Species of the genus Chloromyxum Mingazzini (Myxozoa: Myxosporea) infecting burbot (Lota lota L.)

Three different species of the genus Chloromyxum Mingazzini were found in burbot (Lota lota L.) collected in south-west Bohemia (Czechoslovakia). Comparison with existing records revealed that one species could be identified as C. pseudomucronatum Kashkovskiy, 1966. Found in the urinary bladder, it had subspherical spores with fine surface ridges and polysporic plasmodia. The two other myxosporea were established as new species: C. lenorae n. sp. was found in the kidney, renal corpuscles, renal tubules and interstitium, and had ellipsoid spores with surface ridges barely perceptible in the light microscope but clearly revealed by transmission electron microscopy. In the polysporic plasmodia, spores developed in pansporoblasts. C. reticulatum n. sp. was found in the gall bladder. It had polysporic plasmodia and spherical spores (average size 8.1 m in diameter) with a unique surface structures: elevated crests marking off irregular fields which appeared as a reticulum. In five of the fish infected with C. lenorae, bloodstream myxosporean stages of an extrasporogonic cycle were found. Further research is needed to determine whether they are stages of Sphaerospora cristata Shulman, 1962, a species also found in two of the burbot examined, or stages belonging to the Chloromyxum life cycle.