FIGURE 1. — Location of sampling sites ( marked with x ) for olive rockfish off Diablo Cove, Calif. 



measured (total length) to the nearest millimeter 

 and examined for parasites on external surfaces, 

 gills, gill cavities, mouth, mesentery, heart, 

 gallbladder, stomach, intestine, and muscle. 

 Copepods and monogenetic and digenetic trem- 

 atodes were fixed in alcohol-formaldehyde-acetic 

 acid (AFA). The trematodes were stained with 

 Harris' hematoxylin, cleared with xylene, and 

 mounted. Nematodes were cleared in lactophenol. 

 Protozoans were studied unpreserved after 

 thawing. 



Most parasites were identified to the lowest pos- 

 sible taxon. However, the microsporida, copepods 

 of the genera Caligus and Lepeophtheirus , and 

 larval cestodes, nematodes, and acanthocephalans 

 were not identified to species. Copepods of the gen- 

 era Caligus and Lepeophtheirus were only identi- 

 fied to genus, as an earthquake destroyed most of 

 the specimens before they were identified to species. 



To facilitate our analysis, we grouped together 

 the relatively uncommon gallbladder myxozoans 

 ( = myxosporidans) (Ceratomyxa sebasta, Lep- 

 totheca informis, L. longipes, L. macrospora, 

 Myxidium incurvatum, Zschokkella ilishae) and 

 the hemiurid trematodes (Lecithaster gibbosus, 

 Parahemiurus merus, Lecithochirium exodicum, 

 and Tubulouesicula lindbergi). 



We analyzed the incidence of infection of all 

 parasites over the entire range of host lengths 

 throughout the year. Differences in prevalence be- 

 tween size classes and between monthly samples 

 were examined using the Kruskal- Wallis test. 



Results 



For our analyses we divided the specimens into 

 11 size classes. Table 1 shows the number of speci- 

 mens taken per month per size class. 



531 



