Ocellaris clownfish

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Ocellaris clownfish
Amphiprion ocellaris (1).jpg
Specimen from the Wrocław Zoo
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Family: Pomacentridae
Genus: Amphiprion
Species:
A. ocellaris
Binomial name
Amphiprion ocellaris
Cuvier, 1830 [2]
Synonyms

Amphiprion bicolor Castelnau, 1873
Amphiprion melanurusCuvier, 1830

Contents

The ocellaris clownfish (Amphiprion ocellaris), also known as the false percula clownfish or common clownfish, is a marine fish belonging to the family Pomacentridae, which includes clownfishes and damselfishes. Amphiprion ocellaris are found in different colors, depending on where they are located. For example, black Amphiprion ocellaris with white bands can be found near northern Australia, Southeast Asia, and Japan. [3] Orange or red-brown Amphiprion ocellaris also exist with three similar white bands on the body and head. Amphiprion ocellaris can be distinguished from other Amphiprion species based on the number of pectoral rays and dorsal spines. Amphiprion ocellaris are known to grow about 11 cm (4.3 inches) long. [4] Like many other fish species, females are, however, larger than males. [3] The life cycle of Amphiprion ocellaris varies in whether they reside at the surface or bottom of the ocean. When they initially hatch, they reside near the surface. However, when Amphiprion ocellaris enter into the juvenile stage of life, they travel down to the bottom to find shelter in a host anemone. [5] Once they find their anemone, they form a symbiotic relationship with them. [3] [6]

Phylogeny

Purple anemone (Heteractis magnifica) and resident anemonefish (Amphiprion ocellaris) in East Timor Anemone purple anemonefish.jpg
Purple anemone ( Heteractis magnifica ) and resident anemonefish (Amphiprion ocellaris) in East Timor

The species Amphiprion ocellaris belongs to the class Actinopterygii which contains bony Teleost fish and other ray-finned fish. A. ocellaris is the most basal species in the genus Amphiprion which is closely related to the genus Premnas . The species' most closely related ancestor is Amphiprion percula , the orange clownfish. It is thought that A. ocellaris specialized after diverging from the genus Premnas, and scientific evidence confirms that all clownfish belonging to the genus Amphiprion initially could withstand the stings of only one type of anemone; after further speciation the 28 different species of clownfish including A. ocellaris have specialized to be able to resist the poisonous stings of many different anemone species.

Description

The common clownfish is a small fish which grows up to 11 cm (4.3 inches). [4] Its body has a stocky appearance and oval shape. It is compressed laterally, with a round profile. The coloration of its body is orange to reddish-brown, but it can also be black in some particular areas such as the Northern Territory in Australia. [7] [8] It has three vertical white stripes outlined with a fine black line. The first passes just behind the eye, the second in the middle of the body widens forward to the head centrally and the third one circles the caudal peduncle. [4] All the fins are also outlined with a fine black line. A. ocellaris is often confused with Amphiprion percula, which possesses exactly the same colours and patterns at first sight but distinguishes itself by the thickness of the black outlines. [9] Additionally, A. ocellaris has a taller dorsal fin, and typically possesses 11 dorsal-fin spines vs. 10 spines in Amphiprion percula. [10]

Distribution and habitat

This species is found in the Eastern Indian Ocean and in the western Pacific Ocean. [4] As mentioned earlier, they can also be found in Northern Australia, Southeast Asia and Japan. [3]

Amphiprion ocellaris typically lives in small groups on outer reef slopes or in sheltered lagoons at a maximal depth of 15 meters. It inhabits three different species of sea anemones: Heteractis magnifica , Stichodactyla gigantea and Stichodactyla mertensii and have symbiotic relationships with the anemone. [3] [6] [11]

Behavior

Amphiprion ocellaris is a diurnal fish. It is a protandrous hermaphrodite, which means the male can change its sex to female during its life, and lives in a harem in which an established dominance hierarchy manages the group and keeps individuals at a specific social rank. It is aggressively territorial and is completely dependent on its sea anemone. [11]

