WING: ELLOBIOPSIDAE FROM NORTH PACIFIC 



100 specimens in literature published on Atlantic 

 Pasiphaea spp. 



This parasite apparently has both physiological 

 and morphological effects on the host shrimp. As 

 noted by Bergan (1953), male and female shrimp 

 were both parasitized; none of the parasitized 

 females were carrying eggs, which indicates that 

 the parasite must have sterilized the host. Al- 

 though Bergan (1953) found no evidence that the 

 root system of the parasite penetrates the host's 

 gonads, it is possible that the parasite controls 

 the sexual development and molting processes 

 of the host either by influencing hormone produc- 

 tion (Hoffman and Yancey 1966) or by a starva- 

 tion effect (Wickstead 1963). In addition to the 

 effect on growth and reproduction, T. capillosus 

 causes a characteristic upward deflection of the 

 host's rostrum (Boschma 1959; McCauley 1962; 

 Hoffman and Yancey 1966). It is not known 

 whether the deformation of the rostrum occurs 

 before or after the primary stalks break through 

 the cuticle of the host. The ellobiopsid is fre- 

 quently lost or degenerates, but the upturned 

 rostrum remains as evidence of parasitism. It 

 was primarily on the basis of the upturned ros- 

 trum that Pasiphaea principalis Sund was er- 

 roneously distinguished from P. tarda Kr0yer 

 (Boschma 1959). 



Thalassomyces calif or niensis 

 CoUard 1966 



Thalassomyces californiensis n.sp. — Collard 



(1966). 

 Thalassomyces californiensis — Vader (1973a, b). 



Thalassomyces californiensis is a parasite of the 

 shrimp Pasiphaea emarginata Rathbun off the 

 coast of central California (Collard 1966). Thalas- 

 somyces californiensis superficially resembles 

 T. capillosus, but the primary stalks penetrate 

 the eye stalks of the host rather than the base 

 of the rostrum. Five to 20 primary stalks may 

 be associated with each organ of fixation (Collard 

 1966) rather than the one to four primary stalks 

 found in T. capillosus. Collard did not find any 

 major morphological or histological changes 

 caused by this parasite. 



Thalassomyces species (not identified) 



Thalassomyces sp. — Collard (1966). 



A third species of Thalassomyces infects Pasi- 

 phaea chacei Yaldwyn in southern Baja California 

 but is unidentified. This parasite is found on the 

 anterior part of the abdomen (R. Lavenberg, 

 Los Angeles County Museum of Natural History, 

 Los Angeles, CA 90007, pers. commun.). 



Ellobiopsis chattoni CauUery 1910 



Ellobiopsis chattoni — Hoffman and Yancey 

 (1966). 



Hoffman and Yancey (1966) reported E. chat- 

 toni as a parasite of the calanoid copepod Metridia 

 longa (Lubbock) in Auke Bay, southeastern 

 Alaska. During monthly sampling of the Auke 

 Bay vicinity by the NMFS from August 1962 

 to January 1964, copepods parasitized by E. 

 chattoni were found from late July through 

 December; 5 to 25% of the M. longa were parasi- 

 tized and peak infestation was in late October 

 and early November. Hoffman and Yancey (1966) 

 found only M. longa infected by E. chattoni 

 despite the availability of other potential calanoid 

 hosts — Calanus finmarchicus (Gunnerus), 

 Pseudocalanus minutus (Kr0yer), and Acartia 

 clausii Giesbrecht. Wickstead (1963) noted a 

 similar 100% host specificity of E. chattoni on 

 Undinula vulgaris var. major Sewell in the 

 Zanzibar Channel. 



There may be a large seasonal and yearly 

 variation in the rate of infection by ellobiopsids 

 and perhaps even in the species of copepod in- 

 fected. I sampled zooplankton monthly in Auke 

 Bay and near Point Retreat (Figure 5) from Sep- 

 tember 1969 through October 1970. During this 

 time, E. chattoni did not infect M. longa but did 

 infect P. minutus; the level of infection was very 

 low, however: one to six P. minutus were taken 

 each month from the thousands of potential hosts 

 examined, but no distinct seasonal trend of 

 infection was evident. 



Ellobiocystis caridarum 

 (Coutiere 1911) 



Sampling with the 1 .8-m Isaacs-Kidd mid-water 

 trawl in southeastern Alaska yielded many 

 Pasiphaea pacifica (a pelagic shrimp) with the 

 epibiont E. caridarum on their mouth parts. 

 Boschma (1959) discussed the difficulties in 

 identifying the various species of Ellobiocystis 



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