Functional Morphology of the Tuna Gill

Abstract

The tuna gill has a number of structural modifications from that for typical teleosts. A brief summary is given of a series of studies which describe these modifications and attempt to analyse the functioning of the tuna gill. Included is a study of "ram" ventilation - swimming with the mouth agape. The major part of the presentaiton deals with the unique respiratory blood pathway of the tunas and our hypothesis that it greatly reduces the blood pressure drop across the gill.