Shelter

Amphiprion ocellaris are reliant on sea anemone for shelter (they have a symbiotic relationship with the sea anemone). Sea anemone are protection for the fish and their nests. This is because when A. ocellaris are in the open waters, they have a higher risk of predation. It is postulated that the fanning behavior of the fish and removal of parasites promotes the health of sea anemones which contain A. ocellaris fish. In addition, the anemone provides protection for the fish with its tentacles, however, the fish's mucus protection prevents it from being stung by the tentacles. [3] [6] The presence of the clownfish can be interpreted as a lure to attract potential anemone's preys close to the tentacles. And the clownfish can also defend the anemone against some reef fishes which could eat the tentacles. [11]

Social system

Ocellaris clownfish in the National Marine Aquarium, Plymouth

Social systems can be defined as society considered as a system organized by a characteristic pattern of relationships. [12] A. ocellaris form specific social hierarchies within their societies. These social hierarchies result in competition to travel between the different levels of society, which is seen between various ages as well.

Queue selection

Queues is the term for social groups of A. ocellaris. This is because these fish form social hierarchies, or social rank, by outliving the more dominant members of the group. The dominant pair of each queue reproduces more compared to the subordinate fishes. This is the reason for why these individuals should adopt various tactics in which they increase their probability of attaining social dominance. There are two types of A. ocellaris, settlers and switchers. Settlers prefer shorter queues, while switchers will usually move after settlement. However, studies show that there is no difference in the characteristics between switchers and non-switchers, and there is no data demonstrating that A. ocellaris utilize the switching tactic for dominance. Although settlement preferences increase the likelihood of gaining social dominance, switching could have the function of increasing social dominance benefits after social dominance has been acquired. [13]

Juvenile Amphiprion ocellaris

Juvenile A. ocellaris have difficulty finding a sea anemone to live in (since they need anemone for survival and shelter). The difficulty also arises in the fact that there exists a hierarchy in each anemone. Thus, when a new juvenile enters an anemone, it begins at the bottom of the social ladder where it is often the victim of aggression by other clownfish. This aggression from other A. ocellaris in the anemone can cause the juvenile to be chased out of the anemone, and left to search for another anemone. [5] [6] [14] [15]

Group size and patch size

Studies have shown that there is a correlation between the size of the group and the size of the patch; however this correlation provides no implication that subordinate group members have less resources. More likely, it is the effects of the patch size on the group member that dominates interactions. An experiment was performed to study the mechanism responsible for the positive correlation between the group size and patch size. The scientists argued that the correlation between the group size and patch size is because of the indirect consequence of the positive relationship between the dominant group member's length and the anemone size. The length of the dominant group member limits the group size because the length of the dominant group member prevents the group of the subordinate group members. This data shows that the patch size and group size correlation does not necessarily imply the decrease in resources of group members subordinate to the dominant group member. [16]

Food habits

Amphiprion ocellaris feed on plankton and algae, thus they are considered omnivores. Feeding is also affected by the hierarchy in A. ocellaris groups. Since the smaller, less dominant fish face aggression from the more aggressive fish, they have less energy to forage for food. Thus, they usually do not eat as much as the dominant fish do, because of reduced energy, but also because of the increased danger they face when they leave their anemone since they are smaller. In other words, the larger fish will usually travel farther than the smaller fish. Generally, the A. ocellaris feed on algae, copepods, and zooplankton. [5] [15] [17]

Reproduction and life history

Amphiprion ocellaris have reproductive behaviors very similar to that of all anemonefish. They have monogamous mating systems, and in their spawning processes, they also have the same levels of aggressiveness between males and females. In addition, there is a reproductive hierarchy that exists between age and sex.

Clownfish are initially male; the largest fish in a group becomes female. Ocellaris clownfish.JPG
Clownfish are initially male; the largest fish in a group becomes female.

