There are more species of beetles than all other insects combined, but most are terrestrial rather than aquatic.
There are more species of beetles than all other insects combined, but most are terrestrial rather than aquatic.
Most aquatic beetles live in still rather than flowing water.
Some beetle larvae have gills or obtain oxygen through their body's surface but others must sometimes travel to the water's surface to obtain air.
Many adult aquatic beetles carry an air bubble with them. This air bubble must be periodically be replenished with oxygen at the water's surface.
Only highly specialized beetles in very cold streams can obtain sufficient oxygen without having to go to the surface for air.
Illustration courtesy of B.C. Kondratieff, Colorado State University.
