Oikopleura dioica, 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

Oikopleura dioica

Morphology

This appendicularian is rather small with an ovoid trunk and narrow tail. It measures- 2–4 mm where the length of the tail is about 4 times the body length. It has a narrow tail muscle and two distinct subchordal cells at about 1/2 to 2/3 of the way down the tail length. The endostyle is large, and prolongated near the anus. Sexes are separate, with posterior ovary and testis. The mouth and its lower lip and the buccal glands are small and spherical. Behind the entrance of the intestine the right stomach lobe forms a cloacal sac ( Godeaux et al. 1998; authors’ personal observations).

Biogeography

A semi-cosmopolitan, neritic species from warm and temperate waters. It is present in the Atlantic, Indian and Pacific Oceans, the Mediterranean Sea, and the Red Sea. Of all Appendicularia, O. dioica is the most eurythermal and euryhaline species (WoRMS Editorial Board 2017).