Spawning

There is not much data on the reproduction of A. ocellaris. However, similar behaviors throughout all anemone fishes have been recorded. These fish have monogamous mating systems, and are territorial of their anemone. Males become more aggressive during spawning. Male behavior also changes to attract females: biting, chasing, fin extension. Before spawning, the male prepares the nest near the anemone (so that the tentacles of the anemone can protect the nest). After the male chases the female to the nest, the female begins the spawning process. She lays eggs for about one to two hours, and then leave the nest for the male to fertilize the eggs. The eggs take approximately six to eight days to hatch (this time period can be affected by the temperature of water). Because of the external fertilization, males usually care for the eggs. They also have responsibilities for eating fungi-infected or infertile eggs, and fanning the eggs. [5] [15]

Reproductive hierarchy

The males can change sex to female during their lives, and live in a harem in which an established dominance hierarchy manages the group and keeps individuals at a specific social rank. Amphiprion ocellaris (Clown anemonefish) Nemo.jpg
The males can change sex to female during their lives, and live in a harem in which an established dominance hierarchy manages the group and keeps individuals at a specific social rank.

All anemonefish are protandrous hermaphrodites, meaning they first develop into males and may become females later in life. Anemonefish exhibit phenotypic plasticity when males, females, and juveniles inhabit the same anemone. In an anemonefish social group, the female is the dominant and largest member, followed by the dominant male, while other anemonefish remain non-reproductive. [18]

One experiment placed three juvenile anemonefish in a tank and observed their behaviors over the course of a month. The researchers drew conclusions about the fish's social hierarchy based on signs of dominance such as aggressive or appeasing behaviors, occupation of territory in the tank, and body mass increase. The dominant fish grew larger compared to lower-ranked fish, suggesting the lower-ranked fish experienced growth suppression. In addition, a difference in the fish's levels of certain steroids suggested that lower-ranked individuals also experienced reproductive suppression. [19]

Another experiment demonstrated that when a female anemonefish is removed from the anemone, then the dominant male becomes the female and the next-highest-ranked male moves up the dominance hierarchy to become the dominant male. Females use aggressive dominance behavior to control the males, preventing the formation of other females, and dominant males prevent juvenile males from mating. [18]

In aquaria

In nature, the false percula clownfish is hosted by Heteractis magnifica and Stichodactyla gigantea. However, in captivity in a reef aquarium, the false percula is hosted by other species of anemone, including Entacmaea quadricolor . In addition, clownfish may adopt a surrogate host as opposed to an anemone, such as Euphyllia divisa , xenia coral, etc.

Human interaction

Amphiprion ocellaris are utilized as part of the tropical fish aquarium trade. However, only certain colors are in demand. In addition, A. ocellaris are used in research since they can be bred easily. [20] This high demand in trade has been dangerous for A. ocellaris' population due to overexploitation [ citation needed ].

The main characters Marlin and his son Nemo from the animated film Finding Nemo , and its sequel Finding Dory (as well as his late wife Coral), are ocellaris clownfish.

Related Research Articles

<span class="mw-page-title-main">Clownfish</span> Subfamily of fishes

Clownfish or anemonefish are fishes from the subfamily Amphiprioninae in the family Pomacentridae. Thirty species of clownfish are recognized: one in the genus Premnas, while the remaining are in the genus Amphiprion. In the wild, they all form symbiotic mutualisms with sea anemones. Depending on the species, anemonefish are overall yellow, orange, or a reddish or blackish color, and many show white bars or patches. The largest can reach a length of 17 cm, while the smallest barely achieve 7–8 cm.

<span class="mw-page-title-main">Orange clownfish</span> Species of fish

The orange clownfish also known as percula clownfish and clown anemonefish, is widely known as a popular aquarium fish. Like other clownfishes, it often lives in association with sea anemones. A. percula is associated specifically with Heteractis magnifica and Stichodactyla gigantea, and as larvae use chemical cues released from the anemones to identify and locate the appropriate host species to use them for shelter and protection. This causes preferential selection when finding their anemone host species. Although popular, maintaining this species in captivity is rather complex. The Great Barrier Reef Marine Park Authority regulates the number of collection permits issued to aquarium fish dealers who seek this, and other tropical fish within the Great Barrier Reef Marine Park. The symbiosis between anemonefish and anemones depends on the presence of the fish drawing other fish to the anemone, where they are stung by its venomous tentacles. The anemone helps the fish by giving it protection from predators, which include brittle stars, wrasses, and other damselfish, and the fish helps the anemone by feeding it, increasing oxygenation, and removing waste material from the host. Various hypotheses exist about the fish's ability to live within the anemone without being harmed. One study carried out at Marineland of the Pacific by Dr. Demorest Davenport and Dr. Kenneth Noris in 1958 revealed that the mucus secreted by the anemone fish prevented the anemone from discharging its lethal stinging nematocysts. A second hypothesis is that A. percula has acquired immunity towards the sea anemone's toxins, and a combination of the two has been shown to be the case. The fish feed on algae, zooplankton, worms, and small crustaceans.

