Bifidochaetus, a new Arctic genus of freshwater Chaetonotida (Gastrotricha) from Spitsbergen revealed by an integrative taxonomic approach

2016 ◽  
Vol 30 (4) ◽  
pp. 398 ◽  
Author(s):  
Małgorzata Kolicka ◽  
Miroslawa Dabert ◽  
Jacek Dabert ◽  
Tobias Kånneby ◽  
Jacek Kisielewski

Gastrotricha is a cosmopolitan phylum of aquatic and semi-terrestrial invertebrates that comprises ~820 described species. To date, freshwater gastrotrichs have not been the subject of faunistic or taxonomic research in the polar regions. In this paper, we present the first species-level description of a freshwater gastrotrich from the Arctic (Svalbard Archipelago). Evidence from morphology, morphometry and molecular analyses reveals that the species represents a new genus in Chaetonotidae: Bifidochaetus arcticus, gen. et sp. nov. Taking into consideration many morphological similarities to Chaetonotus (Primochaetus) veronicae Kånneby, 2013 we propose to include C. (P.) veronicae in the newly established genus under the new combination Bifidochaetus veronicae (Kånneby, 2013), comb. nov. In the phylogenetic analysis based on nuclear 18S rRNA, 28S rRNA and mitochondrial cytochrome c oxidase subunit I sequence data, B. arcticus, gen. et sp. nov. is nested within the family Chaetonotidae, as the sister group to the genus Lepidochaetus Kisielewski, 1991. In this paper we also present new taxonomic characters useful for gastrotrich taxonomy: the pharynx-to-intestine length ratio (I) and the spine bifurcation ratio (B).

Zootaxa ◽  
2016 ◽  
Vol 4196 (4) ◽  
pp. 498 ◽  
Author(s):  
KRZYSZTOF ZAWIERUCHA ◽  
MAŁGORZATA KOLICKA ◽  
ŁUKASZ KACZMAREK

Tardigrada is phylum of micrometazoans widely distributed throughout the world, because of old descriptions and insufficient morphometric data, many species currently need revision and re-description. Tenuibiotus voronkovi (Tumanov, 2007) is tardigrade previously only recorded from the Svalbard archipelago. This species’ original description was based on two individuals with destroyed claws on the fourth pair of legs and a lack of complete morphometric data for buccal tube and claws. In this paper, we present a re-description of T. voronkovi, supplementing the original description using the original paratype and additional material from Svalbard: Spitsbergen, Nordaustlandet and Edgeøya. This species is characterised by two macroplacoids and a microplacoid, claws of Tenuibiotus type, dentate lunules under claw IV, and faint granulation on legs I–III and strong granulation on the legs IV. We include a new morphological description with microphotographs, morphometric, and molecular data (including: mitochondrial cytochrome c oxidase subunit I (COI), internal transcribed spacers (ITS1–5.8S rDNA–ITS2), and nuclear ribosome subunits 28S rRNA and 18S rRNA). These are the first published molecular data for the genus Tenuibiotus Pilato and Lisi, 2011, analysis of which indicated an affiliation of Tenuibiotus to the family Macrobiotidae. We found no differences in body size between individuals from different islands (Nordaustlandet and Edgeøya), but did observe variability in the eggs. After revision of the literature and the published figures, we concluded that Dastych’s (1985) report of T. willardi (Pilato, 1976) from Svalbard, was actually T. voronkovi, which has the greater distribution in Svalbard, and other Arctic locations, than previously believed. 


