''Cerianthus'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

tube-dwelling anemone Tube-dwelling anemones or ceriantharians look very similar to sea anemones but belong to an entirely different class of anthozoans. They are solitary, living buried in soft sediments. Tube anemones live inside and can withdraw into tubes, which ...

s in the

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

Cerianthidae. Members of the genus are found worldwide. They are

predators 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 th ...

scavenger Scavengers are animals that consume dead organisms that have died from causes other than predation or have been killed by other predators. While scavenging generally refers to carnivores feeding on carrion, it is also a herbivorous feeding b ...

s and

omnivore An omnivore () is an animal that has the ability to eat and survive on both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize the nut ...

Characteristics

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 Substrate may refer to: Physical layers *Substrate (biology), the natural environment in which an organism lives, or the surface or medium on which an organism grows or is attached ** Substrate (locomotion), the surface over which an organism lo ...

surrounded by a parchment-like tube which they secrete. This surrounds the whole anemone up to its crown of

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 main ...

s. 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 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.

Species

The following

species In biology, a species is the basic unit of Taxonomy (biology), 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 ...

are currently included in the genus according to the World Register of Marine Species: * ''

Cerianthus bathymetricus ''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. Characteristics Members of this genus do not have a pedal disc with which ...

'' Mosley, 1877 * '' Cerianthus brasiliensis'' Mello-Leitão, 1919 * '' Cerianthus filiformis'' Carlgren, 1893 * '' Cerianthus incertus'' Roule, 1904 * '' Cerianthus japonicus'' Carlgren, 1924 * '' Cerianthus lloydii'' Gosse, 1859 * '' Cerianthus malakhovi'' Molodtsova, 2001 * '' Cerianthus membranaceus'' (Spallanzani, 1784) * '' Cerianthus mortenseni'' Carlgren, 1924 * '' Cerianthus punctatus'' Uchida, 1979 * '' Cerianthus roulei'' Carlgren, 1912 * '' Cerianthus sulcatus'' Kwietniewski, 1898 * '' Cerianthus taedus'' McMurrich, 1910 * '' Cerianthus valdiviae'' Carlgren, 1912 * '' Cerianthus vogti'' Danielssen, 1890

References

Taxa named by Stefano delle Chiaje Cerianthidae Anthozoa genera {{Anthozoa-stub