p. 201 - 215

L'EQUILIBRE HYDRO-MINERAL CHEZ LE SANDRE (Stizisteidon 
lucioperca L.1758) TRANSFERE DE L'EAU DOUCE EN MILIEUX
MIXO-MESOHALINIS ET INVERSEMENT

Ion Neeacsu 1)Valeriu Craciun2) Margareta Craciun 1) et
Iulian Trandafirescu1) Centre de Recherches Biologiques Iasi
2)Institut Roumain de Recherches Marines Constanta


Abstract 
A sudden transfer of the pike perch from freshwater to sea 
water (17 g%0)causes some deep and irreversibile changes in
their hydromineral equilibrium leading to the death of the 
animals. A hydration of cells, a substantial accumulation
of sodium in cells and an important loss of potasium and
calcium take place. The animals transferred gradually
survive by establishing a new hydro-mineral equilibrium.
When the fishes adapted to sea water are suddently brought
back to freshwater, the hydro-mineral equilibrium specific
to freshwater is established again, after minor modifications
in the repartion of water and ions.