Aquatic oligochaetes are well recognized bioindicators of quality of sediments and water in watercourses and lakes. However, the difficult taxonomic determination based on morphological features compromises their more common use in eco-diagnostic analyses. To overcome this limitation, we investigated molecular barcodes as identification tool for broad range of taxa of aquatic oligochaetes. We report 185 COI and 52 ITS2 rDNA sequences for specimens collected in Switzerland and belonging to the families Naididae, Lumbriculidae, Enchytraeidae and Lumbricidae. Phylogenetic analyses allowed distinguishing 41 lineages separated by more than 10 % divergence in COI sequences. The lineage distinction was confirmed by Automatic Barcode Gap Discovery (ABGD) method and by ITS2 data. Our results showed that morphological identification underestimates the oligochaete diversity. Only 26 of the lineages could be assigned to morphospecies, of which seven were sequenced for the first time. Several cryptic species were detected within common morphospecies. Many juvenile specimens that could not be assigned morphologically have found their home after genetic analysis. Our study showed that COI barcodes performed very well as species identifiers in aquatic oligochaetes. Their easy amplification and good taxonomic resolution might help promoting aquatic oligochaetes as bioindicators for next generation environmental DNA biomonitoring of aquatic ecosystems.

The Swiss Barcode of Life initiative (SwissBOL) aims to inventory the genetic biodiversity in Switzerland using a short DNA sequence. DNA barcoding provides an additional tool for species identification that complements traditional morphological approaches. We report on the establishment of a DNA barcode library for Plecoptera, taxa that are of great importance as bioindicators of water quality and that often present difficulties in species-level identification for larvae and female specimens. Non-destructive DNA extraction, PCR amplification and sequencing of part of the mitochondrial gene Cytochrome Oxidase I (COI) was conducted for 440 individuals (one to eight per species) belonging to 90 species (of the 112 reported from Switzerland). Intra and interspecific distances were calculated and gene trees reconstructed. In most cases, COI was efficient in delimiting stonefly species. Some doubtful specimens were subsequently re-examined and a few misidentifications were found, especially in some problematic groups in the genus Leuctra Stephens, 1836. Larger genetic distances in some species (e.g. Leuctra nigra (Olivier 1811)) indicate the possible presence of sibling species, while in a few cases closely related species are genetically difficult to separate (within the Leuctra fusca species group).

BackgroundFour plastid regions, rpoB, rpoC1, matK, and trnH-psbA, have been recommended as DNA barcodes for plants. Their success in delimiting species boundaries depends on the existence of a clear-cut difference between inter- and intraspecific variability. We tested the ability of these regions to discriminate among closely related species in seven genera of flowering plants with different generation times (trees, perennials, and annuals). To ensure a maximum coverage of intraspecific diversity, and therefore to better evaluate the resolution power of each barcode, we applied a population genetics approach by sampling three to 45 individuals per species over a wide geographical range.ResultsAll possible combinations between loci were analysed, which showed that using more than one locus does not always improve the resolution power. The trnH-psbA locus was most effective at discriminating among closely related species (Acer, Lonicera, Geranium, and Veronica), singly or in combination. For Salix, Adenostyles, and Gentiana, the best results were obtained with the combination of matK, rpoB, and trnH-psbA. No barcoding gap was found within six genera analysed, excepting Lonicera. This is due to shared polymorphisms among species, combined with very divergent sequences within species. These genetic patterns reflect incomplete lineage sorting and hybridization events followed by chloroplast capture.ConclusionsOur results strongly suggest that adding trnH-psbA to the two obligate DNA barcodes proposed by the CBOL plant-working group (matK and rbcL) should be mandatory for closely related species. In our sampling, generation time had no influence on DNA barcoding success, as the best and worst identification successes were found for the two tree genera (Acer, 64 % success and Salix, 86 % failure). Evolutionary histories are the main factor influencing DNA barcoding success in the studied genera.Electronic supplementary materialThe online version of this article (doi:10.1186/s12862-016-0678-0) contains supplementary material, which is available to authorized users.

This paper describes the previously unknown larva of Hydropsyche doehleri Tobias 1972. Species association was enabled by the fact that both larval and adult specimens were collected at the same location and that H. doehleri was the only Hydropsychidae collected at this site, based on light-trap samples of adults. In addition, association of larvae with adult males and females were performed using DNA sequence data from the mitochondrial cytochrome c oxidase region. Information on the morphology of the larva is given, and the most important diagnostic features separating H. doehleri from its sister taxon H. siltalai Döhler 1963 are discussed. In both species, gills are lacking on abdominal segment VII. In the context of the Hydropsychidae key of Waringer & Graf (2011), the two species can be separated by the morphology and coloration of the frontoclypeal apotome, and by their distribution patterns: whereas H. siltalai is widespread in Europe, H. doehleri has been reported from only France, Italy, and southern Switzerland (Tessin).                #We dedicate this paper to Univ. Prof. Dr Hans Malicky on the occasion of his 85th birthday.