''Thor amboinensis'', commonly known as the squat shrimp or sexy shrimp, 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 shrimp found across the

Indo-West 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 ...

and in parts of the

Atlantic Ocean The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...

. It lives

symbiotically Symbiosis (from Greek , , "living together", from , , "together", and , bíōsis, "living") is any type of a close and long-term biological interaction between two different biological organisms, be it mutualistic, commensalistic, or parasit ...

coral Corals are marine invertebrates within the class Anthozoa of the phylum Cnidaria. They typically form compact colonies of many identical individual polyps. Coral species include the important reef builders that inhabit tropical oceans and ...

s, sea anemones and other marine invertebrates in shallow reef communities.

Description

''Thor amboinensis'' is a small shrimp growing to a length of about . It is an olive brown colour with symmetrically placed white patches edged with thin blue lines. It characteristically carries its abdomen curved upwards with its tail fan above its head.

Distribution

Though it is named for Ambon or Amboyna Island, one of the

Maluku Islands The Maluku Islands (; Indonesian: ''Kepulauan Maluku'') or the Moluccas () are an archipelago in the east of Indonesia. Tectonically they are located on the Halmahera Plate within the Molucca Sea Collision Zone. Geographically they are located ...

in Indonesia, ''Thor amboinensis'' has a pantropical distribution being found in the Red Sea, the Indian Ocean, the Pacific Ocean, the Caribbean Sea, the Gulf of Mexico, Madeira and the Canary Islands.

Ecology

''Thor amboinensis'' forms a

commensal Commensalism is a long-term biological interaction (symbiosis) in which members of one species gain benefits while those of the other species neither benefit nor are harmed. This is in contrast with mutualism, in which both organisms benefit fro ...

relationship with another invertebrate, usually a shallow water sea anemone or

mushroom coral The Fungiidae () are a family of Cnidaria, commonly known as mushroom corals or plate corals. The family contains thirteen extant genera. They range from solitary corals to colonial species. Some genera such as ''Cycloseris'' and '' Fungia'' ar ...

. The species most often used as host in

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include the 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 t ...

''), the stinging anemone ('' Lebrunia danae'') and the adhesive anemone ('' Cryptodendrum adhaesivum''). One or several shrimps live among the

tentacle In zoology, a tentacle is a flexible, mobile, and elongated organ present in some species of animals, most of them invertebrates. In animal anatomy, tentacles usually occur in one or more pairs. Anatomically, the tentacles of animals work ma ...

s of their host, feeding on the tentacle tissue and on the mucus-trapped

plankton Plankton are the diverse collection of organisms found in water (or air) that are unable to propel themselves against a current (or wind). The individual organisms constituting plankton are called plankters. In the ocean, they provide a crucia ...

ic particles adhering to it. In the

Bahamas The Bahamas (), officially the Commonwealth of The Bahamas, is an island country within the Lucayan Archipelago of the West Indies in the North Atlantic. It takes up 97% of the Lucayan Archipelago's land area and is home to 88% of the ar ...

, ''Thor amboinensis'' forms part of an assemblage of symbiotic invertebrates associated with the anemone ''Lebrunia danae''. Each shrimp, crab and

brittle star Brittle stars, serpent stars, or ophiuroids (; ; referring to the serpent-like arms of the brittle star) are echinoderms in the class Ophiuroidea, closely related to starfish. They crawl across the sea floor using their flexible arms for locomot ...

inhabits its own part of the sea anemone and ''Thor amboinensis'' is found hidden deep among the pseudotentacles.

Life cycle

The female ''Thor amboinensis'' carries the fertilised eggs under her abdomen until they are ready to hatch. The zoea larvae pass through several stages and, before undergoing metamorphosis, are attracted by both chemical cues in the water and visual cues which cause them to settle near potential host anemones. Researchers found that the larvae of ''Thor amboinensis'' were generalists, being attracted by and accepting several different species of anemone as hosts. In some experiments they had a preference for the species of anemone from which the parent shrimp had been collected.

Aquaria

''Thor amboinensis'' is a popular species for marine aquaria. Sexy shrimp are often kept in groups of three or more, due to their small size, a quality that also makes them popular nano reef inhabitants. They will readily host in any anemones present in the aquarium and if an anemone is not available, may host in certain types of coral. Sexy shrimp will scavenge for meaty food scraps, like mysis shrimp, clam, and other prepared fish foods. If a host cnidarian is present, they may feed on the host's mucous.

References

External links

* * {{Taxonbar, from=Q653431 Alpheoidea Crustaceans of the Atlantic Ocean Marine fauna of Africa Marine fauna of Asia Marine fauna of Oceania Marine fauna of Southeast Asia Crustaceans described in 1888 Taxa named by Johannes Govertus de Man Pantropical fauna