Osmoregulation in Some Freshwater Prawns

Abstract

I. A freshwater prawn, Palaemonetes antennarius, from Italy, is shown to have a different level of salt concentration in the blood and urine compared with that of the brackish water P. varians and Palaemon longirostris in Britain. 2. Although this prawn lives in fresh water the urine is isosmotic with the blood and is produced at a rate of about 2% body weight/hr. 3. An uptake of salte from a very dilute medium has been demonstrated in saltdepleted animals