The Euryalina are a suborder of brittle stars, which includes large species with either branching arms (called "basket stars") or long and curling arms (called "snake stars"). It is sometimes listed as the order Euryalida.

Characteristics

Many of the species in this order have characteristic repeatedly branched arms (a shape known as "basket stars", which includes most Gorgonocephalidae and two species in the family Euryalidae), while the other species have very long and curling arms, and go rather by the name of "snake stars" (mostly abyssal species). Many of them live in deep sea habitats or cold waters, though some basket stars can be seen at night in shallow tropical reefs. Most young basket stars live on a specific type of coral. In the wild, they may live up to 35 years. They weigh up to 5 kilograms (11 lb). Like other echinoderms, basket stars lack blood and achieve gas exchange via their water vascular system.

The basket stars are the largest ophiuroids, with Gorgonocephalus stimpsoni measuring up to 70 cm in arm length with a disk diameter of 14 cm.

Systematics and phylogeny

The fossil record of this group is rather poor and only dates back to the Carboniferous. Basket stars are divided into the following families:

  • family Asteronychidae Ljungman, 1867 -- 4 genera (11 species)
  • family Euryalidae Gray, 1840, emended Okanishi et al., 2011 -- 11 genera (89 species)
  • family Gorgonocephalidae Ljungman, 1867 -- 34 genera (96 species) sub-family Astrocloninae Okanishi & Fujita, 2018 sub-family Astrothamninae Okanishi & Fujita, 2013 sub-family Astrotominae Matsumoto, 1915 sub-family Gorgonocephalinae Döderlein, 1911

Gallery

  • A basket star, located in an area known as "Star Wall", near Maori Bay, New Zealand at a depth of approximately 28 m.
  • Close-up of Astroboa nuda basket star arm
  • A euryalid brittlestar climbing on an octocoral outside Indonesia
  • An abyssal snake star curled around a cold-water coral.
  • The genus Euryale is the only "basket star" not belonging to the Gorgonocephalidae (family Euryalidae).

External links

  • Jo, Yeo Sam (16 October 2014). . The Straits Times.