These two parasitic mollusks, Thyca crystallina, are growing on the host starfish, Linckia laevigata. This parasitic shell only attaches to this species of starfish, into which it burrows and sucks up nutrients, Philippines

animals in the wild asterias asteroidea atlantis big small biology blue close up color image colourful coral detail dumaguete echinoderm echinodermata echinoderms gastropod green growing halmahera horizontal host indopacific invertebrate laevigata linckia linckia laevigata macro marine life mollusk no people ocean pacific parasite parasitic pattern philippines reef relationship sea life shell small species starfish three animals thyca crystallina tropical tropical climate underwater water zoology animals coralreef coralreefs fauna invertebrates marine no one nobody sealife seastar star fish starfishes sunda tenate wildlife seastars