No abstract

Although studies on snow algae and macroinvertebrates have been frequently conducted on snow patches, no attention have been paid to ubiquitous microinvertebrates which in other cold habitats reach high biomass and play various trophic roles. The aim of this study was to search microinvertebrates in seasonal snow patches in Mt. Gassan, in northern Japan, and identify factors determining their distribution associated with snow algal blooming of various coloration (red, green, and yellow). Microscopic observation revealed presence of two major groups of microinvertebrates Tardigrada and Rotifera. Tardigrades and rotifers were the most abundant and frequent in green snow formed by blooming of Chloromonas sp., but few in red or yellow snow. Body length of tardigrades increased through the melting season and animals laid eggs on colored snow. These results suggest tardigrades successfully grew and reproduced on snow patches. Taking into account the presence of tardigrades and rotifers mostly in green snow (only few found in red and yellow) with high densities, we may assume green snow patches constitute important and unique low-temperature ecosystems for microinvertebrates in a temperate mountainous forest. Area of snow algae blooming worldwide are unrecognized novel habitat for tardigrades and rotifers.