Gas-filled Spaces Research Articles

Responses of Some Marine Plankton Animals to Changes in Hydrostatic Pressure

IT has generally been thought that aquatic animals, which lack gas-filled spaces in their bodies, would not perceive variations in hydrostatic pressure due to small changes in depth, since their bodies are permeated with fluid of very slight compressibility1. Only animals possessing gas-filled spaces, such as fishes, with their swim bladders2, and certain aquatic insects, with special pressure gauges connected to the tracheal system3, had been shown to respond to pressure changes, until recently. Then the discovery that decapod larvae swim upwards, in response to pressure increases4, suggested that tests for pressure sensitivity should be carried out on animals not known to possess gas organs.