This is an impressive salp, with solitary body length up to 15 cm.  The test is thick and somewhat gelatinous, with 8 muscle bands.  Like others in the cyclosalp group, Helicosalpa has an elongate gut, rather than the compact type found in Salpa.  It can be distinguished from Cyclosalpa by the presence of a ventral longitudinal muscle.  White patches along the sides of the body form a pair of lines ranging from muscle band 1 to 6.  Although called "light organs" they actually are not bioluminescent.  Solitaries produce long stolons (seen here in the photo) that do not form whorls as in Cyclosalpa.  Aggregate chains are formed by individuals with a firm globular test, length up to 3.5 cm.  Each has a posterior projection that points up and toward the front of the body.  Individuals within chains are asymmetrical and alternate left and right handed forms along the length.  Distinct bands of muscles in the test are not present.  Helicosalpa ranges throughout tropical and subtropical oceanic waters, and occasionally ventures north to at least central California.  

All photographs © David Wrobel and may not be used or copied without permission!