361 



Distribution: Arctic seas and Central Polar Basin; it mainly lives 

 in the upper 100 m layer. In the western part of the Atlantic Ocean it 

 moves with cold waters south up to Gulf of Maine, while in the eastern 

 part individuals were found in the Bay of Biscay but only at a depth of a 

 few hundred meters. It does not penetrate farther south than the Bering 

 Strait and is not found in the Pacific Ocean. 



The life cycle covers two years; the crustacean dies after reproduc- 

 tion. The period of reproduction is protracted and probably stretches from 

 February to August. 



2. Parathemisto (Parathemisto) japonica Bovallius, 1887 (Fig. 151) 



Bovallius, 1887a: 21; 1889: 258; Behning, 1939: 362; Bowman, 

 1960: 365. 



Length of sexually mature females 9-17 mm; males somewhat 

 smaller. 



This species is quite close to P. abyssorum and differs from it only 

 in a few secondary structural details. The structure of the antennae is 

 the same as in P. abyssorum but in the female antennae II are distinctly 

 longer than antennae I, being about equal to the length of the head and 

 the first three somites of the pereon. In the distal part of the basal plate 



Fig. 151. Parathemisto (Parathemisto) japonica 

 Bovallius, female (P,-ii — after Behning, 1939; rest — Bowman, 1960). 



