EPICARIDA LIFE-HISTORY OF BOPVA'US 



133 



caridian and Cryptoniscus stages, a further larval state is assumed, 

 called the Bopyrus, which is the functional male, and, after per- 

 forming this function, passes on to the adult female condition. 



The family Bopyridae is parasitic in the l)ranchial chamber 

 of Decapoda, especially Macrura and Anoinura. When one of 

 these Decapods is infested with an adult Bopyrid the gill-chamber 

 in which it is situated is greatly swollen, as shown in Yig. 90. 

 A very common Bopyrid is Bopyrns fougerouxi, parasitic in the 

 gill - chaml»ers <_)f Palaemon scrratns. The Bopyrns larva or 



Fig. 90. — Galathea intermedia, with 

 a Pleurocrypta microbranchiatu 

 under its left brancliiostegite 

 (B), X 1, (Alter Sars.) 



Fig. 91. — Ventral view of male 

 Bopyrus fougerouxi, x 30, 

 .1, 1st and 2nd antennae ; 

 T, 8tli (last) thoracic ap- 

 pendage. (After Bonnier.) 



functional male has the appearance shown in Fig. 01. It 

 differs from the Cryptoniscus stage in possessing a rudimentary 

 pair of anterior thoracic limbs and seven pairs normally 

 developed, while the abdominal limbs are plate - like and 

 branchial in function. The male can often l)e found attached 

 to the female beneath the last pair of incubatory lamellae. 



The adult female condition, which is assumed after the 

 Bopyrid stage is passed through, is illustrated in Fig. 92. 

 The body acquires a remarkable asymmetry, due to the unequal 

 pressure exerted by the walls of the gill - chamber. The 

 antennae and mandibles (Fig. 92, B) are entirely covered up by 

 the largely expanded maxillipedes ; maxillae are, as usual, entirely 



