Ionic regulation inCrangon vulgaris(Fabr.) (Crustacea, Natantia) from brackish water

Abstract

The hyper-hypoosmotic (isosmotic at 23‰) shrimp Crangon vulgaris was found to maintain Ca²⁺ and K⁺ more concentrated than the medium in 5-25‰, Na⁺ and Cl⁻ more concentrated in the range 5–30(23)‰ and less concentrated in higher salinities. Mg²⁺ was held at a very low level throughout the saUnity range. The importance of various mechanisms (low permeability, active ion transport and hypo-osmotic urine) in assisting this efficient ion regulation is discussed.