2012 ◽  
Vol 19 (4) ◽  
pp. 571-584 ◽  
Author(s):  
Marek Ruman ◽  
Katarzyna Kozak ◽  
Sara Lehmann ◽  
Krystyna Kozioł ◽  
Żaneta Polkowska

Abstract During last years an interest in the processes of transport and fate of pollutants to the polar regions located distantly from industrial centers, has significantly increased. The current analytical techniques enabling conducting studies prove that the Arctic regions (in the past considered as a pollution free area) have become an area of highly intensive anthropopresion. Svalbard archipelago stands out from the other polar regions due to its specific environmental conditions and geographic location, which results in becoming a reservoir of contamination in this area. Systematic environmental monitoring of arctic regions is extremely important due to an unique opportunity of observing a direct impact of pollution on the ongoing processes in the area of interest. In this way measurement data obtained are a valuable source of information, not only on changes occurring in the Arctic ecosystem, but also on estimated global impact of certain xenobiotics present in the environment. Furthermore, qualitative and quantitative studies on particular chemicals deposited in different regions of the Arctic ecosystem may constitute the basis for undertaking actions aimed at preventing negative effects caused by these pollutants.


2002 ◽  
Vol 80 (1) ◽  
pp. 94-99 ◽  
Author(s):  
Donald T Stewart ◽  
Neil D Perry ◽  
Luca Fumagalli

Previous morphological and cytological analyses have suggested that the arctic shrew (Sorex arcticus) as currently recognized may be two distinct species. Specifically, those studies demonstrated considerable differentiation between the putative subspecies S. a. maritimensis and one or both of the other two subspecies, S. a. arcticus and S. a. laricorum. Phylogenetic analysis of 546 base pairs of cytochrome b sequence data from 10 arctic shrews from across Canada indicates that maritimensis is the sister-group to arcticus + laricorum. Furthermore, there is considerable genetic divergence between maritimensis and the other two putative subspecies (~8–9%; Kimura's two-parameter distance). Given that maritimensis and arcticus + laricorum appear to be reciprocally monophyletic clades with considerable genetic divergence (i.e., greater than that between other recognized pairs of sister-species within the S. araneus–arcticus group), we propose that S. maritimensis be recognized as a distinct species. The proportion of third-position transversion substitutions between S. arcticus and S. maritimensis suggests that these two species shared a common ancestor approximately 2.4 million years ago.


2006 ◽  
Vol 20 (5) ◽  
pp. 503 ◽  
Author(s):  
Gregory D. Edgecombe ◽  
Gonzalo Giribet

Scutigeromorpha (‘house centipedes’) play a pivotal role in myriapod systematics in being the sister group to all other chilopods, but their internal phylogeny has not been comprehensively appraised since K. W. Verhoeff’s morphological investigations a century ago. Relationships between the three families of Scutigeromorpha are inferred based on a combined analysis of approximately 5.5 Kb of sequence data from five molecular markers (complete 18S rRNA, a 2.2-Kb fragment of 28S rRNA, 16S rRNA, cytochrome c oxidase subunit I, histone H3) and 33 ingroup morphological characters. Molecular data are available for 19 ingroup terminals representing 14 morphospecies that include the genera Scutigerina, Madagassophora (family Scutigerinidae), Sphendononema (family Pselliodidae), Scutigera, Thereuopoda, Thereuopodina, Thereuonema, Allothereua and Parascutigera (family Scutigeridae). Morphology resolves the southern African–Malagasy Scutigerinidae as sister to all other Scutigeromorpha, whereas rival sister-group relationships between the Neotropical–Afrotropical Pselliodidae and Scutigerinidae + Scutigeridae or Pselliodidae + Scutigerinidae and Scutigeridae are resolved by the molecular and combined analyses. Monophyly of Scutigeridae and Thereuoneminae are stable across a broad range of analytical parameters. Thereuoneminae is composed of two stable clades: an Allothereua + Parascutigera group, and a grouping of Thereuopoda, Thereuonema and Thereuopodina. Molecular and combined analyses resolve the genus Scutigerina and the morphospecies Scutigerina weberi as paraphyletic, in both cases with a Malagasy clade excluding populations from southern Africa.


2021 ◽  
Author(s):  
Congbo Song ◽  
Manuel Dall’Osto ◽  
Angelo Lupi ◽  
Mauro Mazzola ◽  
Rita Traversi ◽  
...  

