EPIZOOTIOLOGY AND HISTOPATHOLOGY OF Chloromyxum trijugum (MYXOSPORA: MYXOSPORIDA) IN CENTRARCHID FISHES FROM IOWA

Abstract

Abstract:The gall bladder parasite, Chloromyxum trijugum, shows marked host specificity within the sunfish family Centrarchidae. During 1977-78 80% of 230 bluegills (Lepomis macrochirus) in Iowa were infected. Prevalence in green sunfish (L. cyanellus) was lower (17%); one of 2 specimens of the hybrid L. macrochirus X L. cyanellus was infected; orangespotted sunfish (L. humilis) and hybrids (L. humilis X L. macrochirus) were not infected. Intensity of infection in bluegills varied throughout the year. Prevalence of free-floating Plasmodia in bluegill gall bladders was highest (100%) during winter and spring months, and decreased to 40-50% during summer and fall. Prevalence of attached plasmodia may remain 80-100% throughout the year. Sporulation and plasmotomy were observed year-round. Plasmodia were attached to underlying epithelial cells by pseudopodia-like projections and were associated with various stages of breakdown in the mucosal layer.

A New Myxozoan From Feral Goldfish (Carassius Auratus)

“…In his description, Mitchell (1978) notes several features that are inconsistent with C. auratum, including large pigmented trophozoites and smaller spores with 15-16 ridged striae per valve. However, in a subsequent description of the parasite, the size of spore and number of ridges is less ) (see Table I).…”

“…More than 100 species of Chloromyxum have been described from marine and freshwater fishes (Lom and Dykova, 1993 Hoffman, 1999); C. trijugum (Xiao and Desser, 2000); C. truttae (Herrick, 1936;Mitchell et al, 1980;Mamyshev et al, 1981); Chloromyxum wardi, and Chloromyxum salamandrae (Upton et al, 1995); 4 marine species Chloromyxum ovatum (Jameson, 1929), Chloromyxum levigatum (Jameson, 1931), Chloromyxum kabatai (Moser and Noble, 1977), and Chloromyxum subsphaericum (Schulman, 1966;Moser and Noble, 1977); and several unidentified species (see Gowen, 1983;Kent et al, 1994;Hoff et al, 1997;Hoffman, 1999).…”

“…commersonii, but Mitchell (1978) describes the parasite from 5 cyprinid species, excluding goldfish. In his description, Mitchell (1978) notes several features that are inconsistent with C. auratum, including large pigmented trophozoites and smaller spores with 15-16 ridged striae per valve.…”

“…Unlike C. cristatum, however, C. auratum had 4 equal polar capsules and mictosporic plasmodia. Moreover, C. auratum spores were larger and had fewer extrasutural ridges than those documented in the type description of C. cristatum as well as the other chloromyxa described from North American cyprinids, including the only junior synonym of C. cristatum reported from North America, Chloromyxum catastomi Kudo, 1919 (see Table I) (Mitchell, 1978;Listebarger and Mitchell, 1980;Lom and Dyková, 1993). Chloromyxum catostomi also has 'polar capsules almost of same size', though Kudo (1919) noted that its striations ran parallel to the sutural ridge, inconsistent with both C. cristatum and C. auratum.…”

Ceratomyxa hungarica n. sp. and Chloromyxum proterorhini n. sp. (Myxozoa: Myxosporea) from the freshwater goby Proterorhinus marmoratus (Pallas)

“…Unfortunately, the rather low intensity of infection prevented the collection of data on the developmental stages. Although Mitchell et al (1980) found the sporogonic plasmodia of C. trijugum attached to the gall-bladder wall, the early developmental stages should be looked for in the bile duct, as suggested by Davis (1985), who discovered plasmodia of the also gall-bladder parasite Zschokkella russeli in this site. In the case of parasites of this type, the presence of blood stages is unlikely, although Lom et al (1988) did not preclude this possibility.…”