Search results for "Zoology"
showing 10 items of 4160 documents
Resurrection of Pomphorhynchus tereticollis (Rudolphi, 1809) (Acanthocephala: Pomphorhynchidae) based on new morphological and molecular data
2011
Abstract Pomphorhynchus tereticollis (Rudolphi, 1809) is here redescribed on the basis of Rudolphi’s material, deposited in the Museum für Naturkunde Berlin, and on acanthocephalans recently collected from the type host Platichthys flessus (L.) and the region embodying the type locality. Out of the paratypes of P. tereticollis, the lectotype and paralectotypes have been designated. Their morphology fits well with that of newly collected material of P. tereticollis dissected from the type fish host from the Baltic coast near Stralsund. The resurrection of P. tereticollis, previously considered a synonym of Pomphorhynchus laevis (Zoega in Müller, 1779), is supported by several morphological f…
Solving a Bloody Mess: B-Vitamin Independent Metabolic Convergence among Gammaproteobacterial Obligate Endosymbionts from Blood-Feeding Arthropods an…
2015
Endosymbiosis is a common phenomenon in nature, especially between bacteria and insects, whose typically unbalanced diets are usually complemented by their obligate endosymbionts. While much interest and focus has been directed toward phloem-feeders like aphids and mealybugs, blood-feeders such as the Lone star tick (Amblyomma americanum), Glossina flies, and the human body louse (Pediculus humanus corporis) depend on obligate endosymbionts which complement their B-vitamin-deficient diets, and thus are required for growth and survival. Glossiphoniid leeches have also been found to harbor distinct endosymbionts housed in specialized organs. Here, we present the genome of the bacterial endosy…
Gender-related variations in hemolymph parameters of Carabus lefebvrei (Coleoptera: Carabidae): HPLC analysis and phenoloxidase activity
2017
We characterized the enzymatic activity of basal and total phenoloxidase and HLPC and SDS- PAGE profiles in hemolymph of Carabus lefebvrei males and females at different reproductive status. The phenoloxidase activity was activated by trypsin and inhibited by phenoloxidase activity specific inhibitor phenylthiourea. Our results demonstrated that both in males and females, there were no significant differences in the basal phenoloxidase activity between reproductive and virgin beetles, while the total phenoloxidase activity increased significantly in virgin specimens. Thus, resources seem to be invested to increase the humoral response in pre-reproductive phase forming a barrier against path…
Temperature effects explain continental scale distribution of cyanobacterial toxins
2018
Insight into how environmental change determines the production and distribution of cyanobacterial toxins is necessary for risk assessment. Management guidelines currently focus on hepatotoxins (microcystins). Increasing attention is given to other classes, such as neurotoxins (e.g., anatoxin-a) and cytotoxins (e.g., cylindrospermopsin) due to their potency. Most studies examine the relationship between individual toxin variants and environmental factors, such as nutrients, temperature and light. In summer 2015, we collected samples across Europe to investigate the effect of nutrient and temperature gradients on the variability of toxin production at a continental scale. Direct and indirect…
Difficulty of getting accurate and precise estimates of population size: The case of the Siberian flying squirrel in Finland
2008
Accurate estimates of population size and distribution are a prerequisite for effective management of populations, but for most species a reliable estimation of the absolute population size is very difficult. In 1998, the Finnish Ministry of Environment set up a working group to plan a national-level survey for estimation and monitoring of the population size of Siberian flying squirrel (Pteromys volans). In 2006, the population size was reported to be 143 000 females. However, evaluation of the magnitude of possible biases was not attempted. Our aim was to test the population size estimate by conducting a resampling study with the methods of the national survey on an eartagged population o…
Vendace (Coregonus albula) Disperse Their Eggs Widely during Spawning
2021
Depending on their reproductive strategy, different fish species either aggregate or disperse eggs and larvae in their reproductive habitat. Because yolk-sac larvae of vendace (Coregonus albula) disperse widely across the littoral and pelagic zones of boreal lakes, it is unclear where the exact spawning and egg incubation locations are. Vendace egg and larvae densities were studied in Lake Southern Konnevesi to clarify its spawning strategy. In autumn 2019, 1–2 weeks prior to spawning, 500 egg samplers were installed in five depth zones in 20 sampling plots. Fertilized eggs were found in 18 plots. The mean density of eggs was 74 eggs m–2 and the mean fertilization rate 85%. During spawning,…
Genome-wide mapping of signatures of selection using a high-density array identified candidate genes for growth traits and local adaptation in chicke…
2023
Abstract Background Availability of single nucleotide polymorphism (SNP) genotyping arrays and progress in statistical analyses have allowed the identification of genomic regions and genes under selection in chicken. In this study, SNP data from the 600 K Affymetrix chicken array were used to detect signatures of selection in 23 local Italian chicken populations. The populations were categorized into four groups for comparative analysis based on live weight (heavy vs light) and geographical area (Northern vs Southern Italy). Putative signatures of selection were investigated by combining three extended haplotype homozygosity (EHH) statistical approaches to quantify excess of haplotype homoz…
Biology of the sauropod dinosaurs: the evolution of gigantism
2010
The herbivorous sauropod dinosaurs of the Jurassic and Cretaceous periods were the largest terrestrial animals ever, surpassing the largest herbivorous mammals by an order of magnitude in body mass. Several evolutionary lineages among Sauropoda produced giants with body masses in excess of 50 metric tonnes by conservative estimates. With body mass increase driven by the selective advantages of large body size, animal lineages will increase in body size until they reach the limit determined by the interplay of bauplan, biology, and resource availability. There is no evidence, however, that resource availability and global physicochemical parameters were different enough in the Mesozoic to ha…
Hans Šlešs un viņa kolekcija
2021
Virtuālajā izstādē, kas veltīta malakologam Hansam Šlešam, Latvijas Universitātes Muzeja Zooloģijas kolekcijas piedāvā iespēju uzzināt par pētnieka biogrāfiju, publikācijām, zinātniskajiem sasniegumiem un Zooloģijas muzejam dāvināto gliemju čaulu paraugu kolekciju.
Risk assessment of information on the subcombination Bt11 × 1507 × GA21, related to the application of Syngenta (EFSA‐GMO‐DE‐2011‐99) for authorisati…
2017
Efsa Panel On Genetically Modified Organisms (gmo)StatementRequestor: European CommissionQuestion number: EFSA-Q-2016-00730; The EFSA Panel on Genetically Modified Organisms (GMO) has previously assessed the single events Bt11, MIR162, MIR604 and GA21 as well as different stacked events corresponding to combinations of these events. These maize events were found to be as safe as their conventional counterparts and other appropriate comparators with respect to potential effects on human and animal health and the environment. In its assessment of the four-event maize stack Bt11 9 MIR162 9 MIR604 9 GA21, the GMO Panel also assessed all the subcombinations of these events not previously assesse…