Preliminary multispecies test of a model for non-lethal estimation of metabolic activity in freshwater crayfish

Abstract

We tested the applicability of electron transport system (ETS) derived from a single leg as a tool for non-lethal assessment of metabolicactivity in freshwater crayfish. ETS activity of the whole body and of a leg was measured in four crayfish (Arthropoda, Crustacea, Decapoda)species: two European (Astacus astacus, Austro- potamobius torrentium), and two North American (Orconectes limosus, Pacifastacusleniusculus). Mass scaling of whole body ETS activity (ETSwhole) and leg ETS activity (ETSleg) was not significantly different for the European A. astacus and the America O. limosus. Therefore common models were constructed and tested on the remaining two species. The ratio ETSwhole/ETSleg was significantly positively related to body mass. In the first model (model 1) ETSwhole was calculated from ETSleg multiplied by the ratio estimated from the known body mass. ETSwhole of A. torrentium was underestimated by this model, because they mature at smaller body size than the larger species. A direct relation between ETSleg and ETSwhole was therefore proposed as a general model (model 2), since they are correlated similarly in the studied species. The results show that model 2 is suitable for estimating the whole body ETS activity from leg ETS activity for the four investigated decapods.