Morphometric data from spores of ten myxosporean species were statistically analysed to explore myxosporean intraspecific variation in measurements when obtained from a sample from: (1) the same plasmodium, (2) different plasmodia from the same host and (3) different host individuals and localities. In some cases, significant differences in spore dimensions were found between samples from the same plasmodium, highlighting the difficulty of obtaining representative measurements of myxosporean spore. In addition, significant differences in spore dimensions were found when plasmodia from the same site of infection were compared, suggesting that measurements of spores should come from several different plasmodia of the sampling to increase the reliability of the morphology data. Moreover, significant differences in spore dimensions were observed for most spore dimensions when data were compared between localities. In all cases, there was clear overlap in ranges of dimensions even when means differed significantly. The present statistical analysis shows that intraspecific morphometric variation of myxosporean species commonly occurs, highlighting the importance of reporting ranges of measurements for a species, not just the mean dimensions, and taking into account all evidence when assigning or describing myxosporean species., Yanhua Zhai, Christopher M. Whipps, Zemao Gu, Qingxiang Guo, Zizhen Wu, Hongmei Wang, Yang Liu., and Obsahuje bibliografii
A new highly pathogenic muscle-infecting species of the genus Myxobolus Bütschli, 1882 is described from the Prussian carp, Carassius gibelio (Bloch, 1782) using spore morphology and SSU rDNA sequence data. Phylogenetic analyses elucidated relationship of the newly described Myxobolus lentisuturalis to other Myxobolus species and supported its position of an independent species.
The original description of Myxobolus longisporus Nie et Li, 1992, the species infecting gills of Cyprinus carpio haematopterus L., is supplemented with new data on the spore morphology and pathogenicity. Spores are elongate pyriform with pointed anterior end, 15.7 (15.5-16.5) µm long, 6.7 (6-8) µm wide and 5.5 µm thick. Sutural ridge is straight and narrow. Mucus envelope is lacking. Two equal-sized elongate pyriform polar capsules are 8.5 µm long and 2.5 µm wide with convergent long axes. Polar filament coiled perpendicularly to the long axis of the capsule makes 9 (8-10) turns. Posterior end of polar capsules exceeds mid-spore by 15-20%. Cyst-like plasmodia are localised in the gill secondary lamellae. The infection is described in adult big host specimens. Gross lesions manifested as dark red colouration of gill tissues were restricted to the ventral part of the first gill arches. Remarkable site specificity (apical part of secondary lamellae) was observed in the course of development of microscopic lesions. M. longisporus is characterised also on the molecular level using sequences of SSU rRNA gene. Phylogenetic analysis based on these sequences has allowed clearer phylogenetic relationships to be established with other species of the genus Myxobolus sequenced to date.