Thetys vagina

Taxon-Order: 
Salpida

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Distribution: 
Present in tropical and temperate waters of the Pacific, Atlantic and Indian Ocean.
Habitat: 
Occurs to depths of about 150 m.
Size: 
Aggregate generation: to 250 mm; solitary generation: to 300 mm
Diet: 
Filter feeders; phytoplankton and other small particles.
Predators: 
Medusae, siphonophores, ctenophores, heteropods, sea turtles, marine birds and many fish.
Useful Facts or Characters: 

The aggregate generation zooid possesses a thick, rigid tunic and is covered in small protubrances.  The gut causes a swelling of the tunic at the posterior end.  The aggregate has five body muscle bands.  The solitary generation zooid posesses a very thick, rigid tunic covered in small protubrances and two conspicuous trailing projections that sometimes appear dark green to black.  It has twenty or more body muscle bands.  

Natural History: 

The largest species of salp along the West Coast of the U.S.

References: 

Bone, Q. (1998) The biology of pelagic tunicates. Oxford University Press, Oxford.

Wrobel, D. and Mills, C. (1998) Pacific Coast pelagic invertebrates:  a guide to the common gelatinous animals.  Sea Challengers, Monterey Bay Aquarium, Monterey, CA.

Yount, J.L. (1954) The taxonomy of the Salpidae (Tunicata) of the central Pacific Ocean. Pacific Science 8: 276-330.