Taxonomic description of six species of pelagic, freshwater ciliates from the Order Choreotrichida collected from Lake Ontario, Canada

Aloricate ciliates are essential members of the pelagic microbial foodweb and are easy to identify in samples, yet the taxonomic database is insufficient and many species have yet to be described. Individuals from the Phylum Ciliophora Doflein, 1901, Order Choreotrichida Small and Lynn, 1985 were collected from the epilimnion (upper 20m) of Lake Ontario in the spring, summer and autumn of 1990 and 1991. They were fixed and silver-stained. Here we describe the morphospecies of five species from the genus Rimostrombidium Jankowski, 1978: Rimostrombidium kyoskota n.sp., Rimostrombidium pentagrammum n.sp., Rimostrombidium trioeumekes n.sp., Rimostrombidium paravelox Kahl, 1932 n.comb., Rimostrombidium brachykinetum Krainer, 1995 and one from the genus Pelagostrobilidium Petz et al., 1995: Pelagostrobilidium limnospirale n.sp. Increasing the taxonomic database allows for a more detailed monitoring of the biodiversity and energy transfer within a system, which in turn can better inform ecosystem management decisions.