Abstract. Understanding aerosol-cloud-climate interactions in the Arctic is key to predict the climate in this rapidly changing region. Whilst many studies have focused on submicron aerosol (diameter less than 1 μm), relatively little is known about the climate relevance of supermicron aerosol (diameter above 1 μm). Here, we present a cluster analysis of multiyear (2015–2019) aerodynamic volume size distributions with diameter ranging from 0.5 to 20 μm measured continuously at the Gruvebadet Observatory in the Svalbard archipelago. Together with aerosol chemical composition data from several online and offline measurements, we apportioned the occurrence of the coarse-mode aerosols to anthropogenic (two sources, 27 %) and natural (three sources, 73 %) origins. Specifically, two clusters are related to Arctic haze with high levels of black carbon, sulfate and accumulation mode (0.1–1 μm) aerosol. The first cluster (9 %) is attributed to ammonium sulfate-rich Arctic haze particles, whereas the second one (18 %) to larger-mode aerosol mixed with sea salt. The three natural aerosol clusters were: open ocean sea spray aerosol (34 %), mineral dust (7 %), and an unidentified source of sea spray-related aerosol (32 %). The results suggest that sea spray-related aerosol in polar regions may be more complex than previously thought due to short/long-distance origins and mixtures with Arctic haze, biogenic and likely snow-blowing aerosols. Studying supermicron natural aerosol in the Arctic is imperative for understanding the impacts of changing natural processes on Arctic aerosol.


2021 ◽  
Vol 21 (14) ◽  
pp. 11317-11335
Author(s):  
Congbo Song ◽  
Manuel Dall'Osto ◽  
Angelo Lupi ◽  
Mauro Mazzola ◽  
Rita Traversi ◽  
...  

Abstract. Understanding aerosol–cloud–climate interactions in the Arctic is key to predicting the climate in this rapidly changing region. Whilst many studies have focused on submicrometer aerosol (diameter less than 1 µm), relatively little is known about the supermicrometer aerosol (diameter above 1 µm). Here, we present a cluster analysis of multiyear (2015–2019) aerodynamic volume size distributions, with diameter ranging from 0.5 to 20 µm, measured continuously at the Gruvebadet Observatory in the Svalbard archipelago. Together with aerosol chemical composition data from several online and offline measurements, we apportioned the occurrence of the coarse-mode aerosols during the study period (mainly from March to October) to anthropogenic (two sources, 27 %) and natural (three sources, 73 %) origins. Specifically, two clusters are related to Arctic haze with high levels of black carbon, sulfate and accumulation mode (0.1–1 µm) aerosol. The first cluster (9 %) is attributed to ammonium sulfate-rich Arctic haze particles, whereas the second one (18 %) is attributed to larger-mode aerosol mixed with sea salt. The three natural aerosol clusters were open-ocean sea spray aerosol (34 %), mineral dust (7 %) and an unidentified source of sea spray-related aerosol (32 %). The results suggest that sea-spray-related aerosol in polar regions may be more complex than previously thought due to short- and long-distance origins and mixtures with Arctic haze, biogenic and likely blowing snow aerosols. Studying supermicrometer natural aerosol in the Arctic is imperative for understanding the impacts of changing natural processes on Arctic aerosol.


2014 ◽  
Vol 45 (3) ◽  
pp. 251-281 ◽  
Author(s):  
Jakob Damgaard ◽  
Felipe Ferraz Figueiredo Moreira ◽  
Tom A. Weir ◽  
Herbert Zettel

