Evolution and island endemism of morphologically cryptic Baetis and Cloeon species (Ephemeroptera, Baetidae) on the Canary Islands and Madeira

Abstract

Summary The Canary Islands and Madeira are reportedly home to seven recognised species of baetid mayflies (Ephemeroptera, Baetidae), two of which also occur on the European mainland. Their species status remains unsure, and loss of habitat suggests they are of conservation concern. We applied morphological characters and a general mixed Yule‐coalescent (gmyc) model analysis of the cytochrome c oxidase subunit 1 (cox1) gene to delineate putative species within morphologically cryptic species groups Baetis (Rhodobaetis) and Cloeon dipterum s.l. We used a three‐gene mitochondrial data set (1450 base pairs) to infer phylogenetic relationships and a molecular clock calibrated using island geological ages to infer colonisation history. Genetic and morphological evidence indicated the presence of 12 putative species, 11 of which were endemic to the islands. Only Baetis atlanticus, on Madeira, also occurs on the European mainland. Two lineages (B. pseudorhodani s.l. and B. canariensis s.l.) appear to have arisen in the past 15 million years (mya) and diversified in parallel throughout the Canary Islands. Within the canariensis lineage, sister species occur on the island of Gran Canaria and in North Africa. Pronounced island endemism contradicts previous taxonomic work, which reported a depauperate fauna that included several mainland species. Recent diversification among islands and a close link to North Africa suggest a complex evolutionary history. Owing to their small population size and ongoing habitat alteration, several of these island endemics are among the most endangered aquatic insects in Europe.

discomark: nuclear marker discovery from orthologous sequences using draft genome data

“…The use of the marker set for C. dipterum developed here resulted in a fully resolved phylogenetic tree in contrast to the mitochondrial tree of Rutschmann et al . (). The phylogeny of the Cloeon ‐species complex presented here also is in complete agreement with species tree reconstructions based on 59 nDNA markers (Rutschmann et al ., ).…”

“…Rutschmann et al . (used three mitochondrial genes); Leys et al . (used cytochrome c oxidase subunit 1 ( cox1 ) gene)].…”

“…; Rutschmann et al . ). As input to design the primer pairs, we used whole‐genome sequencing data of C. dipterum L. 1761 and expressed sequence tags (EST) of Baetis sp.…”

Labiobaetis from the Kingdom of Saudi Arabia (Insecta, Ephemeroptera, Baetidae)

“…The percentage of trees in which the associated taxa clustered together is shown next to the branches (Bootstrap with 1000 replicates). We used 3.5% sequence divergence (measured by Kimura 2-parameter (K2P)) as the maximal value for intraspecific divergence (Ball et al 2005; Gattolliat et al 2015; Rutschmann et al 2014; Rutschmann et al 2017; Webb et al 2012). As part of the sequenced specimens came from the same population, the intraspecific divergence is expected to be even clearly lower than the limit.…”

Molecular phylogeny and morphological analysis resolve a long‐standing controversy over generic concepts in Ecdyonurinae mayflies (Ephemeroptera: Heptageniidae)

“…The scarcity of phylogenetic information for Heptageniidae contrasts with the situation in other families, the phylogeny of which has been resolved recently at least to some extent (e.g. Gattolliat et al ., ; O'Donnell & Jockusch, ; Ogden et al ., ; Rutschmann et al ., ), as well as the situation in Ephemeroptera as a whole (Ogden & Whiting, ; Ogden et al ., ).…”