The significantly higher reproductive output of P. The amount of sperm in the predominantly male gonads however, would not be expected in exclusively self-fertilisers, suggesting that some outcrossing occurs. The low allocation to male function and the simultaneous presence of mature eggs and sperm suggests that both species may be self-fertile.

The amount of sperm in the predominantly female gonads appears sufficient to fertilise all the ova produced. Detection of sperm in these gonads requires histological examination. In the predominantly female gonads, only a few eggs and a small amount of sperm are produced at a time. Both species typically contain 6 to 8 predominantly female gonads and 1 predominantly male gonad. parvivipara in South Australia was examined in specimens collected from one population in 19. vivipara in Tasmania, Midway Point and Tesselated Pavement, was examined in specimens collected in 1991, 19. These species have the most restricted distribution known in the Asteroidea. parvivipara being the smallest known sea star. As characteristic of brooding echinoderms, P.

They are simultaneous hermaphrodites, have intragonadal fertilisation, and incubate their young in the gonads to an advanced juvenile stage. parvivipara have the most derived lifehistory pattern seen in the Asteroidea. The Australian asterinid sea stars Patiriella vivipara and P.

Download the sea of star