A new species of Chloromyxum (Myxozoa: Chloromyxidae) from the gall bladder of Eurycea spp. (Caudata: Plethodontidae) in North America.

A previously undescribed species of Chloromyxum (Myxozoa: Chloromyxidae) was found in plasmodia adhering to the epithelium of the gall bladders in salamanders of the genus Eurycea (Caudata: Plethodontidae) from Arkansas and Texas (USA) in November, December, and January, 1987 to 1994. Bivalved spores of Chloromyxum salamandrae sp. n. from Eurycea multiplicata griseogaster (type host) were subspherical, with a mean size +/- SD of 8.3 +/- 0.3 x 7.7 +/- 0.4 (7.8 to 8.8 x 7.0 to 8.2) microns (n = 20), and had a shape index (length/width) of 1.07 +/- 0.03 (1.02 to 1.14). The valves measured 0.8 to 1.0 micron thick and had 10 to 12 external striations each. Each of the four polar capsules were piriform, with a mean size +/- SD of 4.0 +/- 0.1 x 2.6 +/- 0.1 (3.8 to 4.2 x 2.4 to 2.8) microns (n = 20), and there appeared to be about four coils of each polar filament. The sporoplasm was irregular in shape and appeared to be binucleate. Adherent plasmodia observed in winter months were small, with a mean size +/- SD of 31.5 +/- 6.3 x 24.9 +/- 2.6 (20 to 40 x 20 to 30) microns (n = 20), and contained zero to eight disporoblastic spores each. The myxozoan occurred in nine of 14 E. multiplicata griseogaster, three of eight E. multiplicata multiplicata, and two of 12 E. neotenes. This represents the first report of a Chloromyxum sp. from Amphibia in the Western hemisphere.