Aquatic beetle diversity from Volcán Tacaná, Mexico: altitudinal distribution pattern and biogeographical affinity of the fauna

Abstract

Results of an aquatic beetle survey at Volcán Tacaná, Mexico, are presented with five altitudinal levels in a monthly sampling regime, aiming to estimate both diversity and altitudinal distribution patterns of the aquatic beetle fauna. The first list of aquatic beetle species from this mountain is presented, comprising 40 species in 32 genera and nine families, with four species recorded for the first time from Mexico and six recorded for the first time from Chiapas. The aquatic beetle fauna is characterized by Elmidae with 20 species, Dytiscidae with eleven species, Dryopidae with three, and Epimetopidae, Hydraenidae, Hydrophilidae, Gyrinidae, Lutrochidae, and Noteridae with one species each. The species composition through the sampled altitudinal gradient (670–1,776 m) was not homogeneous, with the elmid genera Macrelmis, Heterelmis, Microcylloepus, and Austrolimnius present at all levels, while Hexanchorus, Neoelmis, and Onychelmis were present at levels 1–3 (673–1,214 m); dytiscids were mostly present at levels 4 and 5 (1,619–1,776 m), and dryopids were present only at levels 1–3. A Parsimony Analysis of Endemicity supports a general partition between altitudinal levels 1–3 and levels 4 + 5.

Ralph W. Holzenthal – a mentor and friend retires

“…Many of his former mentees submitted articles to this volume, to show their gratitude and respect for Ralph’s life work. The topics he thus influenced range from faunal surveys and checklists ( Cavalcante-Silva et al 2022 ; Chuluunbat et al 2022 ; Houghton 2022 ; Luna-Luna et al 2022 ) and ecological studies ( Houghton et al 2022 ; Ríos-Touma et al 2022 ) to descriptive taxonomy ( Bueno-Soria et al 2022 ; Cavalcante-Silva et al 2022 ; Martins et al 2022 ; Pereira et al 2022 ; Ramírez-Carmona et al 2022 ; Rázuri-Gonzales et al 2022 ) and systematic revisions ( Blahnik and Andersen 2022 ; Sganga et al 2022 ; Thomson et al 2022a , b ).…”