|Minute bog beetles|
The minute bog beetle is a small and obscure family (Sphaeriusidae) of beetle typically found along the edges of streams and rivers, where it feeds on algae. There are 19 species in a single genus Sphaerius, occurring on all continents except Antarctica.
The overall form of the beetle is convex, glossy, dark brown or black with some markings possible. The head is prominent, with relatively large eyes set far apart, and capitate antennae. Total length ranges from 0.5 to 1.2 mm.
The beetles occur in a variety of damp environments, including mud, under stones, among plant roots and leaf litter, and in mosses in bogs (thus the name). They store some air underneath their elytra.
Females produce a single large egg.
The family was previously known as Sphaeriidae, but the name is now used for a family of freshwater clams. The name Microsporidae and genus Microsporus has very recently been superseded by Sphaeriusidae and Sphaerius. The position of the family within Coleoptera has also changed a number of times.