Clio pyramidata

Taxon-Order: 

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Distribution: 
Worldwide in warm waters of the Atlantic, Indian and Pacific. In the North Pacific it ranges from Washington to Baja California (more common in the southern region).
Habitat: 
Epipelagic to mesopelagic.
Size: 
Up to 9 mm
Diet: 
Phytoplankton, protozoa, juvenile copepods, nauplii, tintinnids, radiolarians, and centrics diatoms have been found in the gut.
Predators: 
The squid Doryteuthis opalescens; also an important food for fish and whales.
Useful Facts or Characters: 

Elongate, pyramid-shaped, and transparent shell.  Has a pronounced central midrib on the dorsal surface.  Shell opening unobstructed; bears a posterior tip. The shell lacks transverse folds and does not curve dorsally.

Natural History: 

Known to be an intermediate host for parasitic copepods that eventually infest fish. Several forms exist within the California Current, but here no attempt was made to distinguish them.