63 research outputs found
Toward a DNA Taxonomy of Alpine Rhithrogena (Ephemeroptera: Heptageniidae) Using a Mixed Yule-Coalescent Analysis of Mitochondrial and Nuclear DNA
Aquatic larvae of many Rhithrogena mayflies (Ephemeroptera)
inhabit sensitive Alpine environments. A number of species are on the IUCN Red
List and many recognized species have restricted distributions and are of
conservation interest. Despite their ecological and conservation importance,
ambiguous morphological differences among closely related species suggest that
the current taxonomy may not accurately reflect the evolutionary diversity of
the group. Here we examined the species status of nearly 50% of European
Rhithrogena diversity using a widespread sampling scheme of
Alpine species that included 22 type localities, general mixed Yule-coalescent
(GMYC) model analysis of one standard mtDNA marker and one newly developed nDNA
marker, and morphological identification where possible. Using sequences from
533 individuals from 144 sampling localities, we observed significant clustering
of the mitochondrial (cox1) marker into 31 GMYC species.
Twenty-one of these could be identified based on the presence of topotypes
(expertly identified specimens from the species' type locality) or
unambiguous morphology. These results strongly suggest the presence of both
cryptic diversity and taxonomic oversplitting in Rhithrogena.
Significant clustering was not detected with protein-coding nuclear PEPCK,
although nine GMYC species were congruent with well supported terminal clusters
of nDNA. Lack of greater congruence in the two data sets may be the result of
incomplete sorting of ancestral polymorphism. Bayesian phylogenetic analyses of
both gene regions recovered four of the six recognized
Rhithrogena species groups in our samples as monophyletic.
Future development of more nuclear markers would facilitate multi-locus analysis
of unresolved, closely related species pairs. The DNA taxonomy developed here
lays the groundwork for a future revision of the important but cryptic
Rhithrogena genus in Europe
第931回千葉医学会整形外科例会
Background
Larvae of the Holarctic mayfly genus Rhithrogena Eaton, 1881 (Ephemeroptera, Heptageniidae) are a diverse and abundant member of stream and river communities and are routinely used as bio-indicators of water quality. Rhithrogena is well diversified in the European Alps, with a number of locally endemic species, and several cryptic species have been recently detected. While several informal species groups are morphologically well defined, a lack of reliable characters for species identification considerably hampers their study. Their relationships, origin, timing of speciation and mechanisms promoting their diversification in the Alps are unknown.
Results
Here we present a species-level phylogeny of Rhithrogena in Europe using two mitochondrial and three nuclear gene regions. To improve sampling in a genus with many cryptic species, individuals were selected for analysis according to a recent DNA-based taxonomy rather than traditional nomenclature. A coalescent-based species tree and a reconstruction based on a supermatrix approach supported five of the species groups as monophyletic. A molecular clock, mapped on the most resolved phylogeny and calibrated using published mitochondrial evolution rates for insects, suggested an origin of Alpine Rhithrogena in the Oligocene/Miocene boundary. A diversification analysis that included simulation of missing species indicated a constant speciation rate over time, rather than any pronounced periods of rapid speciation. Ancestral state reconstructions provided evidence for downstream diversification in at least two species groups.
Conclusions
Our species-level analyses of five gene regions provide clearer definitions of species groups within European Rhithrogena. A constant speciation rate over time suggests that the paleoclimatic fluctuations, including the Pleistocene glaciations, did not significantly influence the tempo of diversification of Alpine species. A downstream diversification trend in the hybrida and alpestris species groups supports a previously proposed headwater origin hypothesis for aquatic insects
First report of Cloeon vanharteni Gattolliat & Sartori, 2008 (Baetidae, Ephemeroptera) in the Maghreb
Cloeon vanharteni Gattolliat & Sartori, 2008 was newly discovered in the framework of our study of Ephemeroptera in the Draa basin, located in the southern region of the High Atlas in Morocco. This discovery is rather unexpected as the species was never reported outside the Arabian Peninsula and Levant; it is thus the first record for the Maghreb. The identification was based on morphological evidence and confirmed by the mitochondrial COI barcode
Caminante, No Hay Camino, Se Hace Camino al Andar: On a Creative Research Project in Urban Planning
This article looks back at a creative research project conducted in Geneva, Switzerland, which, by experimenting between art and science, sought to understand how citizen narratives can participate in the making of an urban plan. The approach presented here brought together geographers, architects, and novelists. Citizen narratives produced at writing workshops imagined the city of the future in ways that significantly contrasted with visions gathered from events organised by public authorities. These narratives were taken up by the novelists, who helped produce a piece of fiction containing the power to reveal the qualities of the present. This piece has since become a novel. By discovering what their future city could be, participants in this project were led to identify the places that should be preserved. Their narratives thus helped identify an ordinary heritage that could be included in an urban planning document. This reflective look at a project that gradually took shape could be useful to anyone wishing to conduct creative research in urban planning, particularly from the perspective of a more inclusive city
Molecular phylogeny and timing of diversification in Alpine Rhithrogena (Ephemeroptera: Heptageniidae).
