Coscinasterias tenuispina is a starfish in the family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 Asteriidae

Asteriidae

Asteriidae is a family of Asteroidea in the order Forcipulatida.-Genera:Genera within the family Asteriidae include:* Ampheraster Fisher, 1923 * Anteliaster Fisher, 1923 * Aphanasterias * Asterias Linnaeus, 1758...

. It is sometimes called the blue spiny starfish or the white starfish. It occurs in shallow waters in the Atlantic Ocean and the Mediterranean Sea.

Description

Coscinasterias tenuispina has from 6 to 12 arms (usually 7), often of varying lengths, and grows to 20cm (8in) in diameter. It is a creamy, slightly bluish colour, variously blotched with brown, and is rough textured with short spines.

Distribution

The range of Coscinasterias tenuispina includes the Mediterranean Sea, France, Spain and Portugal, the Azores and other Atlantic Islands, Bermuda, Cuba and the American coast between North Carolina and Santos, Brazil. It is found on the lower shore and down to a depth of about 50m (160ft). A number of divergent populations of the starfish in the Atlantic and Mediterranean are believed to be deserving of being recognized as sub-species. The female population of the starfish in the Mediterranean is larger than that of the males.

Biology

Coscinasterias tenuispina is a predator

Predation

In ecology, predation describes a biological interaction where a predator feeds on its prey . Predators may or may not kill their prey prior to feeding on them, but the act of predation always results in the death of its prey and the eventual absorption of the prey's tissue through consumption...

 and an omnivore

Omnivore

Omnivores are species that eat both plants and animals as their primary food source...

. The starfish is found on hard bottoms and under stones and seaweed

Seaweed

Seaweed is a loose, colloquial term encompassing macroscopic, multicellular, benthic marine algae. The term includes some members of the red, brown and green algae...

 where it mainly feeds on other echinoderm

Echinoderm

Echinoderms are a phylum of marine animals. Echinoderms are found at every ocean depth, from the intertidal zone to the abyssal zone....

s and on bivalve molluscs

Bivalvia

Bivalvia is a taxonomic class of marine and freshwater molluscs. This class includes clams, oysters, mussels, scallops, and many other families of molluscs that have two hinged shells...

. In most of its range, it undergoes sexual reproduction in the winter, while in the summer, it proliferates by asexual reproduction

Asexual reproduction

Asexual reproduction is a mode of reproduction by which offspring arise from a single parent, and inherit the genes of that parent only, it is reproduction which does not involve meiosis, ploidy reduction, or fertilization. A more stringent definition is agamogenesis which is reproduction without...

. To begin the process of asexual reproduction, or "fission", the disc tears itself into two sections, with each part eventually growing extra arms and developing into a new individual. In Brazil, all individuals seem to be male and fission occurs throughout the year.