''Stichodactyla mertensii'', commonly known as Mertens' carpet sea anemone, is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

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 magnifica ''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. Description The magnificent sea anemone is ...

'', which has longer tentacles. This species has an oral disc that can be described as more ovoid than circular that contours to the surrounding substrate and is attached to the substrate by adhesive verrucae, which are wart-like projections. Its blunt or pointed tentacles are uniformly shaped, and are only about long. It contains obligate symbiotic

zooxanthellae Zooxanthellae is a colloquial term for single-celled dinoflagellates that are able to live in symbiosis with diverse marine invertebrates including demosponges, corals, jellyfish, and nudibranchs. Most known zooxanthellae are in the genus ''S ...

, and is a host to around half the species of

anemonefish 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, t ...

and one

damselfish Damselfish are those within the subfamilies Abudefdufinae, Chrominae, Lepidozyginae, Pomacentrinae, and Stegastenae within the family Pomacentridae. Most species within this group are relatively small, with the largest species being about ...

, ''

Dascyllus trimaculatus The threespot dascyllus (''Dascyllus trimaculatus''), also known as the domino damsel or simply domino, is a species of damselfish from the family Pomacentridae. It is native to the Indo-Pacific from the Red Sea and East Africa, to the Pitcairn ...

''.

Distribution

''S. mertensii'' is found on rocky or coral substrate and is widespread throughout the tropical and subtropical waters of the Indo-Pacific area from

Mauritius Mauritius ( ; french: Maurice, link=no ; mfe, label= Mauritian Creole, Moris ), officially the Republic of Mauritius, is an island nation in the Indian Ocean about off the southeast coast of the African continent, east of Madagascar. It ...

to Fiji and from the

Ryukyu Islands The , also known as the or the , are a chain of Japanese islands that stretch southwest from Kyushu to Taiwan: the Ōsumi, Tokara, Amami, Okinawa, and Sakishima Islands (further divided into the Miyako and Yaeyama Islands), with Yona ...

of southern Japan to Australia. While this species can be confused with '' Stichodactyla gigantea'' and '' S. haddoni'', they are most easily distinguished by habitat since the former two prefer sand while ''S. mertensii'' prefers rocky or coral substrate.

Biology

The anemonefish generally said to be hosted by ''S. mertensii'' are: Other anemonefish said to be hosted by ''S. mertensii'' are: The relationship between anemonefish and their host sea anemones is highly

nested ''Nested'' is the seventh studio album by Bronx-born singer, songwriter and pianist Laura Nyro, released in 1978 on Columbia Records. Following on from her extensive tour to promote 1976's ''Smile'', which resulted in the 1977 live album '' Seas ...

in structure. With at least 13 species of hosted anemonefish, ''S. mertensii'' is highly generalist, and appears to be a preferred host. ''A. akallopisos'' is the only anemonefish in the

Comoro Islands The Comoro Islands or Comoros (Shikomori ''Komori''; ar, جزر القمر , ''Juzur al-qamar''; french: Les Comores) form an archipelago of volcanic islands situated off the southeastern coast of Africa, to the east of Mozambique and northwes ...

and is hosted by ''

'' and ''S. mertensii''. It appears that in the

Seychelles Seychelles (, ; ), officially the Republic of Seychelles (french: link=no, République des Seychelles; Creole: ''La Repiblik Sesel''), is an archipelagic state consisting of 115 islands in the Indian Ocean. Its capital and largest city, ...

that ''A. fuscocaudatus'' displaces ''A. akallopisos'' from ''S. mertensii'' while in the

Maldives Maldives (, ; dv, ދިވެހިރާއްޖެ, translit=Dhivehi Raajje, ), officially the Republic of Maldives ( dv, ދިވެހިރާއްޖޭގެ ޖުމްހޫރިއްޔާ, translit=Dhivehi Raajjeyge Jumhooriyyaa, label=none, ), is an archipelag ...

''A. akallopisos'' is displaced from ''S. mertensii'' by ''A. clarkii'', as in both locations ''A. akallopisos'' is only hosted by ''H. magnifica''. There are 2 specialist anemonefish that are only found with ''S. mertensii'', ''A. fuscocaudatus'' and ''A. latifasciatus''. Recently, ''

Amphiprion clarkii ''Amphiprion clarkii'', known commonly as Clark's anemonefish and yellowtail clownfish, is a marine fish belonging to the family Pomacentridae, the clownfishes and damselfishes. Characteristics of anemonefish Clownfish or anemonefish are fi ...

'' and '' Amphiprion sandaracinos'' were observed to coexist within one host anemone of ''Stichodactyla mertensii''. A. clarkii was not aggressive towards the A. sandaracinos but was aggressive towards all fish approaching the anemone. The anemonefish didn't divide the host into separate territories.

Anemonefish color variations

Some species of anemonefish, including ''A. chrysogaster'', ''A. chrysopterus'', ''A. clarkii'', ''A. percula'' and ''A. tricinctus'' have a melanistic variation when associated with anemone of the genus ''Stichodactyla''. The change in body and or fin color from orange to black can occur within hours when transferred to the anemone. The fish then changes back from black to orange when removed from the host, although the change back takes longer. Why this occurs and its benefits to either partner are unknown. Other species do not show any such variation including ''A. akallopisos'', ''A. akindynos'', ''A. allardi'', ''A. bicinctus'', ''A. fuscocaudatus'', ''A. latifasciatus'', ''A. leucokranos'' and ''A. sandaracinos''. There is a black variation of ''A. ocellaris'', however it is not known whether this is associated with any specific anemone. Image:Amphiprion clarkii.jpg, ''A. clarkii'' in a 'normal' color Image:Amphiprion clarkii Thailand.jpg, ''A. clarkii'' showing a melanistic variation

Notes

References

External links

* * {{Taxonbar, from=Q1508080 Stichodactylidae Animals described in 1835