BACKGROUND: Larvae of the Holarctic mayfly genus Rhithrogena Eaton, 1881 (Ephemeroptera, Heptageniidae) are a diverse and abundant member of stream and river communities and are routinely used as bio-indicators of water quality. Rhithrogena is well diversified in the European Alps, with a number of locally endemic species, and several cryptic species have been recently detected. While several informal species groups are morphologically well defined, a lack of reliable characters for species identification considerably hampers their study. Their relationships, origin, timing of speciation and mechanisms promoting their diversification in the Alps are unknown.
RESULTS: Here we present a species-level phylogeny of Rhithrogena in Europe using two mitochondrial and three nuclear gene regions. To improve sampling in a genus with many cryptic species, individuals were selected for analysis according to a recent DNA-based taxonomy rather than traditional nomenclature. A coalescent-based species tree and a reconstruction based on a supermatrix approach supported five of the species groups as monophyletic. A molecular clock, mapped on the most resolved phylogeny and calibrated using published mitochondrial evolution rates for insects, suggested an origin of Alpine Rhithrogena in the Oligocene/Miocene boundary. A diversification analysis that included simulation of missing species indicated a constant speciation rate over time, rather than any pronounced periods of rapid speciation. Ancestral state reconstructions provided evidence for downstream diversification in at least two species groups.
CONCLUSIONS: Our species-level analyses of five gene regions provide clearer definitions of species groups within European Rhithrogena. A constant speciation rate over time suggests that the paleoclimatic fluctuations, including the Pleistocene glaciations, did not significantly influence the tempo of diversification of Alpine species. A downstream diversification trend in the hybrida and alpestris species groups supports a previously proposed headwater origin hypothesis for aquatic insects
Electrogena brulini sp. nov. and E. vipavensis Zurwerra & Tomka, 1986 syn. nov. revealed by integrative taxonomy of E. gridellii (Grandi, 1953) (Ephemeroptera: Heptageniidae)
Wagner, Andre, Vuataz, Laurent, Sartori, Michel (2017): Electrogena brulini sp. nov. and E. vipavensis Zurwerra & Tomka, 1986 syn. nov. revealed by integrative taxonomy of E. gridellii (Grandi, 1953) (Ephemeroptera: Heptageniidae). Zootaxa 4362 (3): 359-384, DOI: https://doi.org/10.11646/zootaxa.4362.3.
Introduction to the Special Issue “Aquatic Insects: Biodiversity, Ecology, and Conservation Challenges”
In non-marine environments, insects comprise one of the most species-rich and abundant groups of organisms [...
New species of Labiobaetis Novikova & Kluge from New Guinea (Ephemeroptera, Baetidae): a never-ending story of diversity
Investigations of material collected partly in 1999 and mainly between 2006 and 2016 in New Guinea, mostly along the high, central mountain chain of the island, further increased our knowledge of the diversity of the genus Labiobaetis Novikova & Kluge on this island. Previously, 37 species were reported from New Guinea. We have identified six new species using a combination of morphology and genetic analysis (COI). They are described and illustrated based on their larvae. Five of the six new species belong to the group petersorum, which is endemic to the island. Additionally, Labiobaetis xeniolus Lugo-Ortiz & McCafferty is also assigned to this group. The morphological characterisation of the group petersorum is enhanced, and a key to all species of this group is provided. Complementary descriptions and remarks to the morphology of known species of the group petersorum are provided. Additionally, a genetic analysis (COI) including most species and several additional Molecular Operational Taxonomic Units (MOTUs) of the group petersorum is discussed. One of the new species belongs to the group vitilis. The morphological characterization of this group is slightly enhanced, and the obtained COI sequence was added to the genetic analysis of the group petersorum. The total number of Labiobaetis species worldwide is augmented to 162
FIGURES 100–103 in Electrogena brulini sp. nov. and E. vipavensis Zurwerra & Tomka, 1986 syn. nov. revealed by integrative taxonomy of E. gridellii (Grandi, 1953) (Ephemeroptera: Heptageniidae)
FIGURES 100–103. Eggs of Electrogena brulini (Fig. 100–101) and Electrogena gridellii (Figs 102–103). Figs 100, 102: general view; Figs 101, 103: emphasis on the micropyle
FIGURES 32–39 in Electrogena brulini sp. nov. and E. vipavensis Zurwerra & Tomka, 1986 syn. nov. revealed by integrative taxonomy of E. gridellii (Grandi, 1953) (Ephemeroptera: Heptageniidae)
FIGURES 32–39. Nymph of Electrogena brulini (Fig. 32); legs and parts of legs of Electrogena brulini (Figs 33, 35–37) and Electrogenagridellii (Figs 34, 38,39).Fig.32:habitus of ayoung nymph in latero-dorsal view; Figs33–34:dorsal face of fore-, mid and hind legs; Fig 35: ventral face of fore-, mid and hind legs, emphasis on a pectinate setae; Figs 36, 38: dorsal face of forefemora, emphasis on bristles; Figs 37, 39: dorsal face of hind femora, emphasis on bristles. Arrows in Fig. 32: example of different markings already visible in young nymphs
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