| Cerianthus | |
|---|---|
 | |
| Cerianthus membranaceus | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Cnidaria |
| Class: | Anthozoa |
| Subclass: | Ceriantharia |
| Order: | Spirularia |
| Family: | Cerianthidae |
| Genus: | Cerianthus Delle Chiaje, 1830 [1] |
| Species | |
| Synonyms | |
| |
Cerianthus is a genus of tube-dwelling anemones in the family Cerianthidae. Members of the genus are found worldwide. They are predators, scavengers and omnivores. [2]
Members of this genus do not have a pedal disc with which to hold themselves in position. Instead they live semi-buried in soft substrate surrounded by a parchment-like tube which they secrete. This surrounds the whole anemone up to its crown of tentacles. Sand grains, debris and shell fragments usually stick to the outer side of the tube. When it is disturbed, the anemone retracts swiftly back into the tube. Some of the larger species can have a column of up to 25 inches (640 mm) in length. The longitudinal muscles in the trunk are powerful but the transverse ones are weak. The outer ring of tentacles are long and tapering. The tube is flexible and the anemone can extend its tentacles a surprisingly long way. The inner ring of tentacles surrounds the central mouth and assists in pushing food inside. [2]
The following species are currently included in the genus according to the World Register of Marine Species: [1]
Tube-dwelling anemones or ceriantharians look very similar to sea anemones but belong to an entirely different subclass of anthozoans. They are solitary, living buried in soft sediments. Tube anemones live inside and can withdraw into tubes, which are composed of a fibrous material made from secreted mucus and threads of nematocyst-like organelles known as ptychocysts. Within the tubes of these ceriantharians, more than one polyp is present, which is an exceptional trait because species that create tube systems usually contain only one polyp per tube. Ceriantharians were formerly classified in the taxon Ceriantipatharia along with the black corals but have since been moved to their own subclass, Ceriantharia.
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.
Epiactis is a genus of sea anemones in the family Actiniidae. There are about nineteen recognised species and the type species is Epiactis prolifera.
Peachia is a genus of sea anemone in the family Haloclavidae. Members of this genus typically burrow into soft substrates. The only part of the animal that is normally visible is the oral disc and tentacles which lie flat on the sand in a star shape. The type species is Peachia cylindrica.
Triactis is a genus of sea anemone in the family Aliciidae. It is monotypic, having only one species – Triactis producta. This is found in shallow waters in the Indo-Pacific where it lives on the seabed, rocks and corals. It derives much of its energy needs from the symbiotic algae it contains. It also forms a mutualistic relationship with small Lybia crabs.
Cerianthus lloydii is a species of tube-dwelling sea anemone in the family Cerianthidae. It is sometimes called the lesser cylinder anemone and is found in shallow seas around the coasts of north west Europe.
The burrowing anemone is a species of tube-dwelling anemone in the family Cerianthidae.
Pachycerianthus multiplicatus, commonly known as the firework anemone, is a species of tube anemone in the family Cerianthidae. This species is found in sheltered, subtidal mud at depths of 10 - 130m.
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.
Cerianthidae is a family of tube-dwelling anemones in the order Spirularia of the subclass Ceriantharia.
Ceriantheomorphe is a genus of tube-dwelling anemones in the family Cerianthidae.
Ceriantheomorphe brasiliensis is a species of tube-dwelling anemones in the family Cerianthidae. It is found in the tropical western Atlantic Ocean, the Caribbean Sea and the Gulf of Mexico. It is currently listed as endangered based on a lack of evidence.
Ceriantheopsis americana is a species of tube-dwelling anemone in the family Cerianthidae. It is a burrowing species and lives in deep sand or muddy sand in a long slender tube that it creates.
Arachnactidae is a family of tube-dwelling anemones in the order Ceriantharia. It is the only family in the monotypic order Penicillaria and comprises around 38 species. They differ from other ceriantharians in the makeup of their cnidome, the relative sizes of the oral discs and the shape and structure of the mesenteries. These tube anemones dwell in parchment-like tubes immersed in soft sediment, and have two whorls of tentacles, the outer ones being much longer than the inner ones.
Arachnanthus is a genus of tube-dwelling anemones in the family Arachnactidae. Members of the genus are found worldwide.
Arachnanthus sarsi is a species of tube-dwelling anemone in the family Arachnactidae. This species is found in the North Atlantic in subtidal sand or muddy sand at depths of 15–130 m.
Epiactis thompsoni, the red-striped anemone, is a species of marine invertebrate in the family Actiniidae, found in New Zealand and South Australia. They are commonly found in the rocky intertidal zone.
Paranthus is a genus of sea anemones in the family Actinostolidae.
Pachycerianthus is a genus of marine tube-dwelling anemones in the family Cerianthidae.
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