Salpa fusiformis, Cuvier, 1804

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 : 932

Salpa fusiformis

Morphology

Solitary zooids are elongated, having a slightly convex anterior and a square shape cut off posteriorly. Test entirely smooth. Muscles (M)I–III are strongly fused over a broad area in the mid-dorsal region; M8 and M9 are also strongly fused. Dorsal tubercule is small and C-shaped. Nucleus is relatively small and compact. The aggregate zooids are characterised by a barrel-shaped body and typically fusiform with conical anterior and posterior protuberances of the test. Testes are elongated. Asymmetry of the body is a main characteristic. Test entirely smooth and thin. There are six body muscles; MI–MIV strongly fused over a wide area in the mid-dorsal region; MIV–MV fused laterally; MV– MVI strongly fused in the mid-dorsal region. Solitary zooids measure up to 22–52 mm, while the aggregated zooids are up to 7–52 mm long (excluding projections) (authors’ personal observations; Godeaux et al. 1998).

Biogeography

Cosmopolitan, eurythermal species, occurring from 70°N to 45°S in the Atlantic Ocean, to 45°S in the Indian Ocean and from 50°N to 45°S in the Pacific Ocean. S. fusiformis has got the widest distribution of all salp species, and it is also one of the most abundant species. Distributed from the surface to ca. 800 m depth; seems to perform diurnal vertical migration (WoRMS Editorial Board 2017).