Shields and Kuris: Carononemerces wickhami n sp from a spiny lobster 



285 



bases, and stylet apparatus. These species prey on large 

 host eggs. In addition, the morphology of the stylet of 

 C. wickhami is similar to that of C. regicides (i.e., in 

 the form of a broad, flat dagger). The above adapta- 

 tions may allow penetration of the thick outer coat of 

 these large eggs (Wickham and Kuris 1988). 



The presence of ovarian pores may be of taxonomic 

 value to the genus. Distinct ovarian pores were not 

 observed on female C. wickhami. Similarly, Strieker 

 (1986) did not find distinct ovarian pores on C. epialti. 

 Takakura (1910) and Shields et al. (1989) reported 

 distinct ovarian pores from C. mitsukurii and C. 

 regicides, respectively. The ovarian pores of C. regi- 

 cides are typically found prior to ovulation, but are not 

 apparent prior to oviposition (Shields et al. 1989); C. 

 mitsukurii appears to follow a similar pattern (Shields, 

 pers. observ.). 



The larvae of C. wickhami resemble the typical hoplo- 

 nemertean larval form (Gibson 1972, p. 150), and are 

 similar to the larvae of C. epialti in gross morphology 

 (Strieker and Reed 1981). Larvae most likely undergo 

 direct development into the juvenile stage upon settling 

 onto their host (Strieker and Reed 1981). The larva of 

 C. wickhami is similar to that of C. carcinophila, C. 

 epialti, and C. regicides; the larvae do, however, differ 

 in size. Carcinoyiemertes ivickharni has the smallest 

 larva yet described for the genus. 



Mature C. wickhami were found only in the broods 

 of ovigerous lobsters. Further, these nemerteans have 

 been collected only from lobsters with eggs in relatively 

 advanced stages of development (development of eye 

 placodes initiated— 8 of 19 lobsters examined). No 

 nemerteans were recovered from 6 lobsters with rela- 

 tively early broods nor from 3 lobsters held for dissec- 

 tion after eclosion. Carcinonemertes wickhami does not 

 appear to migrate to the branchial chamber and into 

 the branchiae after host eclosion, nor does it move to 

 the limb apodemes and axillae (see below). 



Three distinct life-history patterns have emerged for 

 sb{ of the eight species of Carcinonemertes. These pat- 

 terns appear related to the developmental timing of 

 host embryogenesis (oviposition to eclosion): embryo- 

 genesis in various reptantian decapods can be of short 

 (e.g., 13-16 days), moderate (e.g., 40-120 days), or long 

 duration (e.g., 120-300-1- days). In addition, life-history 

 patterns may be useful taxonomic characters as few 

 differences in morphology aid in distinguishing be- 

 tween species. 



1 Portunid crabs have a short duration of embryo- 

 genesis (Churchill 1919, Sandoz and Rogers 1944). 

 Careinonemertid larvae settle primarily on ovigerous 

 female crabs where they quickly metamorphose and 

 mature. After eclosion, adult worms migrate to the 



