A taxonomic and ecological review of Pseudocloeon glaucum (Agnew)(Ephemeroptera: Baetidae)

Pseudocloeon masai (Lugo-Ortiz and McCafferty), P. nadineae (Lugo-Ortiz and McCafferty) and P. quintum (Agnew) are junior subjective synonyms of P. glaucum (Agnew). Larvae of P. glaucum manifest a wide range of variation in mouthpart morphology, particularly with respect to the development of the distomedial process of segment 2 of the labial palps, body size, general body colour and abdominal colour pattern. Such variation is observed in different cohorts and populations, and explains why several names have been applied to the same species. Larvae of P. glaucum also have considerable ecological tolerance, accounting for the abundance and widespread distribution of the species in the Afrotropical Region. New records from Kenya, Lesotho, Namibia and Zimbabwe are provided

A non-paraphyletic classification of the afrotropical genus Acanthiops Waltz & McCafferty (Ephemeroptera: Baetidae)

Acanthiops Waltz & McCafferty (Ephemeroptera: Baetidae) is shown to be a monophyletic grouping defined by an anteromedially emarginate and laterally expanded and flattened pronotum in the larva. Attempts to restrict the concept of Acanthiops to Ac. marlieri (Demoulin) and re-erect Afroptiloides Gillies, syn. n., for Ac. elgonensis Lugo-Ortiz & McCafferty, Ac. griffithsi Lugo-Ortiz & McCafferty, Ac. tsitsa Barber-James & McCafferty, Ac. variegatus (Gillies), Ac. varius (Crass) and Ac. zomba Lugo-Ortiz & McCafferty, are shown to be based on inconsistent and inadequate morphological features that result in a paraphyletic taxonomy. The unofficial separate treatment of Ac. cooperi (Gillies & Wuillot) and Ac. erepens (Gillies) under Platycloeon Gillies & Wuillot is also shown to be paraphyletic. Acanthiops faro Barber-James & McCafferty, sp. n., is described from larvae from Guinea, and is distinguished by the combination of a papillate projection on labial palp segment 2, small tubercles on terga 1-8 and abdominal colour pattern. Acanthiops io Lugo-Ortiz & McCafferty, sp. n., is described from larvae from the Democratic Republic of Congo, and is distinguished by the combination of a papillate projection on palp segment 2, elongate tubercles on terga 1-9 and abdominal colour pattern. The larva of Ac. erepens (Gillies) is redescribed to incorporate morphological features and variability previously not accounted for, and larvae originally assigned to Baetis cataractae Crass are shown to be equivalent to Ac. erepens. New locality data or emendations on locality data are provided for Ac. griffithsi, Ac. tsitsa Barber-James & McCafferty and Ac. varius (Crass)

Cryptic variation in an ecological indicator organism: mitochondrial and nuclear DNA sequence data confirm distinct lineages of <it>Baetis harrisoni</it> Barnard (Ephemeroptera: Baetidae) in southern Africa

Abstract Background Baetis harrisoni Barnard is a mayfly frequently encountered in river studies across Africa, but the external morphological features used for identifying nymphs have been observed to vary subtly between different geographic locations. It has been associated with a wide range of ecological conditions, including pH extremes of pH 2.9–10.0 in polluted waters. We present a molecular study of the genetic variation within B. harrisoni across 21 rivers in its distribution range in southern Africa. Results Four gene regions were examined, two mitochondrial (cytochrome c oxidase subunit I [COI] and small subunit ribosomal 16S rDNA [16S]) and two nuclear (elongation factor 1 alpha [EF1α] and phosphoenolpyruvate carboxykinase [PEPCK]). Bayesian and parsimony approaches to phylogeny reconstruction resulted in five well-supported major lineages, which were confirmed using a general mixed Yule-coalescent (GMYC) model. Results from the EF1α gene were significantly incongruent with both mitochondrial and nuclear (PEPCK) results, possibly due to incomplete lineage sorting of the EF1α gene. Mean between-clade distance estimated using the COI and PEPCK data was found to be an order of magnitude greater than the within-clade distance and comparable to that previously reported for other recognised Baetis species. Analysis of the Isolation by Distance (IBD) between all samples showed a small but significant effect of IBD. Within each lineage the contribution of IBD was minimal. Tentative dating analyses using an uncorrelated log-normal relaxed clock and two published estimates of COI mutation rates suggest that diversification within the group occurred throughout the Pliocene and mid-Miocene (~2.4–11.5 mya). Conclusions The distinct lineages of B. harrisoni correspond to categorical environmental variation, with two lineages comprising samples from streams that flow through acidic Table Mountain Sandstone and three lineages with samples from neutral-to-alkaline streams found within eastern South Africa, Malawi and Zambia. The results of this study suggest that B. harrisoni as it is currently recognised is not a single species with a wide geographic range and pH-tolerance, but may comprise up to five species under the phylogenetic species concept, each with limited pH-tolerances, and that the B. harrisoni species group is thus in need of taxonomic review.</p