Brittle Stars

Brittle-stars superficially resemble starfish, they generally have five thin limbs which readily break off when grabbed by a predator however they promptly regenerate. This is where most of the similarities end.

The limbs are clearly set off from a disk shaped body. The vital organs are confined within the body and not extended into the arms as in the case of starfish. The suckerless tube feet are primarily sense organs rather than for movement. Brittle-stars are primarily scavengers.

There are over 10 species found in Cornwall which are difficult to tell apart. The majority are only know by their scientific name. The most abundant is the common brittle star Ophiothrix fragilis. Brittle-stars are found in deeper water in huge numbers but are still common in the inter tidal zone under rocks.

Species of Brittle-stars Found In Cornwall

     Ophiura texturata

  Common Brittle-star Ophiothrix fragilis

      Ophiocomina nigra

Common Brittle-star Ophiothrix fragilis

The central disc is almost pentagonal in shape.

Colour varies in differing shades of brown with tinges of other colours such as red and purple. The limbs are edged by spines.

Ophiura texturata

Ophiura texturata is a burrowing brittle-star living in sand on the lower shore. The central disc is pentagonal. The limbs are thick set for a brittle-star.

The colour varies in shades of brown with sometimes a hint of purple, orange or red. On the central disc at base of each limb are a pair of plates.

Ophiocomina nigra

This brittle star is half again the size of the common brittle-star. The central disc is circular. The colour varies from dark brown to black and has small spines, giving it a velvety appearance.