A 



^ 



^ 



n** 



4 



■'■f 



^•^%lfc^ ^. 



\ 



•'4:^ 



-'■ r' 



Figure 2. — Dungeness crab egg samples showing (A) no epibio- 

 tic folding on the egg membrane (78x), (B) moderate epibiotic 

 fouling on the egg membrane (96x ), and (C) very heavy epibiotic 

 fouling on the egg membrane (57 x). 



The epibiotic fouling organisms found were 

 similar to those noted on other crustaceans by 

 Nilson et al. ( 1975). Particularly prominent were 

 the long filamentous cyanophytes which resem- 

 bled Oscillatoria and bacterial filaments similar to 

 Leucothrix. In heavily fouled samples stalked pro- 

 tozoans (vorticellids) were also observed. These 

 and the filamentous organisms trapped detrital 

 material, which added to the overall contamina- 

 tion of the eggs. Fouling on the egg stalk was often 

 more extensive than fouling on the egg membrane 

 proper. Empty egg cases also showed heavier foul- 

 ing than those containing embryos. In many cases 

 where fouling was observed, worms were found, 

 and the population of worms was generally larger 

 on egg samples with heavier fouling. The worms 

 were identified as the nemertean egg predator 

 Carcinonemertes epialti as described by Kuris 

 (1973). 



203 



