Oikopleura (Vexillaria) rufescens, Fol, 1872

Franco, P., Dahms, H. - U., Lo, W. - T. & Hwang, J. - S., 2017, Pelagic tunicates in the China Seas, Journal of Natural History 51 (15 - 16), pp. 917-936 : 927-928

Oikopleura (Vexillaria) rufescens

Morphology

A large appendicularian species. The trunk is compact with a length of 2–7 mm and the tail is long with a strong chord and medium-sized muscular bands. At the right side of the proximal third part of the tail, there are small sub-chordal glands. The endostyle is long and narrow, and at each of its sides it is accompanied by an ovoid buccal gland. The left lobe of the stomach is round. A lower lip is present in juveniles; adults possess a membraneous lip. The ovary and testes are together forming a round structure behind the stomach and oesophagus ( Marine Species Identification Portal 2017).

Biogeography

Typical cold-water appendicularian species from the Arctic , the northern North Atlantic and northern North Pacific Oceans (being most abundant north of 60°N) (WoRMS Editorial Board 2017) .