p. 201 - 217 POSSIBILITIES OF OSMOTIC ADAPTATION ON THE SHRIMP Palaemon adspersus TO LOW SALINITY MEDIA Margareta Craciun 1), V. Craciun 1), I. Neacsu 1) and Gabriela Dimoftache 2) 1) Biological Research Center Iasi 2) Institut Roumain de Recherches Marines Constanta Abstract The effects of low salinities (8 and 5%)on hydric and mineral balance of males and females of Palaemon adspersus were studied. In hypo-saline media, both sexes showed noticeable possibilities of osmoregulation due to modifications of passive permeability of the cell membranes and by stimulation of the active ionic transport mechanisms.