A new interstitial species of diving beetle from tropical northern Australia provides a scenario for the transition of epigean to stygobitic life (Coleoptera, Dytiscidae, Copelatinae)

摘要

Exocelinasaltusholmesensissp. n. is described from a single female collected in Holmes Jungle Reserve near Darwin in the Northern Territory, Australia. Phylogenetically, the new species is sister to a clade containing the epigean Exocelinaferruginea (Sharp, 1882) and Exocelinapunctipennis (Lea, 1899) but well characterized by its smaller size, the much smaller eyes, vestigial wings and paler surface. Exocelinasaltusholmesensissp. n. was collected from a small pool in an intermittent and temporary small creek. The collecting circumstances suggest that this is an interstitial species, with morphological characters interpreted as adaptations to a strongly hidden if not mostly subterranean lifestyle.