Odontaster validus is a species of starfish that is classified within the Odontasteridae family. It can be found in the waters around Antarctica with a range that extends across the Southern Ocean, the Antarctic Peninsula, and the South Shetland Islands, among many other areas. It prefers to reside at depths of up to 2,952 feet. This species can reach an average diameter of four inches, with a wide, soft disk. Its arms are thick but come to a sharp point at the tips, which are often raised up above the sand or curled. This species is typically red in color on its upper side and pale pink on its underside.
Odontaster validus is a scavenger that will consume anything it can find including seal feces, bivalve shells, carrion, sea urchins, other species of starfish, sponges, shrimp, and crustaceans. Large groups of this species have been known to gather on beds of unprotected mussels or wounded individuals of the species Acodontaster conspicuous. By studying this behavior, it has been found that the starfish uses chemoreceptors to distinguish between members of its species and other starfish species. One study showed that an individual could also distinguish between starving or satiated individuals by detecting distinct odors. Odontaster validus is thought to be very important for the overall health of its environment due to its tendency to consume benthic larvae and other factors. It is prey to sea anemones and other starfish species.
Odontaster validus breeds between the months of May and September and it is thought that breeding is prompted by changes in light levels, which change drastically in its range from dark to light. Like other species of starfish, this species releases gametes into the water column. Once eggs are fertilized, they change into bipinnaria larvae, but this stage lasts longer than other species at about two months. After about six months, the larvae grow large enough to float to the sea floor and undergo metamorphosis into young starfish. Because of the cold temperatures within this speciesâ€™ range, its metabolic rate is slow, resulting in a maturation period of three to six years and a life span of up to one hundred years.
Image Caption: Red starfish, Odontaster validus. Credit: Zureks/Wikipedia (CC BY-SA 3.0)