|Dorsal view of S. senegalensis|
|Profile view of S. senegalensis|
Spercheus is a genus of aquatic beetles which are placed in a family of their own, Spercheidae. About 20 species are known from around the world, with the majority being from the Oriental and Afrotropical Realms.
These beetles are usually less than half a centimeter long and their larvae are found in shallow still water with rich vegetation. They do not swim but hang below the water surface and filter-feed on algae. The larvae are triangular in shape, the outline resembling that of antlion larvae. Larvae of many species are also filter feeders on plant matter but some Australian species feed on worms, snails , and other small invertebrates. Females build a silken-egg case which they attach to their mid-tibiae and held by the hind legs, carried below the abdomen. These beetles were formerly placed in the family Hydrophilidae but are distinctive. The front of the head is notched and the 7–9 segmented antenna has the terminal 3–4 segments club like and an enlarged fourth segment. The elytra are very convex and one or two abdominal segments extend beyond the apex. They have 5 tarsal segments on all legs.