The phylogenetic relationships among selected species and genera of Gerrinae (Heteroptera: Gerridae) were investigated in a parsimony analysis of 2268 bp of DNA sequence data from the genes encoding COI + II, 16S rRNA and 28S rRNA. The taxa represented 12 of 15 recognized genera of Gerrinae and with outgroup taxa from all other subfamilies of Gerridae, including three of five recognized genera of Eotrechinae, which is considered the sister-group of Gerrinae. The resulting phylogeny shows that Gerrinae is not monophyletic, since a clade comprising Gerris, Aquarius, Limnoporus, Tachygerris, Eurygerris and Gigantometra is more closely related to representatives of the subfamily Eotrechinae than to a clade comprising Limnogonus, Neogerris, Limnometra, Tenagogerris and Tenagogonus. The two currently recognized gerrine tribes, Tachygerrini and Gerrini, were also paraphyletic, since Eurygerris was sister-group to Gigantometra, while Tachygerris was sister-group to Limnoporus + Aquarius + Gerris. Limnogonus and Neogerris were found to be strongly supported sister-taxa, and their sister-group was a clade comprising Limnometra, Tenagogerris and Tenagogonus, none of which were monophyletic. Finally, Aquarius chilensis (Berg, 1881) was sister-group to a clade comprising Aquarius amplus (Drake & Harris, 1938), A. remigis (Say, 1832) and A. remigoides (Gallant & Fairbairn, 1993), recognized as the A. remigis species group, and the entire clade was sister-group to Gerris. Based on the phylogenetic reconstruction, we outline possible diagnostic character combinations for a future revision of the Gerrinae and discuss the fossil record. While some of the relationships reinstate earlier ideas, e.g., Limnogonus and Neogerris being sister groups, many others are poorly supported and poorly diagnosed, and therefore, we retain from drawing taxonomic conclusions until data is available from the remaining genera, which can support a future generic revision of the Gerrinae. The updated checklist of species assigned to the subfamily is therefore based on the established taxonomy.


2012 ◽  
Vol 43 (3-4) ◽  
pp. 175-212 ◽  
Author(s):  
Jakob Damgaard ◽  
Felipe Ferraz Figueiredo Moreira ◽  
Masakazu Hayashi ◽  
Tom A. Weir ◽  
Herbert Zettel

The phylogenetic relationships among selected species and genera of Mesoveliidae (Insecta: Hemiptera: Heteroptera: Gerromorpha) were investigated in a parsimony analysis of 2858 bp of DNA sequence data from the genes encoding COI + II, 16S rRNA and 28S rRNA. The resulting phylogeny showed that Mesoveloidea williamsiHungerford, 1929, from the subfamily Madeoveliinae, was sister group to Mniovelia Andersen & J.T. Polhemus, 1980, from the Mesoveliinae, thus making the latter subfamily paraphyletic. The genus MesoveliaMulsant & Rey, 1852 also showed to be paraphyletic, since an undescribed Laotian relative of M. indicaHorváth, 1915 and M. ujhelyiiLundblad, 1933 resulted as sister group to PhrynoveliaHorváth, 1915; and M. amoenaUhler, 1894 was sister species to Speovelia maritimaEsaki, 1929. Whereas these relationships were poorly or moderately supported, the remaining species of Mesovelia formed two distinct and well-supported clades, one comprising M. horvathiLundblad, 1933, M. hackeriHarris & Drake, 1941, and two undescribed species from Nigeria and New Caledonia, and another comprising M. vittigeraHorváth, 1895, M. stysi J.T. Polhemus & D.A. Polhemus, 2000, M. ebbenielseniAndersen & Weir, 2004, M. furcata Mulsant & Rey, 1952, and M. mulsantiWhite, 1879. A large genetic difference was found between populations of M. vittigera from Europe and Africa on one side and populations from Australia and New Caledonia on the other. DNA sequence data from a Japanese “M. vittigera” obtained from GenBank placed the specimen as strongly supported sister group to a Danish specimen of M. furcata. Comparisons of the 28S rRNA sequence data between the two specimens revealed a single C/T transition, while comparison with a Chinese female of M. furcata revealed one A/G and one C/T transition, thus suggesting mislabelling of the Japanese specimen, or an unrecognized presence of M. furcata in Japan. Considerable genetic differentiation was found between specimens of M. horvathi from Australia, New Caledonia, New Guinea, and Laos, and between sympatric specimens of M. mulsanti from Honduras, thus supporting earlier ideas of species-complexes in these two clades. Samples of Austrovelia caledonicaMalipatil & Monteith, 1983 from New Caledonia and Mniovelia kuscheli Andersen & J.T. Polhemus, 1980 from New Zealand’s North Island also revealed considerable intraspecific divergences indicating genetic isolation among geographically separated populations on these ancient islands.


