Acodontaster conspicuus is a species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 of 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...

 Odontasteridae

Odontasteridae

Odontasteridae is a family of sea stars. Members of the family are known as cushion stars and have relatively broad discs and five short tapering arms.-Genera:The following genera are listed in the World Register of Marine Species:...

. It is found in the Southern Ocean

Southern Ocean

The Southern Ocean comprises the southernmost waters of the World Ocean, generally taken to be south of 60°S latitude and encircling Antarctica. It is usually regarded as the fourth-largest of the five principal oceanic divisions...

, in the waters off Antarctica and the island groups nearby.

Description

Acodontaster conspicuus grows to about 30 cm (12 in) in diameter. It has 5 arms and the body has a cushion-like appearance, being thick except around the margins where there is a thin flat area. The upper surface has radially arranged granulations. The colour varies but is usually orange or brown.

Distribution

Acodontaster conspicuus is found in the cold seas around Antarctica, including the Antarctic Peninsula

Antarctic Peninsula

The Antarctic Peninsula is the northernmost part of the mainland of Antarctica. It extends from a line between Cape Adams and a point on the mainland south of Eklund Islands....

 and South Georgia, at depths down to 750 metres.

Ecology

Acodontaster conspicuus feeds on sponges including the fast growing species, Mycale acerata, which might dominate the Antarctic marine ecosystem

Ecosystem

An ecosystem is a biological environment consisting of all the organisms living in a particular area, as well as all the nonliving , physical components of the environment with which the organisms interact, such as air, soil, water and sunlight....

 if not kept under control. Acodontaster conspicuus is itself eaten by the proboscis worm

Nemertea

Nemertea is a phylum of invertebrate animals also known as "ribbon worms" or "proboscis worms". Alternative names for the phylum have included Nemertini, Nemertinea and Rhynchocoela. Although most are less than long, one specimen has been estimated at , which would make it the longest animal ever...

, Parborlasia corrugatus

Parborlasia corrugatus

Parborlasia corrugatus is a proboscis worm in the family Cerebratulidae. This species of proboscis or ribbon worm can grow to in length, and lives primarily in marine environments down to . It is a widely distributed scavenger and predator.-Description:...

, and by the much smaller starfish, Odontaster validus

Odontaster validus

Odontaster validus is a species of starfish in the family Odontasteridae. Its range includes the Southern Ocean and the seas around the mainland and islands of Antarctica.-Description:...

, which hunt in packs.