Search results for "SYSTEMATICS"
showing 10 items of 6702 documents
Solving the Puzzle of Taxonomic Position of the Petroleum Fly by Resurrection of Diasemocera Bezzi from Psilopa Fallén (Diptera: Ephydridae) with Pro…
2018
Diasemocera Bezzi, 1895 (Type species: Psilopa nigrotaeniata Bezzi, 1895 [= Psilopa roederi Girschner, 1889]) is resurrected from synonymy with Psilopa and the following four new synonyms of Diasemocera are proposed: Domina Hutton (Type species: Domina metallica Hutton), Discocerinella Mercier (Type species: Discocerinella omonvillea Mercier, 1927 [= Notiphila pulicaria Haliday, 1839]), Trimerinoides Cresson (Type species: Trimerina adfinis Cresson) and Helaeomyia Cresson, 1941 (Type species: Psilopa petrolei Coquillett). Diasemocera is placed close to the genus Trimerina and it differs from the highly specialized Psilopa and related genera by the number of pseudotracheae (6–7), vestiture o…
Underwater noise from boats: Measurement of its influence on the behaviour and biochemistry of the common prawn (Palaemon serratus, Pennant 1777)
2016
Abstract This study examined the effects of recorded boat noises on the behaviour and biochemistry of the common prawn ( Palaemon serratus ) in laboratory settings. The experiment was carried out in a tank equipped with a video-recording system using six groups (three control and three tested) of eight common prawns (48 animals in total). After habituation for 1 h, the behaviour of the prawns was monitored for 1 h. During the last 30 min, the animals in the test groups were exposed to noise resembling a marine area with high anthropogenic acoustic pollution. The exposure to noise produced significant changes in locomotor patterns, presence inside or outside a shelter, total protein concentr…
DNA polymorphism at the FRIGIDA gene in Arabidopsis thaliana : extensive nonsynonymous variation is consistent with local selection for flowering time
2002
FRIGIDA (FRI) is a major gene involved in the regulation of flowering time in Arabidopsis thaliana. Nucleotide variation at this gene was investigated by sequencing 25 field ecotypes collected from western Europe. Genetic diversity at FRI was characterized by a high number of haplotypes and an excess of low-frequency polymorphisms. A large excess of intraspecific nonsynonymous variation associated with low synonymous variation was detected along the first exon in the FRI gene. In contrast, no excess of nonsynonymous divergence was detected between A. thaliana and A. lyrata. The Tajima and McDonald and Kreitman tests, however, suggested that this gene has evolved in a nonneutral fashion. Non…
Nucleotide Variability at the Acetyl Coenzyme A Carboxylase Gene and the Signature of Herbicide Selection in the Grass Weed Alopecurus myosuroides (H…
2004
Acetyl coenzyme A carboxylase (ACCase) is the target of highly effective herbicides. We investigated the nucleotide variability of the ACCase gene in a sample of 18 black-grass (Alopecurus myosuroides [Huds.]) populations to search for the signature of herbicide selection. Sequencing 3,396 bp encompassing ACCase herbicide-binding domain in 86 individuals revealed 92 polymorphisms, which formed 72 haplotypes. The ratio of nonsynonymous versus synonymous substitutions was very low, in agreement with ACCase being a vital metabolic enzyme. Within black grass, most nonsynonymous substitutions were related to resistance to ACCase-inhibiting herbicides. Differentiation between populations was stro…
Can Deliberately Incomplete Gene Sample Augmentation Improve a Phylogeny Estimate for the Advanced Moths and Butterflies (Hexapoda: Lepidoptera)?
2011
Abstract This paper addresses the question of whether one can economically improve the robustness of a molecular phylogeny estimate by increasing gene sampling in only a subset of taxa, without having the analysis invalidated by artifacts arising from large blocks of missing data. Our case study stems from an ongoing effort to resolve poorly understood deeper relationships in the large clade Ditrysia ( > 150,000 species) of the insect order Lepidoptera (butterflies and moths). Seeking to remedy the overall weak support for deeper divergences in an initial study based on five nuclear genes (6.6 kb) in 123 exemplars, we nearly tripled the total gene sample (to 26 genes, 18.4 kb) but only in a…
A new flatworm species of Temnocephala (Rhabdocoela, Temnocephalidae) ectosymbiont on the freshwater crab Valdivia serrata (Decapoda, Trichodactylida…
2020
A new species of temnocephalan is described from the branchial chambers ofValdivia serratain Colombia asTemnocephala ivandarioisp. nov.The most distinctive characters of the new species are in the cirrus and the epidermal ‘excretory’ syncytial plates. In the present study, the terminology to describe the cirrus of species ofTemnocephalais updated. Comparison between the shape of the cirrus of the temnocephalans associated with trichodactylid crabs is also provided.
Numerical response of predators to large variations of grassland vole abundance and long‐term community changes
2020
Abstract Voles can reach high densities with multiannual population fluctuations of large amplitude, and they are at the base of predator communities in Northern Eurasia and Northern America. This status places them at the heart of management conflicts wherein crop protection and health concerns are often raised against conservation issues. Here, a 20‐year survey describes the effects of large variations in grassland vole populations on the densities and the daily theoretical food intakes (TFI) of vole predators based on roadside counts. Our results show how the predator community responded to prey variations of large amplitude and how it reorganized with the increase in a dominant predator…
The effects of absolute and relative nutrient concentrations (N/P) on phytoplankton in a subtropical reservoir
2020
Abstract The elemental composition of phytoplankton is a critical factor for primary production and nutrient recycling. The increase anthropogenic nutrient input into freshwater ecosystems is affecting phytoplankton assemblage structure and its stoichiometry. Reservoirs of South China generally show low level of phosphate and it is not clear how phytoplankton can grow and occasionally bloom in such conditions. Therefore, an indoor experiment was conducted to investigate the response of natural phytoplankton communities to 25 levels of supplied nitrogen to phosphorus ratios (N/P), arising from the combination of 5 levels of N and P. Our aim was to check the effects of absolute and relative N…
Grazing decreases N partitioning among coexisting plant species
2017
Herbivores play a key role in shaping ecosystem structure and functions by influencing plant and microbial community composition and nutrient cycling. This study investigated the long‐term effects of herbivores on plant resource acquisition. We explored differences in the natural δ15N signatures in plant, microbial and soil N pools, and examined mycorrhizal colonization in two tundra sites that have been either lightly or heavily grazed by reindeer for more than 50 years. The study examined changes in nutrient acquisition in five common tundra plants with contrasting traits and mycorrhiza status; the mycorrhizal dwarf shrubs, Betula nana, Vaccinium myrtillus and Empetrum hermaphroditum; a m…
Atlas of Finnish bats
2019
This atlas is based on information in museum collections, literature, databases and unpublished data. In the last 150 years, the number of bat species in Finland increased from six to thirteen. Of these, five are common and regularly breeding (Eptesicus nilssonii, Myotis brandtii, Myotis daubentonii, Myotis mystacinus, Plecotus auritus), and eight rare (Eptesicus serotinus, Myotis dasycneme, Myotis nattereri, Nyctalus noctula, Pipistrellus nathusii, Pipistrellus pipistrellus, Pipistrellus pygmaeus, Vespertilio murinus), of which breeding of two (M. nattereri, P. nathusii) have been confirmed. The total number of records in the study is 11 234, of which 9717 are identified to species. The re…