signal crayfish without one claw, an invasive non-native species in hancza lake, poland.

animal aquatic bottom claw close closeup crawfish crayfish crustacea deep diving environment eye fauna focus food fresh freshwater glacial green haacza hancza invasive invertebrate lake leniusculus macro marine natural nature nonnative one outdoor pacifastacus photo podlasie poland pond river sand scuba selective shell shellfish signal species stream suwalszczyzna underwater water wild wildlife