Fritillaria pellucida
Kingdom: Animalia
Phylum: Chordata
Class: Appendicularia
Order: Copelata
Family: Fritillariidae
Genus: Fritillaria
Species: F. pellucida
Description
They are Small, solitary, free-swimming tunicates, Characterised by the retention in the adult of a muscular tail and a notochord, a rudimentary or embryonic spinal column typical of all chordates. Their body is divided into two sections, the trunk and the tail. Sexually mature appendicularian resembles the larval chordate form hence also called larvaceans.. Appendicularians are common in most oceans, coastal waters and estuaries, often occurring in large numbers and are well adapted for living in oligotrophic waters (those with low nutrient levels and hence low productivity).
Reference
http://www.marinespecies.org/rams/aphia.php?p=taxdetails&id=103386
http://www.imas.utas.edu.au/zooplankton/image-key/appendicularia
http://www.wildsingapore.com/wildfacts/worm/phoronida/phoronida.htm