Taxonomic revision of the Ethiopian genus Canthyporus (Coleoptera Dytiscidae)

Abstract

-The genus Canthyporus Zimmermann, 1919, is revised. A total of 35 species are recognized, all of them distributed within the Ethiopian Region, and with a centre of diversity in the South African Western Cape province. Descriptions of all species are given together with illustrations of habitus and male and female genitalia. A key to species (males), distribution maps, and ecological information are provided. Four new species are described from South Africa: Canthyporus aenigmaticus n.sp., C. nimius n.sp., C. turneri n.sp., and C. wewalkai n.sp. The species C. congener , is regarded as valid and not as a junior synonym of C. canthydroides (Régimbart, 1895). Lectotypes are designated for the following ten names: C. alvei , C. consuetus Omer-Cooper, 1965, C. latus Omer-Cooper, 1965, C. lowryi Omer-Cooper, 1965, C. nebulosus Omer-Cooper, 1965, C. similator Zimmermann, 1923, C. simulator Guignot, 1959, C. testaceus Zimmermann, 1923, Hydroporus collaris Boheman, 1848, and Hydroporus hottentottus Gemminger & Harold, 1868. A parsimony analysis based on 32 morphological characters found 28 shortest trees. Monophyly of the genus Canthyporus is supported mainly by the presence of an anterior ligula on the ventral side of the elytron. Four species groups are recognized within the genus: (1) canthydroides group, including ten species in Namibia and South Africa; (2) exilis group, including four species in Lesotho and South Africa; (3) hottentottus group, including 18 species from the Democratic Republic of the Congo, Ethiopia, Kenya, Lesotho, Madagascar, South Africa, Swaziland, Tanzania, and Zimbabwe; and (4) lateralis group, including three species from South Africa. Riassunto -Revisione tassonomica del genere Afrotropicale Canthyporus (Coleoptera Dytiscidae).Il genere Canthyporus Zimmermann, 1919 è revisionato. In totale sono riconosciute 35 specie, tutte sono distribuite nella regione Afrotropicale, con un centro di diversità nella Western Cape province (Sud Africa). Sono fornite le descrizioni di tutte le specie con illustrazioni dell'habitus, dei genitali maschili e femminili. Sono inoltre forniti una chiave per l'identificazione dei maschi delle specie, mappe di distribuzione e informazioni ecologiche. Sono descritte quattro nuove specie provenienti dal Sud Africa: Canthyporus aenigmaticus n.sp., C. nimius n.sp., C. turneri n.sp., and C. wewalkai n.sp. Canthyporus congener Omer-Cooper, 1956 è considerata come specie valida e non un sinonimo di C. canthydroides (Régimbart, 1895). Sono designati i lectotipi dei seguenti dieci taxa: C. alvei , C. consuetus Omer-Cooper, 1965, C. latus Omer-Cooper, 1965, C. lowryi Omer-Cooper, 1965, C. nebulosus Omer-Cooper, 1965, C. similator Zimmermann, 1923, C. simulator Guignot, 1959, C. testaceus Zimmermann, 1923, Hydroporus collaris Boheman, 1848 e Hydroporus hottentottus Gemminger & Harold, 1868. Un'analisi cladistica condotta secondo il criterio della parsimonia e basata su 32 caratteri morfologici ha prodotto 28 alberi. La monofilia del genere Canthyporus è supportat...

Evolution of Blind Beetles in Isolated Aquifers: A Test of Alternative Modes of Speciation

“…To meet this assumption the ancestral species must have had widespread and largely overlapping geographical distributions. As already noted by Darwin [30], and confirmed by other studies [31]–[37], most dytiscid water beetles indeed have very widespread overlapping distributions, are able to fly large distances and are capable of rapidly colonizing newly available habitats, such as roadside ditches, ponds or temporary streams. Moreover, intrinsic factors of species, such as size or pre-adaptations to subterranean life, could make certain species more likely colonizers than others.…”

Deeper knowledge of shallow waters: reviewing the invertebrate fauna of southern African temporary wetlands

“…Whereas the Noteridae are largely permanent water inhabitants, a number of Dytiscidae are temporary pond specialists, and others are found there occasionally or temporarily as adults. Canthyporus species occur across a spectrum of freshwater habitats, including seepages, streams and ponds, both permanent and temporary (Biström & Nilsson, 2006;Bilton et al, 2015). This genus is particularly diverse in the Cape, where most of its species are endemic.…”

[Dytiscidae (Coleoptera) of Gabon (10th part): addenda and corrigenda]

“…Diagnose: espèce appartenant au groupe 12 villiersi (sensu Biström, 1997) par la présence d'appareil stridulatoire et par la forme du pénis; l'habitus est très proche de H. niger Gschwendtner, 1938 et le pénis se caractérise surtout dorsalement par la présence à la base de deux larges lobes latéraux et au sommet une expansion lobiforme préapicale.…”

“…Diagnose: espèce appartenant au groupe 11 oblongipennis (sensu Biström, 1997) par la présence d'appareil stridulatoire et par la forme du pénis; elle est très proche de H. lintrarius Guignot, 1958et de H. omentatus Guignot, 1950 par les caractères suivants: habitus semblable, rebord frontal complet de la tête, ongles protarsales du mâle moyennement épaissies, pénis en vue dorsal et paramères très semblables. Elle diffère de H. lintrarius surtout par la forme du pénis en vue latérale pour la moitié distale plus rétrécie avec l'apex acuminé et de H. omentatus surtout par la taille plus faible (L 4,40-4,56, la 2,84-2,88 mm: Biström, 1997 Description: L 3,25-3,64, la 2,00-2,26 mm, (holotype: L 3,36 mm; la 2,02 mm).…”

“…Elle diffère de H. lintrarius surtout par la forme du pénis en vue latérale pour la moitié distale plus rétrécie avec l'apex acuminé et de H. omentatus surtout par la taille plus faible (L 4,40-4,56, la 2,84-2,88 mm: Biström, 1997 Description: L 3,25-3,64, la 2,00-2,26 mm, (holotype: L 3,36 mm; la 2,02 mm). Forme régulièrement ovale avec l'apex des élytres pointu.…”