''Parazoanthus axinellae'', commonly known as the yellow cluster anemone, is a zoanthid coral found on the southern Atlantic coasts of Europe and in the

Mediterranean Sea The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the ea ...

. Zoanthids differ from true sea anemones, in having a different internal anatomy and in forming true colonies in which the individual animals (polyps) are connected by a common tissue, called the

coenenchyme Coenenchyme is the common tissue that surrounds and links the polyps in octocorals. It consists of mesoglea penetrated by tubes (''solenia'') and canals of the gastrodermis and contains sclerites, microscopic mineralised spicules of silica or of ca ...

Description

The species is yellow or orange in colour and each polyp has twenty-four to thirty-six tentacles disposed in two whorls. The polyps are in diameter and in height. They are connected together in small

colonies In modern parlance, a colony is a territory subject to a form of foreign rule. Though dominated by the foreign colonizers, colonies remain separate from the administration of the original country of the colonizers, the '' metropolitan state'' ...

by a continuous layer of tissue, the coenenchyme. In this species there are sometimes thick yellow spongy masses of tissue at the base of each zooid. A similar zooanthid is '' Parazoanthus anguicomus'', but that species has more numerous tentacles.

Distribution and habitat

''Parazoanthus axinellae'' is found in the temperate eastern Atlantic Ocean and the Mediterranean Sea. It occurs at depths between on rocky substrates.

Ecology

In the Mediterranean Sea, ''Parazoanthus axinellae'' frequently forms dense agglomerations, often in association with the soft coral '' Alcyonium acaule''. Other organisms in these biodiverse habitats include suspension feeders such as sponges, cnidarians,

bryozoa Bryozoa (also known as the Polyzoa, Ectoprocta or commonly as moss animals) are a phylum of simple, aquatic invertebrate animals, nearly all living in sedentary colonies. Typically about long, they have a special feeding structure called a l ...

ns and

tunicate A tunicate is a marine invertebrate animal, a member of the subphylum Tunicata (). It is part of the Chordata, a phylum which includes all animals with dorsal nerve cords and notochords (including vertebrates). The subphylum was at one time ca ...

s, and the rock is encrusted with

coralline alga Coralline algae are red algae in the order Corallinales. They are characterized by a thallus that is hard because of calcareous deposits contained within the cell walls. The colors of these algae are most typically pink, or some other shade of ...

e. The colonies of ''Parazoanthus axinellae'' sometimes divide to form two closely positioned but separate colonies, and colonies growing in close proximity occasionally coalesce.

References

Marine Life

External links

Photos of ''Parazoanthus axinellae'' in th
Sealife Collection
{{DEFAULTSORT:Parazoanthus Axinellae Invertebrates of Europe Animals described in 1862 Parazoanthus Taxa named by Eduard Oscar Schmidt