Stygobitic
Guides
Bidessini
Bidessini is a tribe of predaceous diving beetles within the family Dytiscidae, comprising at least 40 genera and over 630 described species. Members are small to minute aquatic beetles found across diverse freshwater habitats worldwide, with notable radiations in Australia, South America, and Madagascar. The tribe includes both surface-dwelling (epigean) and subterranean (stygobitic) species, with several genera exhibiting convergent adaptations to groundwater environments.
Stygoparnus
Comal Springs dryopid beetle (for sole species S. comalensis)
Stygoparnus is a monotypic genus of dryopid beetles containing the single species Stygoparnus comalensis, known as the Comal Springs dryopid beetle. The genus is endemic to central Texas spring systems fed by the Edwards Aquifer. Its sole member is a federally endangered, subterranean-obligate aquatic beetle with vestigial eyes and reduced pigmentation. The genus represents the only known aquatic lineage within the family Dryopidae.