DNA barcoding and faunistic criteria for a revised taxonomy of Italian Ephemeroptera

Abstract

Mayfly (Ephemeroptera) systematics has considerably changed over the years, but many questions have yet to be answered. The synergistic connection between traditional knowledge and new data sources, producing increasingly complex information, has become a compelling issue for modern taxonomy. Molecular tests and the use of reliable reference sequence libraries may constitute effective complements to the traditional method in guiding recognition of species and giving information about taxonomic incongruences which require further examination. In the present study, we sought to verify the current Italian mayfly nomenclatural system through DNA barcoding and relevant points to reliably manage the available amount of morpho-ecological and molecular data are discussed. We investigated COI (Cytochrome oxidase I) sequence variation in 163 individuals of Italian mayflies, 126 of which were previously assigned to 24 morphologically recognised species, and 37 could be attributed only to generic taxonomic entities ("sp.", "cf." or "gr."). DNA barcoding statistical tests for species delimitation hypotheses based on genetic distances and inferred gene trees were integrated with GenBank searches and surveys of the historical literature to better understand the knowledge acquired on the status and diversity of the investigated taxa. Combined criteria to define three categories of reliability were then assessed. Concurrent data allowing unambiguous identification were attained for only eight species. High intraspecific genetic distances (> 3%) and a lack of reliable reference material or convincing taxonomic information evidenced 29 critical states, deserving further investigation. Solid species names, potential cryptic species and entities about which little is known are pointed out for a future upgrade/reorganisation of the taxonomy of Italian Ephemeroptera.

Reports of Baetidae (Ephemeroptera) species from Tafna Basin, Algeria and biogeographic affinities revealed by DNA barcoding

“…The Algerian haplotypes present low genetic distance with specimens from southern France, confirming the link for this species between North African and South European populations. The sequences from Sicily, Italy (BP_Gp2) were not assigned to Baetis pavidus with certainty by Tenchini et al (2018) and may represent an undescribed species close to B. pavidus or, alternatively, may be correctly associated with B.…”

Taxonomy of Baetis Leach in Israel (Ephemeroptera, Baetidae)

“…Baetislutheri has a wide distribution in the West Palearctic (Bauernfeind and Soldán 2012) but recent molecular analysis has shown that it may constitute a complex of closely related species (Tenchini et al 2018). Koch (1988) reported it from Lebanon and Syria, but these reports may refer to B.golanensis .…”

Habitat requirements affect genetic variation in three species of mayfly (Ephemeroptera, Baetidae) from South Africa

“…Since the 1980s there has been an exponential increase in the number of studies on cryptic species, partly due to the introduction of the PCR, which resulted in the increasing availability of DNA sequences (Bickford et al 2007). Molecular (DNA) methods are valuable in resolving morphologically cryptic lineages and have been used extensively in discriminating species with few or no morphological differences (Jackson and Resh 1998, Rutschmann et al 2014, Leys et al 2016, Tenchini et al 2018. Within the Ephemeroptera, cryptic lineages have been discovered in numerous families through electrophoretic studies (Sweeney and Funk 1991, Zloty et al 1993, Funk and Sweeney 1994 and, more recently, DNA sequence data (Williams et al 2006, Ståhls and Savolainen 2008, Pereira-da-Conceicoa et al 2012.…”