Biological Invasions: European Smelt Osmerus eperlanus (L.) and Microsporidium Glugea hertwigi Weissenberg, 1911

摘要

The paper presents the phenomenology of European smelt Osmerus eperlanus and microsporidium Glugea hertwigi invasion into a new habitat, Lake Syamozero (Karelia), where neither of the species occurred before. The invasion history falls into four phases. The first, latent, phase started with a spontaneous invasion of the lake by smelt and lasted until the first fish showed up in catches (1968-1970). The second phase (from 1971 to 1980) was characterized by the population explosion of the invader. The smelt became the dominant species in the fish community, while the native plankton feeder, the vendace Coregonus albula, became an endangered species. The third phase (from 1980 to 1991) was marked by the population explosion of the microsporidium Glugea hertwigi and subsequent epizootic development. The fourth phase (from 1991 to present) is distinguished by the decreasing population of the invasive species, the smelt and the microsporidium Glugea hertwigi, and the recovery of the native vendace population.