•+Patiriella+vivipara

** Scientific Classification ** Kingdom: Animalia   Phylum: Echinodermata   Class: Asteroidea   Order: Spinulosida   Family: Asterinidae   Genus: //Patiriella//   Species: P. //vivipara//

** Physical Description ** -Considered to be the smallest sea star in the biosphere. -Adults are 15-20 mm across, but may reach a maximum size of 30 mm. -Five arms in a round, pentagonal shape -Soft in texture, light orange/yellow in color

-Endemic to Southeast Tasmania -Because the species lack a free-swimming larval stage, there is an inability of the starfish to disperse to new habitats -Lives in rocky areas in the upper intertidal zone, usually under rocks or crevices -Have a water depth limit, being found at depths up to 1.2 m at high water - Prefers sheltered shores, with rocks up to 20 cm high -Has a strong attraction to sandstone -It is unknown whether the species is home range or territorial.
 * Distribution/Habitat **

-Reaches sexual maturity at 12 months of age (at approximately 5 mm in diameter. -Has the ability to breed throughout the year. Its peak reproductive season is from October to January. June is considered to be a mid-year release period, as high numbers of offspring are observed at this time.  -A hermaphroditic species, undergoing self fertilization.  -Its name is derived from the sea star’s capability to produce live young, rather than eggs. This phenomena is known as viviparity. Up to five young are developed in the gonadal sac. When they reach the critical size of 1-2 mm, they rupture from the sac and emerge on the surface of the adult.  -Practice intragonadal cannibalism, in which progeny prey on their intragonadal siblings, once the mouth is opened.  -The species may live for up to 10 years
 * Life Cycle **

-Considered a “vulnerable” species -Threatened by interspecific competition from introduced sea stars (such as the New Zealand sea star), predation by introduced species (such as by the Northern Pacific sea star), and habitat modification and destruction. Human activity cause habitat degradation and modification, especially through the removal of rocks, and pollution.
 * Ecological Threats **

**Sources** [] [|http://www.environment.gov.au/cgi-bin/sprat/public/publicspecies.pl?taxon_id=66767] [|http://zipcodezoo.com/Animals/P/Patiriella_vivipara/] [|http://farm4.static.flickr.com/3083/2322684723_909484dc9f.jpg] [|http://www.dpiw.tas.gov.au/inter.nsf/Images/LBUN-6VS7LS/$File/LiveBearingSeastar_patiriella_vivipara.jpg] [|http://www.environment.gov.au/cgi-bin/sprat/public/displaydistmap.pl?type=species%3Bid=66767] [|http://www.biolbull.org/cgi/content/full/208/2/81]