<span class="mw-page-title-main">Clark's anemonefish</span> Species of fish

Clark's anemonefish, also known as the yellowtail clownfish, is a marine fish belonging to the family Pomacentridae, the clownfishes and damselfishes.

<i>Heteractis magnifica</i> Species of sea anemone

Heteractis magnifica, also known by the common names magnificent sea anemone or Ritteri anemone, is a species of sea anemone belonging to the Stichodactylidae family native to the Indo-Pacific area.

<span class="mw-page-title-main">Tomato clownfish</span> Species of fish

The tomato clownfish is a species of marine fish in the family Pomacentridae, the clownfishes and damselfishes. It is native to the waters of the Western Pacific, from the Japan to Indonesia. Other common names include blackback anemonefish, bridled anemonefish, fire clown, and red tomato clown.

<span class="mw-page-title-main">Orange skunk clownfish</span> Species of fish

Amphiprion sandaracinos, also known as the orange skunk clownfish or orange anemonefish, is a species of anemonefish that is distinguished by its broad white stripe along the dorsal ridge. Like all anemonefishes it forms a symbiotic mutualism with sea anemones and is unaffected by the stinging tentacles of the host anemone. It is a sequential hermaphrodite with a strict sized based dominance hierarchy: the female is largest, the breeding male is second largest, and the male non-breeders get progressively smaller as the hierarchy descends. They exhibit protandry, meaning the breeding male will change to female if the sole breeding female dies, with the largest non-breeder becomes the breeding male.

<span class="mw-page-title-main">Orange-fin anemonefish</span> Species of fish

The orange-fin anemonefish is a marine fish belonging to the family Pomacentridae, the clownfishes and damselfishes, found in the Western Pacific north of the Great Barrier Reef from the surface to 20 m, to include the Pacific Ocean between Queensland, Australia, and New Guinea to the Marshall and Tuamotus Islands. It can grow to 17 cm in length.

<span class="mw-page-title-main">Allard's clownfish</span> Species of fish

Allard's clownfish or Allard's anemonefish is a marine fish belonging to the family Pomacentridae, the clownfishes and damselfishes, from the western Indian Ocean off the coast of East Africa and the Mascarenes.

<span class="mw-page-title-main">Saddleback clownfish</span> Species of fish

Amphiprion polymnus, also known as the saddleback clownfish or yellowfin anemonefish, is a black and white species of anemonefish with a distinctive saddle. Like all anemonefishes it forms a symbiotic mutualism with sea anemones and is unaffected by the stinging tentacles of the host anemone. It is a sequential hermaphrodite with a strict sized-based dominance hierarchy: the female is largest, the breeding male is second largest, and the male non-breeders get progressively smaller as the hierarchy descends. They exhibit protandry, meaning the breeding male will change to female if the sole breeding female dies, with the largest non-breeder becomes the breeding male.

<i>Amphiprion akindynos</i> Species of fish

Amphiprion akindynos, the Barrier Reef anemonefish, is a species of anemonefish that is principally found in the Great Barrier Reef of Australia, but also in nearby locations in the Western Pacific. The species name 'akindynos' is Greek, meaning 'safe' or 'without danger' in reference to the safety afforded amongst the tentacles of its host anemone. Like all anemonefishes it forms a symbiotic mutualism with sea anemones and is unaffected by the stinging tentacles of the host anemone. It is a sequential hermaphrodite with a strict size-based dominance hierarchy: the female is largest, the breeding male is second largest, and the male non-breeders get progressively smaller as the hierarchy descends. They exhibit protandry, meaning the breeding male will change to female if the sole breeding female dies, with the largest non-breeder becomes the breeding male. The fish's natural diet includes zooplankton.

