Overview
The Ophiurida are an order of echinoderms within the class Ophiuroidea. It includes the vast majority of living brittle stars.
The upper surface of the disk of Ophiurida is covered with scales[2]. They have bursae for respiration and excretion, dorsal and ventral arm shields are present and usually well developed. Arms are unbranched and incapable of coiling vertically. Most are five-armed, some with 4 or 6 arms as an abnormality, but others properly bear six or seven arms. The madreporite is on the oral surface. The digestive glands are entirely within the central disc[3]. They move their arms side to side by means of ball-and-socket joints. Tropical species tend to contrast color from the environment, but most others prefer to blend in. These biochromes do not include echinoch romes. Some species exhibit luminescence, but only for short periods when stimulated, generally on the bases of the arm spines.
Systematics and phylogeny
There is currently no consensus as to the subdivision of the Ophiurida. The order has been divided into the following suborders and infraorders [4]:
- Ophiomyxina
- Ophiurina
- Hemieuryalina
- Chilophiurina
- Gnathophiurina
- Ophiodermatina
- Ophiolepidina
Another classification scheme divides it into the following suborders[5]:
- Chilophiurina Matsumoto, 1915
- Laemophiurina Matsumoto, 1915
- Ophiothricidae Ljungman, 1867 (= Ophiotrichidae)
- Ophiurina M?ller & Troschel, 1840
Another classification scheme divides it as[6]:
- Chilophiurina
- Laemophiurina
- Gnathophiurina
Ecology
Ophiurida have a world-wide distribution range and are found in oceans in different depths. Most of them are herbivores or detritus feeders.
ics and phylogenyThere is currently no consensus as to the subdivision of the Ophiurida. The order has been divided into the following suborders and infraorders [4]:
- Ophiomyxina
- Ophiurina
- Hemieuryalina
- Chilophiurina
- Gnathophiurina
- Ophiodermatina
- Ophiolepidina
Another classification scheme divides it into the following suborders[5]:
- Chilophiurina
Matsumoto, 1915 - Laemophiurina Matsumoto, 1915
- Ophiothricidae Ljungman, 1867 (= Ophiotrichidae)
- Ophiurina M?ller & Troschel, 1840
Another classification scheme divides it as[6]:
- Chilophiurina
- Laemophiurina
- Gnathophiurina
Ecology
Ophiurida have a world-wide distribution range and are found in oceans in different depths. Most of them are herbivores or detritus feeders.
References
- ^ E.Clarkson, E.N.K. Clarkson, Invertebrate Palaeontology and Evolution. Wiley-Blackwell; 4.ed. (1998)
- ^ Grzimek's Animal Life Encyclopedia, vol 1, Gale Cengage 2003
- ^ R.C.Brusca, G.J.Brusca. Invertebrates. Sinauer Associates, 2 ed.(2003)
- ^ Smith, A.B.; Paterson, G.L.J. . Ophiuroid phylogeny and higher taxonomy: morphological, molecular and palaeontological perspectives. Zool. J. Linn. Soc. 114 (1995)
- ^ European Register of Marine Species
- ^ Mikko's Phylogeny Archive
Taxonomy
The Order Ophiurida is further organized into finer groupings including:
- Suborder (1): Gnathophiurina
- Family (7): Amphilepididae · Amphiuridae · Ophiactidae · Ophiochitonidae · Ophiolepididae · Ophiothricidae · Ophiotrichidae
- Species: ZipcodeZoo has pages for 1,423 species and subspecies in the Order Ophiurida.
Families
Amphilepididae
Amphilepididae are a small family of brittle stars of the suborder Gnathophiurina. It contains one genus (Amphilepis) and the following species: [more]
Amphiuridae
Amphiuridae (commonly called long-armed burrowing brittle stars or burrowing brittle stars) are a large family of brittle stars of the suborder Gnathophiurina. Some species are used to study echinoderm development (e.g. and Amphioplus abditus) and bioluminescence (the dwarf brittle star, Amphipholis squamata). [more]
Ophiactidae
Ophiactidae are a family of brittle stars. It includes the following genera: [more]
Ophiochitonidae
Ophiolepididae
Ophiothricidae
Ophiothricidae are a family of ophiurid brittle stars within the infraorder Gnathophiurina. [more]
Ophiotrichidae
At least 129 species and subspecies belong to the Family Ophiotrichidae.
More info about the Family Ophiotrichidae may be found here.
References
- ^ E.Clarkson, E.N.K. Clarkson, Invertebrate Palaeontology and Evolution. Wiley-Blackwell; 4.ed. (1998)
- ^ Grzimek's Animal Life Encyclopedia, vol 1, Gale Cengage 2003
- ^ R.C.Brusca, G.J.Brusca. Invertebrates. Sinauer Associates, 2 ed.(2003)
- ^ Smith, A.B.; Paterson, G.L.J. . Ophiuroid phylogeny and higher taxonomy: morphological, molecular and palaeontological perspectives. Zool. J. Linn. Soc. 114 (1995)
- ^ European Register of Marine Species
- ^ Mikko's Phylogeny Archive
Sources
- The text on this page is licensed under the GNU Free Documentation License. It includes material from Wikipedia retrieved Wednesday, April 25, 2012.
- Photographs on this page are copyrighted by individual photographers, and individual copyrights apply.
- The technology underlying this page, including the controls behind Keep Exploring, is owned by the BayScience Foundation. All rights are reserved.