''Aplidium abyssum'' is a

sea squirt Ascidiacea, commonly known as the ascidians or sea squirts, is a paraphyletic class in the subphylum Tunicata of sac-like marine invertebrate filter feeders. Ascidians are characterized by a tough outer test or "tunic" made of the polysaccharid ...

in the family

Polyclinidae Polyclinidae is a family of tunicates in the order Aplousobranchia. Genera The World Register of Marine Species The World Register of Marine Species (WoRMS) is a taxonomic database that aims to provide an authoritative and comprehensive cata ...

and was first described in 1969 by

Patricia Kott Patricia Mather (née Kott) (12 December 1925 – 4 January 2012) was an Australian zoologist and taxonomist known for her research into sea squirts. She became a leader in Australian marine science and achieved international status through her ...

, As with all sea squirts, this species is sessile. It is found in Antarctic waters at depths ranging from 3500 - 6250 metres.cite Q

References

Polyclinidae Taxa named by Patricia Kott Animals described in 1969 {{Tunicata-stub