FISHERY BULLETIN: VOL. 84, NO. 3 



tion (Manier et al. 1971). The infected amphipods 

 these authors examined were apparently unaffected 

 by the parasite. However, before one could deter- 

 mine the mortality rate due to syndinid infection, 

 it would be necessary to examine moribund and dead 

 amphipods found in the field for presence of syn- 

 dinids, as well as to follow progress of infection in 

 the laboratory. Syndinids appear to be unaffected 

 by host defense mechanisms. Spores of syndinids 

 that parasitize the hemocoel must exit through 

 breaks in the exoskeleton or gut. Because hemocytes 

 are in short supply by time of sporulation and other 

 host resources can be expected to be depleted, host 

 defense mechanisms probably would not be suffi- 

 cient to prevent death by infection with other micro- 

 organisms that would enter through the breaks or 

 death by leakage of body fluids. Assuming, on the 

 basis of evidence presented in this paper, that 

 amphipods are unable to contain syndinid infections 

 and that most infections would therefore progress 

 to the spore stage, syndinid infection could serve 

 as a population regulator in heavily parasitized 

 species. Monoculodes edwardsi and Ampelisca 

 vadorum, which had overall prevalences of syndinid 

 infection of 23% and 17% respectively, are examples 

 of species that might be affected in this manner. 



ACKNOWLEDGMENTS 



Sara V. Otto, Maryland Department of Natural 

 Resources, Oxford, MD, aided in translation of ar- 

 ticles from the French, and the following person- 

 nel from the Oxford and Sandy Hook Laboratories 

 of the Northeast Fisheries Center helped as follows: 

 Frank Steimle, David Radosh, Linda Dorigatti, 

 Gretchen Roe, and Sharon MacLean collected the 

 amphipods; Ann Frame and Linda Dorigatti aided 

 in their identification; and Gretchen Roe, Dorothy 

 Howard, Cecelia Smith, and Linda Dorigatti 

 prepared the specimens for histological examination. 

 My thanks to all of the above. 



LITERATURE CITED 



Alfert, M., and I. I. Geschwind. 



1953. A selective staining method for the basic proteins of 

 cell nuclei. Proc. Nat. Acad. Sci. USA 39:991-999. 

 Cachon, J. 



1964. Contribution a l'etude des Peridiniens parasites. Ann. 

 Sci. Nat. Zool. Fr., Ser. 12, 6:1-158. 

 Chatton, E. 



1910. Sur l'existence de Dinoflagelles parasites coelomiques. 

 Les Syndinium chez les Copepodes pelagiques. C. R. Acad. 

 Sci. Paris, 151:654-656. 

 Chatton, E. 



1920. Les Peridiniens parasites. Morphologie, reproduction, 



ethologie. Arch. Zool. Exp. Gen. 59:1-475. 

 Chatton, E. 



1921. Sur un mecanisme cinetique nouveau: la mitose syndi- 

 nienne chez les Peridiniens parasites plasmodiaux. C. R. 

 Acad. Sci. Paris, Ser. D, 173:859-862. 

 Chatton, E. 



1952. Classe des Dinoflagelles ou Peridiniens. In P. P. 

 Grasse (editor), Traite de Zoologie, Vol. 1, p. 309-390. 

 Masson et Cie, Paris. 

 Chatton, E., and R. Poisson. 



1931. Sur l'existence, dans le sang des Crabes de Peridiniens 

 parasites: Hematodinium perezi n.g., n. sp. (Syndinidae). 

 C. R. Soc. Biol. 105:553-557. 

 Du Praw, E. J. 



1968. Cell and molecular biology. Academic Press, N.Y. 

 Herzog, M., S. von Boletzky, and M.-O. Soyer. 



1984. Ultrastructural and biochemical nuclear aspects of 

 eukaryote classification: independent evolution of the dino- 

 flagellates as a sister group of the actual eukaryotes? 

 Origins Life 13:205-215. 



Hollande, A. 



1975. Etude comparee de la mitose syndinienne et de celle 

 des Peridiniens libres et des Hypermastigines infrastructure 

 et cycle evolutif des Syndinides parasites de Radiolaires. 

 Protistologica 10:413-451. 



Jepps, M. W. 



1936-37. On the protozoan parasites of Calanus finmarchicus 

 in the Clyde Sea area. Q. J. Microsc. Sci. 79:589-662. 

 Johnson, P. T. 



1985. Parasites of benthic amphipods: microsporidans of 

 Ampelisca agassizi (Judd) and some other gammarideans. 

 Fish. Bull., U.S. 83:497-505. 



1986. Parasites of benthic amphipods: ciliates. Fish. Bull., 

 U.S. 84:204-209. 



Loeblich, A. R., III. 



1976. Dinoflagellate evolution: speculation and evidence. J. 

 Protozool. 23:13-28. 



Maclean, S. A., and C. L. Ruddell. 



1978. Three new crustacean hosts for the parasitic dino- 

 flagellate Hematodinium perezi (Dinoflagellata: Syndinidae). 

 J. Parasitol. 64:158-160. 

 Manier, J.-F., A. Fize, and H. Grizel. 



1971. Syndinium gammari n. sp. peridinien Duboscquodinida 

 Syndinidae, parasite de Gammarus locusta (Lin.) Crustace 

 Amphipode. Protistologica 7:213-219. 

 Newman, M. W., and C. A. Johnson. 



1975. A disease of blue crabs (Callinectes sapidus) caused by 

 a parasitic dinoflagellate, Hematodinium sp. J. Parasitol. 

 61:554-557. 

 Ris, H., and D. F. Kubai. 



1974. An unusual mitotic mechanism in the parasitic proto- 

 zoan Syndinium sp. J. Cell Biol. 60:702-720. 

 Rizzo, P. J., AND L. D. Nooden. 



1974. Isolation and partial characterization of dinoflagellate 

 chromatin. Biochim. Biophys. Acta 349:402-414. 

 Siebert, A. E., and J. A. West. 



1974. The fine structure of the parasitic dinoflagellate Haplo- 

 zoon axiothellae. Protoplasma 81:17-35. 

 Stickney, A. P. 



1978. A previously unreported peridinian parasite in the eggs 

 of the northern shrimp, Pandalus borealis. J. Invertebr. 

 Pathol. 32:212-215. 

 Wu, R. S., S. Tsai, and W. M. Bonner. 



1982. Patterns of histone variant synthesis can distinguish 

 G from Gj cells. Cell 31:367-374. 



614 



