JOHNSON: MICROSPORIDANS OF AMPELISCA AGASSIZI 



Table 4. — Microsporidans in amphipods other than Ampelisca agassizi. 



The microsporidan of Ampelisca vadorum Mills 

 resembled that of Unciola spp., but fully developed 

 spores were not seen (Fig. 8). Muscle, tegmental 



8 



4Mi 



•»• 



x*" ^-* 



glands, and oocytes were infected. Often, groups of 

 microsporidans had "used up" the host tissue, and 

 appeared like groups of extracellular, closely knit, 

 vegetative and sporulating stages, but some of these 

 groups were unmistakably in the shape of tegmen- 

 tal glands and oocytes and were in the correct 

 anatomical positions. In one case, muscle fibers were 

 still present adjacent to the mass of microsporidans 

 and in another, microsporidans infected a recogni- 

 zable tegmental gland. Host reactions to the micro- 

 sporidans had not occurred in the few infected A. 

 vadorum available for study. 



More than 35 specimens each of the following 

 species were sectioned and examined, but micro- 

 sporidans were not found: Anonyx sarsi Steel & 

 Brunei (36 specimens), Byblis serrata Smith (316 

 specimens), Casco bigelowi (Blake) (60 specimens), 

 Corophium crassicorne (Bruzelius) (50 specimens), 

 Harpinia propinqua Sars (116 specimens), Orcho- 

 menella minuta Kr0yer (64 specimens), Phox- 

 ocephalus holbolli Kr0yer (73 specimens), Pseuduni- 

 cola obliquua (Shoemaker) (46 specimens), and 

 Rhepoxynius epistomus (Shoemaker) (249 

 specimens). 



% 



i 



Figure 8— Ampelisca vadorum: Vegetative and prespore 

 stages of a muscle-infecting microsporidan. Bar =10 jjm 



DISCUSSION 



Bulnheim (1975) and Sprague (1977) have hsted 

 and discussed the various microsporidans reported 

 from amphipods. Most of the hosts are freshwater 

 and estuarine forms, and depending on the species 



503 



