322 



6. Distal process of 5th segment of pereopods II does not extend to half 

 length of 6th segment. Inner lobes of maxillipeds apically bear one 



spine. Sixth segment of pereopods V-VII not armed 



6. H. leptura Bowm. 



— Distal process of 5th segment of pereopods II extends more than half 

 length of 6th segment. Inner lobes of maxillipeds bear two spines 

 apically. Sixth segment of pereopods V-VII bears submarginal row 



of long setae, especially well developed in pereopods VII 



7. H. bowmani Vinogr. 



263 All species of Hyperia as well as those of some other genera of 



the family Hyperiidae live on jellyfish or ctenophorans as ectoparasites 

 and commensales. They feed on the residual food of the jellyfish (Hol- 

 lowday, 1948; and others) and eat away their tissues: tentacles, oral 

 part, manubrium (Browman et al, 1963; white and Bone, 1972; Sheader, 

 1974), and gonads (Romanes, 1877; Metz, 1967). Young H. galba and 

 H. macrocephala were found which had penetrated into the mesogloea 

 right up to the gastrovascular system of the jellyfish (Metz, 1967). 



Direct observations on the male H. galba revealed that the crus- 

 taceans attach themselves on the dorsal surface of the bell of the jel- 

 lyfish, close to its edge after turning back on it, and remain attached 

 by pereopods V-VII (Fig. 128). The crustaceans pass most of their time 

 in such a position (Bowman et al, 1963) and thus can grab the catch- 

 ing filaments or oral tentacle of the jellyfish with their free pereopods 

 and eat them. Probably, such a nature of feeding is associated with the 



262 Fig. 128. Characteristic pose of male Hyperia galba on the bell of a jellyfish 



(after Bowman and Gruner, 1973). 



