Alexander's Method of Determining Swimbladder Volumes Modified for Living Physoclist Fish

Abstract

A method to determine the swimbladder volume of living physoclists from its change in volume with change in applied pressure once the gas has been compressed sufficiently to remove the constraint of the swimbladder walls is given. The density of the fish at test depth was calculated from its mass, the seawater density, and the increase in volume of the fish with decrease in pressure from test depth to that causing neutral buoyancy.