1. University of Gdańsk, Faculty of Biology, Department of Invertebrate Zoology and Parasitology , ul. Wita Stwosza 59, 80-308 Gdańsk , Poland
2. University of Gdańsk, Faculty of Oceanography and Geography, Institute of Oceanography, Prof. Krzysztof Skóra Hel Marine Station , ul. Morska 2, 84-150 Hel , Gdańsk Poland