Studies on Myxozoa have emphasized their potential impact on aquatic animal health but less on ecological aspects. In this investigation, we assess the importance of host and latitudinal variations in the morphometry of spores of Ceratomyxa Thélohan, 1892 (Myxozoa) from the gall bladder of 3 ling Genypterus (Pisces; Ophidiidae) species. Discriminant analyses indicated that several morphospecies of Ceratomyxa coexist in these hosts, despite the fact that the specific level of taxonomic resolution of each spore was not attempted. At least 4 species, i.e., Ceratomyxa hokarari Meglitsch, 1960; Ceratomyxa inversa Meglitsch, 1960; Ceratomyxa laxa Meglitsch, 1960; and Ceratomyxa elongata Meglitsch, 1960 occur in the study area, and at least 2 species co-occur in each host and geographical location. The most widespread pattern found is that spores are larger in golden ling (Genypterus blacodes) and spore size decreases with increasing latitude; this may be associated with the species composition of these assemblages, as well as with the habitat and diet segregation of the host species.