''Bartholomea annulata'' 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 ...

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

in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Aiptasiidae, commonly known as the ringed anemone or corkscrew anemone. It is one of the most common anemones found on reefs in the Caribbean Sea.

Description

The ringed anemone can reach a diameter of when fully extended. The column is short and wide and the oral disc with its central mouth can be across. There are about two hundred long, translucent tentacles ringed with whorls and spirals formed by groups of

cnidocyte A cnidocyte (also known as a cnidoblast or nematocyte) is an explosive cell containing one large secretory organelle called a cnidocyst (also known as a cnida () or nematocyst) that can deliver a sting to other organisms. The presence of this ce ...

s. The general colour is grey or brown with the cnidocyte area cream coloured. The anemone contains

symbiotic 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 ...

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 ''Sy ...

, single-celled algae that live within its tissues. During the day these use energy from the sun to manufacture carbohydrates by photosynthesis. The sea anemone benefits from this and the algae have a safe lodging free from the likelihood of

predation Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the ...

Distribution and habitat

The ringed anemone is a common species in the Caribbean and Gulf of Mexico. Its range extends from Bermuda, Florida and Texas to the northern coast of South America. It is found on reefs and on soft substrates such as coral rubble or sand at depths down to about . It usually occupies a hole or crevice or lives under a rock, drawing back out of sight if disturbed. It has been found using the empty shell of the queen conch ''

Lobatus gigas ''Aliger gigas,'' originally known as ''Strombus gigas'' or more recently as ''Lobatus gigas'', common name, commonly known as the queen conch, is a species of large sea snail, a marine gastropod mollusc in the family (biology), family of true c ...

'' as a home.

Biology

Some of the ringed anemone's nutritional needs are supplied by the zooxanthellae. It also feeds by extending its tentacles to catch

zooplankton Zooplankton are the animal component of the planktonic community ("zoo" comes from the Greek word for ''animal''). Plankton are aquatic organisms that are unable to swim effectively against currents, and consequently drift or are carried along by ...

and small invertebrates. These are immobilised by the cnidocytes and transferred by the tentacles to the mouth. Reproduction may be by pedal laceration. In this process, part of the basal disc of the sea anemone gets detached as the anemone moves over the substrate, and this piece is able to grow into a new individual. The anemone can also reproduce by liberating

gamete A gamete (; , ultimately ) is a haploid cell that fuses with another haploid cell during fertilization in organisms that reproduce sexually. Gametes are an organism's reproductive cells, also referred to as sex cells. In species that produce t ...

s into the

water column A water column is a conceptual column of water from the surface of a sea, river or lake to the bottom sediment.Munson, B.H., Axler, R., Hagley C., Host G., Merrick G., Richards C. (2004).Glossary. ''Water on the Web''. University of Minnesota-D ...

. After fertilisation, the

eggs Humans and human ancestors have scavenged and eaten animal eggs for millions of years. Humans in Southeast Asia had domesticated chickens and harvested their eggs for food by 1,500 BCE. The most widely consumed eggs are those of fowl, especial ...

hatch into larvae which are

plankton Plankton are the diverse collection of organisms found in Hydrosphere, water (or atmosphere, air) that are unable to propel themselves against a Ocean current, current (or wind). The individual organisms constituting plankton are called plankt ...

ic and drift with the current. After further development they settle on the seabed and undergo

metamorphosis Metamorphosis is a biological process by which an animal physically develops including birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation. Some inse ...

into juvenile anemones.

Ecology

Predators on the ringed anemone include

starfish Starfish or sea stars are star-shaped echinoderms belonging to the class Asteroidea (). Common usage frequently finds these names being also applied to ophiuroids, which are correctly referred to as brittle stars or basket stars. Starfish ...

nudibranch Nudibranchs () are a group of soft-bodied marine gastropod molluscs which shed their shells after their larval stage. They are noted for their often extraordinary colours and striking forms, and they have been given colourful nicknames to matc ...

s and

sea spider Sea spiders are marine arthropods of the order Pantopoda ( ‘all feet’), belonging to the class Pycnogonida, hence they are also called pycnogonids (; named after ''Pycnogonum'', the type genus; with the suffix '). They are cosmopolitan, fou ...

s such as ''( Pigrogromitus timsanus)''. Infestation with this sea spider caused the sea anemone to retract its tentacles and produce copious amounts of mucus and to be unable to attach to the substrate, with death often following. The sea spider seemed unaffected by the stinging cnidocytes of the anemone. The ringed anemone is associated with a number of other invertebrates including the

opossum shrimp Mysida is an order of small, shrimp-like crustaceans in the malacostracan superorder Peracarida. Their common name opossum shrimps stems from the presence of a brood pouch or "marsupium" in females. The fact that the larvae are reared in ...

'' Heteromysis actiniae'' and several species of

cleaner shrimp Cleaner shrimp is a common name for a number of swimming decapod crustaceans, that clean other organisms of parasites. They belong to any of three families, Hippolytidae (including the Pacific cleaner shrimp, ''Lysmata amboinensis''), Palaem ...

s. These include '' Ancylomenes pedersoni'' and the spotted cleaner shrimp (''Periclimenes yucatanicus'') which live close to it or among its tentacles. They invite fish to approach by lashing their white antennae, relying on the anemone to keep them safe from attack. They then nibble at any external

parasites Parasitism is a Symbiosis, close relationship between species, where one organism, the parasite, lives on or inside another organism, the Host (biology), host, causing it some harm, and is Adaptation, adapted structurally to this way of lif ...

that may be attached to the fish.

References

External links

* {{Taxonbar, from=Q4865216 Aiptasiidae Animals described in 1817 Taxa named by Charles Alexandre Lesueur Cnidarians of the Caribbean Sea