2020 ◽  
Vol 34 (2) ◽  
pp. 144 ◽  
Author(s):  
Ligia R. Benavides ◽  
Gustavo Hormiga

Mimetidae is one of the three families within Araneoidea whose members do not spin foraging webs, but are unique in displaying a complex prey-capture behaviour known as aggressive mimicry. Mimetids are distributed worldwide and are most diverse in the tropics of Central and South America. Here we provide a comprehensive phylogeny of pirate spiders (Mimetidae) based on analyses that combine morphological and multigene nucleotide sequence data. We scored 147 morphological characters for 55 mimetids and 16 outgroup taxa and combined it in a total-evidence approach with the sequence data of Benavides et al. (2017) which included two nuclear ribosomal genes, 18S rRNA and 28S rRNA, two mitochondrial ribosomal genes, 12S rRNA and 16S rRNA, the nuclear protein-encoding gene histone H3 and the mitochondrial protein-encoding gene cytochromec oxidase subunitI. We analysed the combined dataset using parsimony, maximum-likelihood and Bayesian inference methods. Our results support the monophyly of Mimetidae and of the genera Gelanor, Ero, Anansi and Australomimetus. Mimetidae is sister to Arkyidae + Tetragnathidae. Mimetus as currently circumscribed is not monophyletic under any analytical approach used, although several lineages within the genus are consistently found in our analyses. We describe, illustrate and discuss the morphological synapomorphies that support the main clades of Mimetidae. The following nomenclatural changes are proposed: Ermetus koreanus (Paik, 1967), the sole species of the genus, is transferred to Ero C.L. Koch, 1836 and thus Ermetus Ponomarev, 2008 is a junior synonym of Ero C.L. Koch, 1836 (new synonymy) and Ero koreana Paik, 1967 becomes a revalidated combination. Phobetinus sagittifer Simon, 1895, the type species of the genus, is transferred to Mimetus Hentz, 1832 and thus Phobetinus Simon, 1895 is a junior synonym of Mimetus Hentz, 1832 (new synonymy), which results in two changes: Mimetus sagittifer (Simon, 1895), new combination and Mimetus investus (Simon, 1909), new combination. Reo latro Brignoli, 1979, the type species of the genus, is transferred to Mimetus and thus Reo Brignoli, 1979 is a junior synonym of Mimetus (new synonymy), which results in the following two changes: Mimetus latro Brignoli, 1979, new combination and Mimetus eutypus Chamberlin & Ivie, 1935, revalidated combination. Arochoides integrans Mello-Leitão, 1935 is transferred to Tetragnathidae (new family placement). The type specimen of Arochoides integrans, the only species in this genus, is a subadult male of Azilia (Tetragnathidae), most likely Azilia histrio Simon, 1895. Arochoides is a junior synonym of Azilia (new synonymy). http://zoobank.org/urn:lsid:zoobank.org:pub:90F6B3DA-232B-428C-BF38-AEA8953D7685


2019 ◽  
Vol 44 (4) ◽  
pp. 930-942
Author(s):  
Geraldine A. Allen ◽  
Luc Brouillet ◽  
John C. Semple ◽  
Heidi J. Guest ◽  
Robert Underhill

Abstract—Doellingeria and Eucephalus form the earliest-diverging clade of the North American Astereae lineage. Phylogenetic analyses of both nuclear and plastid sequence data show that the Doellingeria-Eucephalus clade consists of two main subclades that differ from current circumscriptions of the two genera. Doellingeria is the sister group to E. elegans, and the Doellingeria + E. elegans subclade in turn is sister to the subclade containing all remaining species of Eucephalus. In the plastid phylogeny, the two subclades are deeply divergent, a pattern that is consistent with an ancient hybridization event involving ancestral species of the Doellingeria-Eucephalus clade and an ancestral taxon of a related North American or South American group. Divergence of the two Doellingeria-Eucephalus subclades may have occurred in association with northward migration from South American ancestors. We combine these two genera under the older of the two names, Doellingeria, and propose 12 new combinations (10 species and two varieties) for all species of Eucephalus.


Sign in / Sign up

Export Citation Format

Share Document