Measurement of gill water flow in Squalus acanthias using the dye-dilution technique

Abstract

The Hamilton-Stewart dye-dilution technique was modified to permit the measurement of gill water flow (V) in the dogfish, Squalus acanthias. Validation of the procedure was obtained by perfusion of the gills via the spiracles with measured volumes of water. One hundred and seven determinations were performed in 20 fish. V averaged 26. 6[plus or minus] 1. 7 l/kg per hr. V increased with increasing body mass. O2 extraction from water by the dogfish is about 20%, a value similar to O2 extraction from air by man.