A hydrostatic function of the accessory respiratory organs in air-breathing fishes.

Abstract

ACCESSORY respiratory organs in fishes have generally been thought to be concerned with breathing atmospheric air1. That, like any other gas-filled space, they can also be connected with the perception of hydrostatic pressure has not been reported earlier. In fishes, perhaps the very existence of a swim-bladder, which takes the major role in regulating the density of the fish2 and functioning as a hydrostatic organ3, has diverted attention from other gas-filled organs which may have a similar function.