Ophidiaster granifer, the grained seastar, is a species of starfish in the familyOphidiasteridae. It is found in the Red Sea and the Indo-Pacific and is the only known species of starfish to reproduce by parthenogenesis.
Ophidiaster granifer is a small five armed starfish with a cryptic mottled brown colouration. It has a rough, granular appearance and grows to a diameter of about 10 cm (4 in). The disc is quite small and the medium-length, fairly broad arms have rounded tips.[2][3][4]
Biologyedit
No male Ophidiaster granifer has ever been identified and all known adults are female.[4] As far as is known, Ophidiaster granifer is the only member of the phylumEchinodermata to reproduce exclusively by parthenogenesis. In this species, eggs are liberated into the sea in a synchronous spawning event but no fertilisation takes place. The eggs are large, with a diameter of 0.6 millimetres (0.024 in) and the mother attaches some of them to the underside of boulders. Here they develop until they undergo metamorphosis into juvenile starfish. Other eggs are planktonic and drift with the currents. In either case, the larvae are lecithotrophic and feed off the yolks of their eggs. This reproductive strategy may be linked to the starfish's low fecundity rate and its low population density.[4]
Distribution and habitatedit
Ophidiaster granifer is found on coral reefs in shallow waters in the Red Sea and Indo-Pacific Ocean. It is known from the South China Sea, Japan, Tonga, Fiji, Samoa, northern and western Australia, the Great Barrier Reef, New Guinea, Indonesia, the East Indies and the Philippines. It usually hides under boulders and is found on outer reef flats and patch reefs in lagoons, among broken coral rubble and among the dead bases of tangled coral thickets.[1][4]
Referencesedit
^ abcMah, Christopher (2012). Mah CL (ed.). "Ophidiaster granifer Lütken, 1871". World Asteroidea database. World Register of Marine Species. Retrieved 2013-02-03.
^"Grained Seastar (Ophidiaster granifer)". Marine Fish Picture Gallery. Retrieved 2013-02-03.
^ abcdYamaguchi, M.; Lucas, J. S. (1984). "Natural parthenogenesis, larval and juvenile development, and geographical distribution of the coral reef asteroid Ophidiaster granifer". Marine Biology. 83 (1): 33–44. doi:10.1007/BF00393083.
External linksedit
Photos of Ophidiaster granifer on Sealife Collection
January 01, 1970
ophidiaster, granifer, grained, seastar, species, starfish, family, ophidiasteridae, found, indo, pacific, only, known, species, starfish, reproduce, parthenogenesis, scientific, classification, domain, eukaryota, kingdom, animalia, phylum, echinodermata, clas. Ophidiaster granifer the grained seastar is a species of starfish in the family Ophidiasteridae It is found in the Red Sea and the Indo Pacific and is the only known species of starfish to reproduce by parthenogenesis Ophidiaster granifer Scientific classification Domain Eukaryota Kingdom Animalia Phylum Echinodermata Class Asteroidea Order Valvatida Family Ophidiasteridae Genus Ophidiaster Species O granifer Binomial name Ophidiaster graniferLutken 1871 1 Synonyms 1 Ophidiaster trychnusFisher 1913 Contents 1 Description 2 Biology 3 Distribution and habitat 4 References 5 External linksDescription editOphidiaster granifer is a small five armed starfish with a cryptic mottled brown colouration It has a rough granular appearance and grows to a diameter of about 10 cm 4 in The disc is quite small and the medium length fairly broad arms have rounded tips 2 3 4 Biology editNo male Ophidiaster granifer has ever been identified and all known adults are female 4 As far as is known Ophidiaster granifer is the only member of the phylum Echinodermata to reproduce exclusively by parthenogenesis In this species eggs are liberated into the sea in a synchronous spawning event but no fertilisation takes place The eggs are large with a diameter of 0 6 millimetres 0 024 in and the mother attaches some of them to the underside of boulders Here they develop until they undergo metamorphosis into juvenile starfish Other eggs are planktonic and drift with the currents In either case the larvae are lecithotrophic and feed off the yolks of their eggs This reproductive strategy may be linked to the starfish s low fecundity rate and its low population density 4 Distribution and habitat editOphidiaster granifer is found on coral reefs in shallow waters in the Red Sea and Indo Pacific Ocean It is known from the South China Sea Japan Tonga Fiji Samoa northern and western Australia the Great Barrier Reef New Guinea Indonesia the East Indies and the Philippines It usually hides under boulders and is found on outer reef flats and patch reefs in lagoons among broken coral rubble and among the dead bases of tangled coral thickets 1 4 References edit a b c Mah Christopher 2012 Mah CL ed Ophidiaster granifer Lutken 1871 World Asteroidea database World Register of Marine Species Retrieved 2013 02 03 Grained Seastar Ophidiaster granifer Marine Fish Picture Gallery Retrieved 2013 02 03 Ophidiaster granifer Conchology inc Retrieved 2013 02 03 a b c d Yamaguchi M Lucas J S 1984 Natural parthenogenesis larval and juvenile development and geographical distribution of the coral reef asteroid Ophidiaster granifer Marine Biology 83 1 33 44 doi 10 1007 BF00393083 External links editPhotos of Ophidiaster granifer on Sealife Collection Retrieved from https en wikipedia org w index php title Ophidiaster granifer amp oldid 1110832804, wikipedia, wiki, book, books, library,
