Antiporus is one of the dytiscid “diving beetles” having larvae and adults that are active swimmers. The larvae have a spoon-like “nose” supporting side barbs. The adults are oval and streamlined, up to 5mm long, with 11-segmented antennae, and the last segment of the foreleg is longer than the other tarsal segments.
Antiporus are most common in ponds, wetlands and slow-flowing weedy streams.
The dytiscid beetles are predators, feeding on other pond invertebrates.
The presence of Antiporus is more likely to reflect pond-like habitat conditions rather than any particular water quality conditions. They have medium to low tolerance values of 5 (hard bottom sites) and 3.5 (soft bottom sites).