Osmotic tolerance and adaptation to hypotonic medium of Echinorhynchus gadi (Acanthocephala, Echinorhynchidae)]

Minimum of the osmotic pressure in the intestine of the cod corresponds to the osmotic pressure of sea water of 10%. The sorbtion level of neutral red by intact E. gadi remained practically unchanged after their maintenance in sea water of 8-10 to 30% during 24 hours (ecological optimum). Specimens of E. gadi transferred from 10 to 4% displayed compensatory recovery of the normal sorbtion level of the dye by the 5th-6th day of the experiment. The ability of Acanthocephala possessing extreme eutelia to a physiological adaptation is indicative of its not obligatory participation of mitotic processes in the acclimation.