Apparatus for measurements of physiological parameters in fish

A special apparatus for simultaneous recording of a fish gill movement, ECG and water flow through a fish mouth was designed, developed and experimentally tested. A pair of single channel force transducers with linear dependence of the output voltage upon the load 0.5 mV/mN over the nominal range of 0-70 mN at a bridge excitation of 5V was used for recording the curves of gill movements. Wires fixed with the fishing hooks into the fish body and on the other side connected to the amplifier were used for ECG recordings. A pressure transducer recorded a water flow through a fish mouth. We recommend our set up as a simple and useful tool for recording the described physiological parameters in experiments with fish.