ACCLIMATION TRIALS OF JUVENILE ITALIAN STURGEON TO DIFFERENT SALINITIES - MORPHOPHYSIOLOGICAL DESCRIPTORS

In this study the first experimental trials of acclimation to saliniti es of the Italian sturgeon Acipenser naccarii are described. Prelimina ry observations regarding some morphological features of the gut, kidn ey and gills following exposure to 20 and 30 parts per thousand salini ty are reported, and compared with those displayed by many teleosts in hyper- and hypoosmoregulation. Results are discussed with regard to t he osmoregulatory mechanisms and to the physiological limits of adapta bility of this species in the second year of its life cycle. Within th e Acipenseridae, Acipenser naccarii is generally considered a euryhali ne species, but nothing is known about its mechanisms of osmotic homeo stasis. This species could be a good candidate for aquaculture in fres h and brackish waters owing to the recent success obtained in artifici al reproduction. (C) 1995 The Fisheries Society of the British Isles.