engleski

Population characteristics of the stone crayfish from natural undisturbed habitat and habitat under anthropogenic pressure

The stone crayfish (Austropotamobius torrentium) is a native European species inhabiting streams at higher altitudes with rocky bottoms, with a large number of shelters. Within Croatia stone crayfish can be found in waterbodies of the Black Sea drainage, with some populations recorded in the Adriatic Sea drainage. In the last few decades stone crayfish populations are disappearing due to negative anthropogenic impact upon their habitats and the presence of invasive non-indigenous crayfish species. This study was conducted in order to get insight into the stone crayfish population characteristics in the natural and anthropogenically affected habitats. To that end 7-days field work was carried out along different parts of a stream ; the natural course and the course under anthropogenic influence (channelized part and part within the settlement). Data on the habitat characteristics, population density, crayfish morphometrics, size structure, sex ratio and body condition were collected and analysed, and comparisons among different parts of the stream made. Expectedly, stone crayfish population in the natural part of the stream was estimated as the biggest with crayfish in the best body condition. The results confirm the high sensitivity of stone crayfish to environmental changes and indicate the great importance and necessity to preserve natural habitats of this species.

Austropotamobius torrentium; population size; morphometry; habitat protection

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