Dana, 1852
Description
Free edges of carapace spined, the inferio- posterior angle of carapace bears a larger spine [P.avirostris-f/m ]. Six pairs of legs, the most posterior reduced. Antenna [a2] projected forward. Adult copulatory organs longer than the postabdomen.
Female head with prominent rostral point; antennulae [a1] small and truncated.
Male head rounded; antennulae [a1 as long as carapace. Male first leg with a strong distal hook.
Size
Female 0.5-1.2 mm; males 0.7-0.9 mm.
Depth range
Epipelagic.
Ecology
Coastal water species, rare in open oceans. Filter feeder on bacterio- and phytoplankton.
Distribution in the North Sea
Southern North Sea, German Bight, Kattegat.
World distribution
Coastal waters of the tropical and subtropical oceans and warm, temperate regions.
Remark
P. avirostris has been reported from the North Sea as north as 52°N. The species has been found off Helgoland (ca. 54°N) since 1990 regularly.