A new aquatic beetle family, Meruidae, from Venezuela (Coleoptera: Adephaga)

Abstract

Abstract. An unknown beetle collected in the Territorio Federal Amazonas, Venezuela, and designated as belonging to a new family, is described (as Meru phyllisae gen.n., sp.n.) and illustrated by line drawings and scanning electron micrographs. The new family, Meruidae, is diagnosed and assigned to the suborder Adephaga with a discussion of some characters and likely phylogenetic affinities. With a body length of 0.85-0.9 mm, M. phyllisae is the smallest known member of aquatic Adephaga. Based on the observed skeletal and behavioural characters to date, the taxon appears to represent the sister clade to the remaining families of Dytiscoidea, but also has features suggesting a close relationship among Noteridae and/or Haliplidae. A description and photographs of the habitat are included, with a list of other associated water beetle taxa. Some observations on the behaviour of captive beetles are given. The minute 'comb-clawed cascade beetles' are known only from the type locality, El Toboga´n, where streams flow among exposed areas of bedrock in the geologically ancient Guyana Shield region.

Global diversity of water beetles (Coleoptera) in freshwater

“…The single known species lives at the gravelly margins (interstitial) of mountain streams. -Literature: Beutel et al (2006), Spangler & Steiner (2005).…”

The systematic position of Aspidytidae, the diversification of Dytiscoidea (Coleoptera, Adephaga) and the phylogenetic signal of third codon positions

“…In addition to the three large families of aquatic Adephaga, several isolated taxa have been recognized, which have apparently undergone very limited diversification. This includes the trout stream beetles (Amphizoidae) with five species in the genus Amphizoa ; the squeak beetles (Hygrobiidae) including six species of Hygrobia ; the recently described cliff water beetles (Aspidytidae) with two species in the genus Aspidytes ; and Meruidae with a single species in Venezuela (Spangler and Steiner 2005, species not included here). These small families have widely disjunct distributions, posing a most interesting problem with respect to their geographical origin, age and phylogenetic relationships.…”

Three new genera of acidocerine water scavenger beetles from tropical South America (Coleoptera, Hydrophilidae, Acidocerinae)

“…Nothing is known about the biology of this species except that it was collected from the margin of the Rio Coromoto, the infamous locality for many water beetle species including the family Meruidae (see Spangler and Steiner 2005). …”