The biology of Pandalus borealis, P. hypsinotus, and Pandalopsis japonica (Crustacea, Decapoda, Pandalidae) in the Far East Seas

摘要

Some 11500 specimens of Pandalus borealis Kr., P. hypsinotus Brandt, and Pandalopsis japonical Balss were collected by trawl, traps and dip-net from the Tatar Strait. Pandalus hypsinotus young of the current year (Carapace length is 10 mm) at the age of 5-7 years were found at depths of 40-50 m. A considerable number of shrimp from this group was found during gale and after it among Zostera marina at a depth of 0.2-0.5 m. The vertical distribution of the P. hypsinotus is in the layer of up to 0.2-460 m. The shrimp of this species become mature as males at the age of 2.5 years, the change their sex at the age of 3-4 years and become females at the age of 5-6 years. They live for 2-3 years more. In the Pandalus borealis population from western Kamchatka, primary females are present. The carapace length of these shrimps reaches 34.5 mm. In the Tatar Strait, shrimp live for about 8 years and reach the carapace length of 39.6 mm. The carapace length in intersex varies from 21.5 to 34 mm. A primary female of Pandalopsis (the carapace length is 20.8 mm) with external eggs was found in the Tatar Strait. Shrimp of this species function as male for 3-4 years, then they change sex and live as females 2-3 years more.