Myxidium rhodei Leger, 1905 (Cnidaria, Myxosporea): Age-Related, Seasonal, and Spatial Dynamics and Long-Term Survey of Common Roach Rutilus rutilus Infection in Chivirkuy Bay of Lake Baikal

Abstract

The myxosporean Myxidium rhodei Leger, 1905 is a common parasite of Palaearctic cyprinids localized primarily in the Bowman capsules of fish kidneys. In Lake Baikal, roach Rutilus rutilus has been infected with myxosporidium M. rhodei at a high prevalence (94–100%) and intensity of invasion (up to 6000 pseudocysts) in 1999–2021. In this work, we analyzed the age-related, seasonal, long-term dynamics and the spatial distribution of M. rhodei infestation of roaches in Chivirkuy Bay of Lake Baikal. The parasite begins to be registered in yearlings, then the intensity of invasion of roach M. rhodei increases, reaching a maximum in middle-aged fish, and decreases in older fish. M. rhodei has an annual development cycle in roaches. Fluctuations in the infection of M. rhodei in the studied fish over 25 years of observation correlate with long-term changes in the hydrological regime of Lake Baikal.