<span class="mw-page-title-main">Red Sea clownfish</span> Species of fish

The Red Sea Clownfish, commonly known as the Red Sea or two-bandedanemonefish is a marine fish belonging to the family Pomacentridae, the clownfishes and damselfishes. Like other species of the genus, the fish feeds on algae and zooplankton in the wild.

<span class="mw-page-title-main">Pink skunk clownfish</span> Species of fish

The pink skunk clownfish, also known as the pink anemonefish, is a species of anemonefish that is widespread from northern Australia through the Malay Archipelago and Melanesia. Like all anemonefishes, it forms a symbiotic mutualism with sea anemones and is unaffected by the stinging tentacles of the host. It is a sequential hermaphrodite with a strict size-based dominance hierarchy; the female is largest, the breeding male is second largest, and the male nonbreeders get progressively smaller as the hierarchy descends. They exhibit protandry, meaning the breeding male changes to female if the sole breeding female dies, with the largest nonbreeder becoming the breeding male.

<span class="mw-page-title-main">Red saddleback anemonefish</span> Species of fish

The red saddleback anemonefish, Amphiprion ephippium, also known as the saddle anemonefish, is a marine fish belonging to the family Pomacentridae, the clownfishes and damselfishes.

<span class="mw-page-title-main">Three-band anemonefish</span> Species of fish

The three-band anemonefish is a species of anemonefish endemic to the Marshall Islands in the western part of the Pacific Ocean. Like all anemonefishes, it forms a symbiotic mutualism with sea anemones and is unaffected by the stinging tentacles of its host. It is a sequential hermaphrodite with a strict size-based dominance hierarchy; the female is largest, the breeding male is second largest, and the male nonbreeders get progressively smaller as the hierarchy descends. They exhibit protandry, meaning the breeding male changes to female if the sole breeding female dies, with the largest nonbreeder becoming the breeding male. The fish's natural diet includes zooplankton.

<i>Amphiprion akallopisos</i> Species of fish

The nosestripe clownfish or nosestripe anemonefish, skunk clownfish, Amphiprion akallopisos, is an anemonefish that lives in association with sea anemones. A. akallopisos is found in the Indian Ocean. It resides in shallow inshore reefs as deep as 15 m with a moderate to strong current. The skunk clownfish can also be kept in captivity by aquarists.

<i>Stichodactyla gigantea</i> Species of sea anemone

Stichodactyla gigantea, commonly known as the giant carpet anemone, is a species of sea anemone that lives in the Indo-Pacific area. It can be kept in an aquarium but is a very challenging species to keep alive and healthy for more than 3–5 years.

<i>Amphiprion chagosensis</i> Species of fish

Amphiprion chagosensis, the Chagos anemonefish, is a marine fish belonging to the family Pomacentridae, the clownfishes and damselfishes. It is named for the Chagos Archipelago in the Indian Ocean and it is endemic to the archipelago. The original specimens were collected at Diego Garcia Atoll, Chagos Archipelago.

<i>Amphiprion chrysogaster</i> Species of fish

Amphiprion chrysogaster, the Mauritian anemonefish, is a marine fish belonging to the family Pomacentridae, the clownfishes and damselfishes. It is endemic to Mauritius and probably Réunion.

<i>Amphiprion leucokranos</i> Species of fish

Amphiprion leucokranos is a naturally occurring hybrid anemonefish found in the western central Pacific Ocean. Like all anemonefishes it forms a symbiotic mutualism with sea anemones and is unaffected by the stinging tentacles of the host anemone. It is a sequential hermaphrodite with a strict dominance hierarchy, features which are critical to the direction of gene flow.

