Plumatella repens (Linnaeus, 1758) (Bryozoa: Phylactolaemata) collected from an alpine lake in the Italian dolomites

Abstract From 1982 to 2006, seven sampling surveys were performed in Red Bay of the alpine Lake Tovel (Brenta Dolomites, Italy) to investigate the bryozoan fauna. The record of small and round floatoblasts was noteworthy as they were not comparable to those produced by any presently known Bryozoa species. Three different types of floatoblasts characterized by almost circular shape were distinguished using morphological traits. All recorded specimens were attributed to the species Plumatella repens (Linnaeus, 1758). The dimensions of type 1 are the smallest ever recorded for Italy. The particular morphology and smallness of floatoblasts were investigated. The authors deem that the features of type 1 in the geographically isolated population of Plumatella repens from Red Bay may be due to constant low water temperature. Therefore, they are proposing for type 1 the name Plumatella repens type dolomitica.