cuisine Associated with indigenous peoples o ...

and

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 ...

oceans and 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 ...

in sheltered

reef A reef is a ridge or shoal of rock, coral, or similar relatively stable material lying beneath the surface of a natural body of water. Many reefs result from natural, abiotic component, abiotic (non-living) processes such as deposition (geol ...

s or in shallow

lagoon A lagoon is a shallow body of water separated from a larger body of water by a narrow landform, such as reefs, barrier islands, barrier peninsulas, or isthmuses. Lagoons are commonly divided into ''coastal lagoons'' (or ''barrier lagoons'') an ...

s. In a group of clownfish, there is a strict

dominance hierarchy In the zoological field of ethology, a dominance hierarchy (formerly and colloquially called a pecking order) is a type of social hierarchy that arises when members of animal social animal, social groups interact, creating a ranking system. Dif ...

. The largest and most aggressive fish is female and is found at the top. Only two clownfish, a male and a female, in a group reproduce through

external fertilization External fertilization is a mode of reproduction in which a male organism's sperm fertilizes a female organism's egg outside of the female's body. It is contrasted with internal fertilization, in which sperm are introduced via insemination and then ...

. Clownfish are

sequential hermaphrodites Sequential hermaphroditism (called dichogamy in botany) is one of the two types of hermaphroditism, the other type being simultaneous hermaphroditism. It occurs when the organism's sex changes at some point in its life. A sequential hermaphrodite ...

, meaning that they develop into males first, and when they mature, they become females. They are not aggressive. When the egg production and spawning patterns of eight breeding pairs were observed in a coral reef off the coast of the Philippines, they preferred breeding in the colder months. A trend of a peak breeding season from November through May was seen; egg production increased up to the new moon and decreased after the full moon. This seasonality of spawning is comparable to other species of clownfish that live in temperate regions.

Description

Clark's anemonefish is a small-sized

which grows up to as a male and as a female. It is stocky, laterally compressed, and oval to rounded. It is colorful, with vivid black, white, and yellow stripes, though the exact pattern shows considerable geographical variation. Usually it is black dorsally and orange-yellow ventrally, the black areas becoming wider with age. There are two vertical white bands, one behind the eye and one above the anus, and the

caudal peduncle 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 ...

is white. The

snout A snout is the protruding portion of an animal's face, consisting of its nose, mouth, and jaw. In many animals, the structure is called a muzzle, Rostrum (anatomy), rostrum, beak or proboscis. The wet furless surface around the nostrils of the n ...

is orange or pinkish. The

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage The fus ...

and

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 ...

s are orange-yellow, and the caudal fin is generally lighter in tone than the rest of the body, sometimes becoming whitish.

Color variations

Clark's anemonefish shows the greatest color variations of any anemonefish, with variations based on location, sex, age and host anemone. Adults in

Vanuatu Vanuatu ( or ; ), officially the Republic of Vanuatu (; ), is an island country in Melanesia located in the South Pacific Ocean. The archipelago, which is of volcanic origin, is east of northern Australia, northeast of New Caledonia, east o ...

and

New Caledonia New Caledonia ( ; ) is a group of islands in the southwest Pacific Ocean, southwest of Vanuatu and east of Australia. Located from Metropolitan France, it forms a Overseas France#Sui generis collectivity, ''sui generis'' collectivity of t ...

are orange-yellow with two vertical white bands. Sex related color differences may be present, such as the female having a white caudal fin and the male having a yellow caudal fin. Juveniles are orange-yellow with vertical white bands. Fish living with the host anemone ''

Stichodactyla mertensii ''Stichodactyla mertensii'', commonly known as Mertens' carpet sea anemone, is a species of sea anemones in the family Stichodactylidae. It is regarded as the largest sea anemone with a diameter of over , the next largest being '' Heteractis mag ...

'', Mertens' carpet sea anemone are frequently black except for the snout bars and tail.

Similar species of ''Amphiprion''

The caudal fin is forked and the base lacks a white bar on '' A. latifasciatus''. The caudal fin lacks the sharp demarcation between white and dark and the mid-body bar is narrower on '' A. allardi'' and '' A. akindynos''. The caudal fin is dark on '' A. chrysogaster'', '' A. fuscocaudatus'' and '' A. tricinctus''.

Distribution and habitat

Clark's anemonefish is the most widely distributed anemonefish, being found in

tropical The tropics are the regions of Earth surrounding the equator, where the sun may shine directly overhead. This contrasts with the temperate or polar regions of Earth, where the Sun can never be directly overhead. This is because of Earth's ax ...

waters from the Indian Ocean to the Western Pacific. These anemonefish most commonly occupy reef biomes at 1 to 60 meters in areas with host anemones (Moore, Billy).

Host anemones

Clark's anemonefish is the least host specific anemonefish, living in association with all ten

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of sea anemones that host anemonefish: *'' Cryptodendrum adhaesivum'' *''

Entacmaea quadricolor Bubble-tip anemone (''Entacmaea quadricolor'') is a species of sea anemone in the family Actiniidae. Like several anemone species, ''E. quadricolor'' can support several anemonefish species, and displays two growth types based on where they ...

'' Bubble-tip anemone *''

Heteractis aurora ''Heteractis aurora'' is a species of sea anemone in the family Heteractidae. Taxonomy Common names for ''H. aurora'' include beaded sea anemone, aurora host anemone, sand anemone, carpet anemone, flat anemone, corn anemone, Ritteri anemone, ...

'' beaded sea anemone *''

Heteractis crispa The sebae anemone (''Radianthus crispa''), also known as leathery sea anemone, long tentacle anemone, or purple tip anemone, is a species of sea anemone in the family Stichodactylidae and native to the Indo-Pacific. It was first described in 183 ...

'' Sebae anemone *''

Heteractis magnifica ''Radianthus magnifica'', also known by as magnificent sea anemone or Ritteri anemone, is a species of sea anemone in the family Stichodactylidae that is native to the Hawaii, USA, Indo-Pacific. Description The magnificent sea anemone is chara ...

'' magnificent sea anemone *'' Heteractis malu'' delicate sea anemone *'' Macrodactyla doreensis'' long tentacle anemone *''

Stichodactyla gigantea ''Stichodactyla gigantea'', commonly known as the giant carpet anemone, is a species of sea anemone that lives in the Hawaii, USA, North America, and Indo-Pacific area. It can be kept in an aquarium but is a very challenging species to keep aliv ...

'' giant carpet anemone *''

Stichodactyla haddoni ''Stichodactyla haddoni'', commonly known as Haddon's sea anemone, is a species of sea anemone belonging to the family Stichodactylidae. It is found in the Indo-Pacific area. Description ''S. haddoni'' is characterized by a folded oral disc that ...

'' *''

'' Mertens' carpet sea anemone

Etymology

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 ...

and the

common name In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often con ...

both honour the

Scottish Scottish usually refers to something of, from, or related to Scotland, including: *Scottish Gaelic, a Celtic Goidelic language of the Indo-European language family native to Scotland *Scottish English *Scottish national identity, the Scottish ide ...

engraver John Heaviside Clark (1771–1836) who provided illustrations for Bennett's ''A Selection from the most remarkable and interesting Fishes found on the Coast of Ceylon, from drawings made in the Southern part of that Island''.

References

External links

* {{Taxonbar, from=Q275239 Amphiprion Fish described in 1830