Amphiprion thiellei is thought to be a naturally occurring hybrid anemonefish found in the vicinity of Cebu, Philippines. Like all anemonefishes it forms a symbiotic mutualism with sea anemones and is unaffected by the stinging tentacles of the host anemone. It is a sequential hermaphrodite with a strict dominance hierarchy.

References

  1. ↑ Allen, G.R.; Arceo, H.; Mutia, M.T.M.; Muyot, F.B. & Nañola, C.L. & Santos (2022). "Amphiprion ocellaris". IUCN Red List of Threatened Species . 2022: e.T188321A1857718. doi: 10.2305/IUCN.UK.2022-2.RLTS.T188321A1857718.en . Retrieved 9 December 2022.
  2. ↑ Bailly, N. (2010). Bailly N (ed.). "Amphiprion ocellaris Cuvier, 1830". FishBase . World Register of Marine Species . Retrieved 2011-12-19.
  3. 1 2 3 4 5 6 Allen, G. 1997. Marine Fishes of Tropical Australia and South-East Asia. Perth: Western Australian Museum.
  4. 1 2 3 4 "Amphiprion ocellaris". Encyclopedia of Life. Retrieved 12 September 2016.
  5. 1 2 3 4 Fautin, Daphne G.; Allen, Gerald R. (1997). Field Guide to Anemone Fishes and Their Host Sea Anemones. Western Australian Museum. ISBN   9780730983651. Archived from the original on 10 January 2015.
  6. 1 2 3 4 Myers, R. 1999. Miconesian Reef Fish: A Field Guide for Divers and Aquarists. Barrigada: Territory of Guam: Coral Graphics.
  7. ↑ Allen, Marine Fishes of Tropical Australia and South-East Asia,Western Australian Museum,1997, ISBN   9780730987512
  8. ↑ Froese, Rainer; Pauly, Daniel (eds.) (2014). "Amphiprion ocellaris" in FishBase. November 2014 version.
  9. ↑ Vilcinskas, Andreas (2002). La vie sous-marine des tropiques[Marine life of the tropics] (in French). Paris: Vigot. ISBN   2-7114-1525-2.
  10. ↑ "Dianne J. Bray, 2011, Western Clown Anemonefish, Amphiprion ocellaris, in Fishes of Australia, accessed 25 Aug 2014".
  11. 1 2 3 Newcomb, Dani. "Amphiprion ocellaris (Clown anemonefish)". Animal Diversity Web.
  12. ↑ "social system". TheFreeDictionary.com.
  13. ↑ Mitchell, Jeremy. "Queue Selection and Switching by False Clown Anemonefish, Amphiprion Ocellaris." Animal Behavior 69 (2005): 643-52. Science Direct. Web.
  14. ↑ Arvedlund, M., L. Nielsen. 1996. Do the anemonefish Amphiprion ocellaris (Pisces: Pomacentridae) imprint themselves to their host sea anemone Heteractis magnifica (Athozoa: Actinidae)?. Ethology, 102: 197-211.
  15. 1 2 3 Thresher, R. 1984. Reproduction in Reef Fishes. New Jersey: T.F.H. Publications, Inc.
  16. ↑ J.S. Mitchell1,2 and L.M. Dill. Behavioural Ecology Research Group, Department of Biological Sciences, Simon Fraser University, Burnaby, BC V5A 1S6, Canada.
  17. ↑ Sano, M., M. Shimizu, Y. Nose. 1984. Food habits of teleostean reef fishes in Okinawa Island, Southern Japan. Japan: University of Tokyo Press.
  18. 1 2 Fricke, H., S. Fricke. 1977. Monogamy and sex change by aggressive dominance in coral reef fish. Nature, 266: 830-832.
  19. ↑ Iwata, Eri, Yukiko Nagai, Mai Hyoudou, and Hideaki Sasaki. "Social Environment and Sex Differentiation in the False Clown Anemonefish, Amphiprion ocellaris." Zoological Science 25.2 (2008): 123-28. Print.
  20. ↑ Sadovy, Y., A. Vincent (2002). "Ecological Issue and the Trade in Live Reef Fishes". pp. 395 in P Sale, ed. Coral Reef Fishes. San Diego, California: Academic Press.
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