Osmoregulation and the regulation of the free amino acid concentration in the haemolymph of the larvae of Aeshna cyanea (Müller) (Anisoptera: Aeshnidae)

In the study of the osmoregulation of the haemolymph of the larvae of A. cyanea, two kinds of experiments are used. The organisms not being fed during the course of the experiments, the effect of starvation is investigated. Changes of the haemolymph osmotic pressure as a function of the time spent in the experimental media, and the relation between the osmotic pressure of the internal and external media are measured. In all experiments the concentration of free amino acids is determined. The results indicate that free amino acids compensate for changes in osmotic pressure of the haemolymph.