A laboratory experiment was carried out to test the combined effects of ration size [1 vs 3% body weight (b.w.)] and
temperature (15±2 vs 22±2°C) on growth and metabolic parameters of 80 juvenile noble crayfish (Astacus astacus
L.). The maximum daily consumption (C, g·g-1) and respiration rate (R, g O2·g-1·d-1) were used to calculate the
growth scope (i.e. the difference between maximum daily energy consumption and energy costs at a given temperature).
The conversion of C and R into a food-equivalent unit (g food·g-1·d-1) allowed their comparison. Results
showed that crayfish grew faster when fed 3% b.w. while temperature seemed to play a less relevant role on growth
variables, affecting the moulting frequency only. Crayfish A. astacus fed ad libitum showed a relative insensitivity
of the metabolic parameters (oxygen uptake, R and C) within the analysed range of temperatures, possibly
reflecting its distribution across a broad variety of habitats with different thermal regimes. In the present study,
A. astacus displayed some characteristics specific of a K-selected species, such as slow to moderate growth and low
juvenile survival rates
