''Caryophyllia smithii'', the Devonshire cup coral, 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 ...

of solitary coral 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 ...

Caryophylliidae The Caryophylliidae are a family of stony corals found from the tropics to temperate seas, and from shallow to very deep water. Genera *'' Africana'' Ocana & Brito, 2015 *'' Anomocora'' Studer, 1878 *'' Asterosmilia'' Duncan, 1867 *'' Auloc ...

. It is native to the northeastern Atlantic Ocean, the

North Sea The North Sea lies between Great Britain, Norway, Denmark, Germany, the Netherlands and Belgium. An epeiric sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian S ...

and the Mediterranean Sea. There are shallow and deep-water forms which are structurally different. It forms part of a biodiverse community of rock encrusting organisms and is often

parasitised Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has ...

by a

barnacle A barnacle is a type of arthropod constituting the subclass Cirripedia in the subphylum Crustacea, and is hence related to crabs and lobsters. Barnacles are exclusively marine, and tend to live in shallow and tidal waters, typically in eros ...

Description

''Caryophyllia smithii'' is a solitary species of coral with a cup-shaped corallum (stony skeleton) with an elliptical base and a diameter of up to . It is usually broader than it is high. The septa (vertical radial calcareous plates) are arranged in four to five cycles and have smooth edges. The column of the polyp can project by up to from the cup and there are about eighty

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 each with a terminal knob. The polyp is translucent and the colour is variable and may be white, pink, orange, red, brown or bright green. Sometimes there are contrasting regions of colour, especially forming a zig-zag pattern round the mouth. The tentacles are colourless except for the white or brown terminal knobs and the many tiny warts. A form found in deep water is smaller and more delicate; it has an inverse cone shape which is narrowed at the base, while shallow water forms are cylindrical and more robust.

Distribution and habitat

''Caryophyllia smithii'' is found in the northeastern Atlantic Ocean as far north as the

Shetland Islands Shetland, also called the Shetland Islands and formerly Zetland, is a subarctic archipelago in Scotland lying between Orkney, the Faroe Islands and Norway. It is the northernmost region of the United Kingdom. The islands lie about to the no ...

, the North Sea and the Mediterranean Sea. The shallow water form occurs from the

sublittoral zone The neritic zone (or sublittoral zone) is the relatively shallow part of the ocean above the drop-off of the continental shelf, approximately in depth. From the point of view of marine biology it forms a relatively stable and well-illuminated ...

down to about . The deep water form occurs from about down to about , generally in less turbulent waters than the more robust shallow water form. Sometimes its narrow base becomes detached from the substrate and it lives free on the seabed. This coral is abundant around the west coasts of the British Isles below the ''

Laminaria ''Laminaria'' is a genus of brown seaweed in the order Laminariales (kelp), comprising 31 species native to the north Atlantic and northern Pacific Oceans. This economically important genus is characterized by long, leathery laminae and relativ ...

'' zone and may occur at densities of over 100 per square metre below the

red algae Red algae, or Rhodophyta (, ; ), are one of the oldest groups of eukaryotic algae. The Rhodophyta also comprises one of the largest phyla of algae, containing over 7,000 currently recognized species with taxonomic revisions ongoing. The majority ...

zone, being found both on flat rock and in crevices.

Ecology

Caryophyllia smithii Stokes & Broderip, 1828

The habitat of ''Caryophyllia smithii'' is often dominated by

sponge Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through t ...

s and

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 these also grow on the corallum of the coral. The larvae of the

Megatrema anglicum ''Adna'' is a genus of acorn barnacles that grows in association with or semi-parasitically on corals and octocorals. Its only species is ''Adna anglica''. It is found in the intertidal zone on the coasts of northwestern Europe and in the Medite ...

'' often settle near the rim of the corallum where they appear to be immune to the coral's

nematocysts 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 c ...

. They become attached to the stony material and the coral's

epithelium Epithelium or epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. It is a thin, continuous, protective layer of compactly packed cells with a little intercellul ...

overgrows them except for their operculums. A single coral may be colonised by multiple barnacles and these have a tendency to aggregate on one particular part of the coral, often the lower side when corals are growing on vertical surfaces. The presence of these barnacles is semi-parasitic as the coral's tentacles retract when they come into contact with the barnacle's

cirri Giovanni Battista Cirri (1 October 1724 – 11 June 1808) was an Italian cellist and composer in the 18th century. Biography Cirri was born in Forlì in the Emilia-Romagna Region of Italy. He had his first musical training with his brother ...

(feeding appendages), and this hampers its food-gathering activities.

References

{{Taxonbar, from=Q3951686 Caryophylliidae Cnidarians of the Atlantic Ocean Fauna of the Mediterranean Sea Animals described in 1828 Taxa named by William Broderip