Search results for "crust"
showing 10 items of 599 documents
Arable-weed flora and its pollen representation: A case study from the eastern part of France
2007
International audience; Local pollen deposition in human-influenced vegetation types is studied with the aim of establishing the relationship between arable-weed vegetation and its pollen representation as an aid in interpreting human presence and impact on vegetation from pollen assemblages. The study area is located in the Franche-Comté region, eastern part of France. The presence of plants within 100 m2 plots and their pollen representation in moss samples within the same plots was recorded from different crops and annual fallows. Patterns in the vegetation and pollen assemblages were investigated separately using principal coordinate analysis (PCoA). Procrustean co-inertia analysis (PCI…
Variation in the immune state of Gammarus pulex (Crustacea, Amphipoda) according to temperature: are extreme temperatures a stress?
2017
9 pages; International audience; Temperature is known to impact host-parasite interactions in various ways. Such effects are often regarded as the consequence of the increased metabolism of parasites with increasing temperature. However, the effect of temperature on hosts' immune system could also be a determinant. Here we assessed the influence of temperature on the immunocompetence of the crustacean amphipod Gammarus pulex. Amphipods play a key ecological role in freshwater ecosystems that can be altered by several parasites. We investigated the consequences of three weeks of acclimatization at four temperatures (from 9 °C to 17 °C) on different immunological parameters. Temperature influ…
The legacy of a vanished sea: a high level of diversification within a European freshwater amphipod species complex driven by 15 My of Paratethys reg…
2016
16 pages; International audience; The formation of continental Europe in the Neogene was due to the regression of the Tethys Ocean and of the Paratethys Sea. The dynamic geology of the area and repetitious transitions between marine and freshwater conditions presented opportunities for the colonization of newly emerging hydrological networks and diversification of aquatic biota. Implementing mitochondrial and nuclear markers in conjunction with a large-scale sampling strategy, we investigated the impact of this spatiotemporal framework on the evolutionary history of a freshwater crustacean morphospecies. The Gammarus balcanicus species complex is widely distributed in the area previously oc…
Líquenes y hongos liquenícolas de la Serranía de Ronda (Málaga-Cádiz), sur de España
2017
As a result of a field trip organised by the Spanish Lichen Society in Serranía de Ronda, south Spain, a catalogue of 360 taxa is presented (336 lichens, 24 lichenicolous fungi). The list includes three new records for the Iberian Peninsula: Arthonia paretinaria, Micarea myriocarpa and Niesslia keissleri, 51new ones for the Autonomous Andalusian Community, and three and 81 new ones for the province of Cádiz and of Málaga, respectively. After these results, the total updated number of the province of Málaga rises to 556 lichens and lichenicolous fungi. The best represented lichen genus is Cladonia (18) with the most species, unlike Lecanora (15), Pertusaria (12), Physconia (12) and Collema (…
Jumping on the Edge—First Evidence for a 2 × 6-meric Hemocyanin in Springtails
2019
Hemocyanins are respiratory dioxygen carrier proteins found in many arthropods including ancient terrestrial species such as spiders and scorpions as well as marine horseshoe crabs. As hemocyanins are highly conserved in this lineage, it is possible to observe an evolutionary descent through its subunits and their overall structure. Unfortunately, little is known about the structure and function of hexapod hemocyanins. Using recent springtail taxa (Collembola) as models for basal hexapods, and the help of electron microscopy, light scattering, SDS PAGE, and Western blot, we could demonstrate for the first time the presence of 2 × 6-meric hemocyanins in the hemolymph of hexapods. The quatern…
Kineococcus vitellinus sp. nov., Kineococcus indalonis sp. nov. and Kineococcus siccus sp. nov., isolated nearby the Tabernas desert (Almería, Spain)
2020
This article belongs to the Section Environmental Microbiology.
Molecular and morphological diversity ofTrebouxiamicroalgae in sphaerothallioidCircinariaspp. lichens1
2018
Three vagrant (Circinaria hispida, Circinaria gyrosa, and Circinaria sp. 'paramerae') and one crustose (semi-vagrant, Circinaria sp. 'oromediterranea') lichens growing in very continental areas in the Iberian Peninsula were selected to study the phycobiont diversity. Mycobiont identification was checked using nrITS DNA barcoding: Circinaria sp. 'oromediterranea' and Circinaria sp. 'paramerae' formed a new clade. Phycobiont diversity was analyzed in 50 thalli of Circinaria spp. using nrITS DNA and LSU rDNA, with microalgae coexistence being found in all the species analyzed by Sanger sequencing. The survey of phycobiont diversity showed up to four different Trebouxia spp. as the primary phyc…
Additive effects of temperature and infection with an acanthocephalan parasite on the shredding activity of Gammarus fossarum (Crustacea: Amphipoda):…
2017
10 pages; International audience; Climate change can have critical impacts on the ecological role of keystone species, leading to subsequent alterations within ecosystems. The consequences of climate change may be best predicted by understanding its interaction with the cumulative effects of other stressors, although this approach is rarely adopted. However, whether this interaction is additive or interactive can hardly be predicted from studies examining a single factor at a time. In particular, biotic interactions are known to induce modifications in the functional role of many species. Here, we explored the effect of temperature on leaf consumption by a keystone freshwater shredder, the …
Multiple-stressor effects of warming and acidification on the embryonic development of an estuarine fiddler crab
2021
Made available in DSpace on 2021-06-25T10:56:04Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-06-05 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Predicted effects of anthropogenic climate change on estuarine and coastal organisms are complex, and early life history stages of calcified ectotherms are amongst the most sensitive groups. Despite the importance of understanding their vulnerability, we lack information on the effects of multiple stressors on the embryonic development of estuarine and burrowing organisms, mainly mangrove-associated species. Here, we determined the combined effects of elevated temperature and decreased pH on the embryonic development of th…
Différenciation morphologique et génétique des populations de douroucoulis (Aotus infulatus, Primates, Platyrhiniens, Cebidae) provenant des rives dr…
2007
11 pages; La morphologie crânienne de 28 spécimens de douroucoulis (genre Aotus), provenant du Bassin amazonien, a été étudiée à l'aide de méthodes de morphométrie géométrique en trois dimensions. De nouveaux résultats concernant la distinction morphologique de populations de l'espèce Aotus infulatus, réparties de part et d'autre du rio Tocantins, sont proposés. Ces résultats morphologiques concordent avec la distinction génétique de ces populations publiée par Schneider – et Sampaio –, et indiquent probablement de récents et rapides changements évolutifs au sein de cette espèce. Les résultats de cette étude ont une application taxinomique, mais pourraient également ouvrir de nouvelles pers…