Behavior
B
Buccal Pumping
Quick Definition
Active gill ventilation in which muscles alternately expand and compress the buccal and opercular cavities to draw water over the gills.
📖 Full Definition
Buccal pumping is the active, muscular mode of gill ventilation used by most teleost fish. The buccal cavity (mouth) and opercular cavity (gill chamber) expand and contract alternately, maintained by muscles attached to the mandible and opercular bones. During inspiration, the buccal cavity expands and the mouth opens, drawing water in. Mouth closure and buccal compression then force water through the gill slits into the expanding opercular cavity. Opercular flap closure then forces the water out over the gills in a nearly continuous unidirectional flow. Buccal pumping allows fish to breathe while stationary or resting.
💡 Examples & Context
A resting flatfish on the seafloor breathes using pure buccal pumping — drawing water in through the upper nostril and expelling it through the opercular opening, with no swimming required.