| Actinostella flosculifera | |
|---|---|
 | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Cnidaria |
| Class: | Anthozoa |
| Order: | Actiniaria |
| Family: | Actiniidae |
| Genus: | Actinostella |
| Species: | A. flosculifera |
| Binomial name | |
| Actinostella flosculifera | |
| Synonyms [1] | |
| |
Actinostella flosculifera, the collared sand anemone, [2] is a species of sea anemone in the family Actiniidae. It is found semi-immersed in the sediment in shallow water in the tropical and subtropical Atlantic Ocean.
The only part of this sea anemone that is normally visible is the oral disc, which lies flat on the seabed, the tall cylindrical column being immersed in sediment. The column is cream or pink and the upper part bears sticky warts to which pieces of gravel and fragments of shell adhere. The oral disc is up to 7 cm (3 in) in diameter and bears four whorls of pointed, retractable tentacles close to the funnel-shaped mouth, the outer tentacles being shorter than the inner ones. The outer part of the disc resembles a collar or ruff, and bears irregular fleshy tubercles perforated by fine pores, and separated by slender radial lines. The disc is beige, pinkish, brown or grey, sometimes with some green banding, and blends well with the surrounding sediment in colour and texture. The tentacles are translucent, and sometimes spotted with white. Symbiotic zooxanthellae are present in the tissues, particular in the collar. [2] [3]
Actinostella flosculifera is widely distributed in shallow water in the tropical and sub-tropical Atlantic Ocean. In the Eastern Atlantic its range extends from the Canary Islands and Madeira southwards to São Tomé and Príncipe, and in the western Atlantic its range includes the Bahamas, Bermuda, the West Indies and southwards to the coast of Brazil. The column is buried in sand, gravel or silt. [2] This sea anemone is found at depths down to about 5 m (16 ft), typically in meadows of Thalassia testudinum and Syringodium filiforme , in lagoons and on reef flats with little wave action. [3]
The foot of the column is usually attached to a hard substrate, a rock, a shell or a sea grass rhizome, while the oral disc lies flat on the sediment surface. During the day, the tentacles are contracted and the collar expands so that the zooxanthellae receive the maximum amount of sunlight for photosynthesis; the greenish-brown colour of the collar resembles scraps of dead seagrass and may provide camouflage. At night, the tentacles are extended to catch plankton and organic particles, and the collar contracts. [3] At the slightest disturbance, the whole column contracts and the sea anemone disappears beneath the sediment. It has been found that two types of faecal pellets are emitted through the mouth; one type contains the normal end-products of digestion, but the other contains zooxanthellae debris covered with mucus, which continue to be produced even when the animal is starved of planktonic food. This suggests that the mainstay of the sea anemone's diet may be the digestion of the zooxanthellae found in its tissues. [2]
Anthozoa is a class of marine invertebrates which includes the sea anemones, stony corals and soft corals. Adult anthozoans are almost all attached to the seabed, while their larvae can disperse as part of the plankton. The basic unit of the adult is the polyp; this consists of a cylindrical column topped by a disc with a central mouth surrounded by tentacles. Sea anemones are mostly solitary, but the majority of corals are colonial, being formed by the budding of new polyps from an original, founding individual. Colonies are strengthened by calcium carbonate and other materials and take various massive, plate-like, bushy or leafy forms.
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.
The starburst anemone or sunburst anemone is a species of sea anemone in the family Actiniidae. The sunburst anemone was formerly considered the solitary form of the common aggregating anemone, but was identified as a separate species in 2000.
Urticina crassicornis, commonly known as the mottled anemone, the painted anemone or the Christmas anemone, is a large and common intertidal and subtidal sea anemone. Its habitat includes a large portion of the coastal areas of the northern hemisphere, mainly polar regions, and it lives a solitary life for up to 80 years. Mottled anemones are similar to Dahlia anemones and both are commonly referred to as northern red anemones.
Sea anemones are the marine, predatory animals of the order Actiniaria. They are named after the anemone, a terrestrial flowering plant, because of the colourful appearance of many. Sea anemones are classified in the phylum Cnidaria, class Anthozoa, subclass Hexacorallia. As cnidarians, sea anemones are related to corals, jellyfish, tube-dwelling anemones, and Hydra. Unlike jellyfish, sea anemones do not have a medusa stage in their life cycle.
Anthopleura xanthogrammica, or the giant green anemone, is a species of intertidal sea anemone of the family Actiniidae.
Actinia bermudensis, the red, maroon or stinging anemone, is a species of sea anemone in the family Actiniidae.
Bartholomea annulata is a species of sea anemone in the family 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.
Cynarina lacrymalis is a species of stony coral in the family Lobophylliidae. It is variously known as the flat cup coral, solitary cup coral, button coral, doughnut coral, or cat's eye coral. It is found in the western Indo-Pacific Ocean and is sometimes kept in reef aquaria.
Lebrunia coralligens, commonly known as the hidden anemone, is a species of sea anemone in the family Aliciidae. It is found in shallow water in the Bahamas, the Caribbean, and Brazil. It lives in fissures in corals and rocks.
Condylactis aurantiaca, commonly known as the golden anemone, is a species of sea anemone in the family Actiniidae. This species always remains largely buried in sand or sediment, attached to the substrate, with only the oral disc and tentacles visible.
Aiptasia diaphana, commonly known as the yellow aiptasia or glasrose, is a species of sea anemone native to shallow waters in the temperate eastern Atlantic Ocean and the Mediterranean Sea. It has been introduced into the Red Sea.
Anthopleura ballii, commonly known as the red speckled anemone, is a species of sea anemone in the family Actiniidae. It is found in shallow water in the northeastern Atlantic Ocean.
Anthopleura thallia, commonly known as the glaucous pimplet, is a species of sea anemone in the family Actiniidae. It is found in shallow water in the northeastern Atlantic Ocean and the Mediterranean Sea.
Cerianthus membranaceus, the cylinder anemone or coloured tube anemone, is a species of large, tube-dwelling anemone in the family Cerianthidae. It is native to the Mediterranean Sea and adjoining parts of the northeastern Atlantic Ocean.
Phoronis australis is a species of marine horseshoe worm in the phylum Phoronida. It is found in shallow warm-temperate and tropical waters in the eastern Atlantic Ocean and the Indo-Pacific region and was first detected in the Mediterranean Sea in the late twentieth century. These worms live in association with tube-dwelling anemones, particularly those in the genus Cerianthus.
Haloclava producta is a species of sea anemone in the family Haloclavidae, commonly known as the ghost anemone. This species is native to shallow water in the northwestern Atlantic Ocean, between Cape Hatteras and the Bay of Fundy, where it makes a temporary burrow in soft sediment. It is found on sand flats, both intertidally and subtidally.
Paranthus rapiformis, the onion anemone, is a species of sea anemone in the family Actinostolidae. It was first described by the French naturalist Charles Alexandre Lesueur in 1817 and is native to the northwestern Atlantic Ocean and the Gulf of Mexico.
Mesacmaea mitchellii is a species of sea anemone in the family Haloclavidae. It is found in the northeastern Atlantic Ocean and the Mediterranean Sea where it burrows in soft sediment.
Thyone roscovita is a species of sea cucumber in the family Phyllophoridae. It is found on gravel, sand and mud substrates in the northeastern Atlantic Ocean and the Mediterranean Sea at depths down to about 40 m (130 ft). It is a suspension feeder and catches food particles floating past with its branched feeding tentacles.