The fan worms, Notaulax sp., are coral associated fauna belonging to family Sabellidae. Like the other kind of tube worm, they can withdraw into the tubes and “disappeared”. They are immobile once settled on the coral, yet the larvae are pelagic. The crown structure emerges for feeding. Picture was taken in intertidal area of Pari Island, Jakarta (Indonesia).
A parasitic gastropod, Thyca crystallina, found attached on the skin surface of the blue starfish, Linckia laevigata. Some sources said that this parasitism relationship is specific. Having blue coloration, this parasite well-camouflaged on the host. Lacking of the shrimp symbiont could be the factor causing this blue starfish infected by Thyca crystallina.
A macroalgae, Caulerpa sertularioides, is known as the green feather algae due to their feather-structured “leaves”. The green color driven by the chlorophyl that they contain.
Phyllidia varicosa belongs to dorid group of nudibranchs. The retractile rhinophores is among their features. This individual was photographed at Manta Sandy, Raja Ampat (Indonesia) with about 100 mm in body length. They are easy to be recognized by possessing blue ridge and yellow tubercles.
A dorid nudibranch, Phyllidia ocellata, was photographed at Manta Sandy, Raja Ampat (Indonesia) crawling on the sandy substrate. The coloration of this creature varies, but commonly dominated by yellow color with white tubercles spreading on the entire body. This sea slug posses a pair of yellow rhinophores which can be retracted. They are known feeding on sponges.