The population of Carassius gibelio (Bloch, 1782) and its parasites in Madatapa Lake (South Georgia)

Gibel carp is a very successful invasive fish species in the waters of Georgian inland and the only fish species in Lake Madatapa. However, almost nothing is known about its biology and morpho-ecological peculiarities at the national level and even the distribution data is not documented. For the first time, we studied the population characteristics of gibel carp in Lake Madatapa (South Georgia) with the aim to reveal the extent of its morphological variability, sex ratio, length-weight relationship and its parasitic community. We showed that the gibel carp population in Madatapa Lake has typical morphological characteristics. The sex ratio is significantly female biased (1/1.8) and the length-weight relationship is within the published margins. The gibel carp population is under the heavy parasitic load, but only two parasitic species (one cestoda and the other digenean species) affect the fishes. Within the framework of the obtained results, we discussed future research needs concerning the gibel carp in the lake

Comparison of Earthworm (Lumbricidae) and Oribatid Mite (Acari, Oribatida) Communities in Natural and Urban Ecosystems

This study investigates earthworm and oribatid mite communities in urban, semi-natural and natural ecosystems of Tbilisi (Georgia). Ten species of earthworms and 100 species of oribatid mites were registered in 45 soil samples. Two species of oribatid mites, Microzetes auxilaris Grandjean, 1936 and Multioppia laniseta Moritz, 1966, are new for the Caucasian fauna. We hypothesized that species number and abundance of invertebrate animals tend to decrease from natural to urban ecosystems. The hypothesis was supported only partially. Number of species of oribatid mites and earthworms decreased together with increase of urbanization, whereas abundance showed no significant changes due to high density of stress tolerant and ubiquitous species in urban sites. Accordingly, species abundance is considered to have minor indicatory value. Our studies support ecological “time-hypothesis” in a way that older (natural) sites were presented with more diverse fauna than recent (urban) ones. Statistical analyses showed that studied ecosystems should be grouped in two rather than three categories: in urban and natural ones.В статье предоставлены результаты исследования сообществ дождевых червей и панцирных клещей в урбанизированных, полуприродных и природных экосистемах г. Тбилиси (Грузия). В 45 почвенных пробах были найдены 10 видов дождевых червей и 100 видов панцирных клещей. Два вида клещей Microzetes auxilaris Grandjean, 1936 и Multioppia laniseta Moritz, 1966 являются новымы для фауны Кавказа. Мы предположили, что количество и плотность населения безпозвоночных должны уменьшаться от природных к урбанизированным экосистемам. Наша гипотеза подтвердилась частично. Количество видов дождевых червей и панцирных клещей сократилось с увеличением степени урбанизированности среды, тогда, как плотность населения существенно не менялась из-за высокой плотности отдельных убиквистовых и толерантных к стрессам видов. Соответственно считаем, что плотность населения не имеет большого индикационного значения. Наши результаты подтверждают экологическую «гипотезу времени» тем, что более старые (природные) участки были представлены более разнообразной фауной, чем более новые (урбанизированные). Статистический анализ показал, что изученные экосистемы должны быть сгруппированны по двум, а не по трем категориям: по природным и урбанизированным

The impact of insect herbivory on biogeochemical cycling in broadleaved forests varies with temperature

Herbivorous insects alter biogeochemical cycling within forests, but the magnitude of these impacts, their global variation, and drivers of this variation remain poorly understood. To address this knowledge gap and help improve biogeochemical models, we established a global network of 74 plots within 40 mature, undisturbed broadleaved forests. We analyzed freshly senesced and green leaves for carbon, nitrogen, phosphorus and silica concentrations, foliar production and herbivory, and stand-level nutrient fluxes. We show more nutrient release by insect herbivores at non-outbreak levels in tropical forests than temperate and boreal forests, that these fluxes increase strongly with mean annual temperature, and that they exceed atmospheric deposition inputs in some localities. Thus, background levels of insect herbivory are sufficiently large to both alter ecosystem element cycling and influence terrestrial carbon cycling. Further, climate can affect interactions between natural populations of plants and herbivores with important consequences for global biogeochemical cycles across broadleaved forests

A global agenda for advancing freshwater biodiversity research

This manuscript is a contribution of the Alliance for Freshwater Life (www.allianceforfreshwaterlife.org). We thank Nick Bond, Lisa Bossenbroek, Lekima Copeland, Dean Jacobsen, Maria Cecilia Londo?o, David Lopez, Jaime Ricardo Garcia Marquez, Ketlhatlogile Mosepele, Nunia Thomas-Moko, Qiwei Wei and the authors of Living Waters: A Research Agenda for the Biodiversity of Inland and Coastal Waters for their contributions. We also thank Peter Thrall, Ian Harrison and two anonymous referees for their valuable comments that helped improve the manuscript. Open access funding enabled and organised by Projekt DEAL

Integrative phylogenetic, phylogeographic and morphological characterisation of the Unio crassus species complex reveals cryptic diversity with important conservation implications

The global decline of freshwater mussels and their crucial ecological services highlight the need to understand their phylogeny, phylogeography and patterns of genetic diversity to guide conservation efforts. Such knowledge is urgently needed for Unio crassus, a highly imperilled species originally widespread throughout Europe and southwest Asia. Recent studies have resurrected several species from synonymy based on mitochondrial data, revealing U. crassus to be a complex of cryptic species. To address long-standing taxonomic uncertainties hindering effective conservation, we integrate morphometric, phylogenetic, and phylogeographic analyses to examine species diversity within the U. crassus complex across its entire range. Phylogenetic analyses were performed using cytochrome c oxidase subunit I (815 specimens from 182 populations) and, for selected specimens, whole mitogenome sequences and Anchored Hybrid Enrichment (AHE) data on ∼600 nuclear loci. Mito-nuclear discordance was detected, consistent with mitochondrial DNA gene flow between some species during the Pliocene and Pleistocene. Fossil-calibrated phylogenies based on AHE data support a Mediterranean origin for the U. crassus complex in the Early Miocene. The results of our integrative approach support 12 species in the group: the previously recognised Unio bruguierianus, Unio carneus, Unio crassus, Unio damascensis, Unio ionicus, Unio sesirmensis, and Unio tumidiformis, and the reinstatement of five nominal taxa: Unio desectus stat. rev., Unio gontierii stat. rev., Unio mardinensis stat. rev., Unio nanus stat. rev., and Unio vicarius stat. rev. Morphometric analyses of shell contours reveal important morphospace overlaps among these species, highlighting cryptic, but geographically structured, diversity. The distribution, taxonomy, phylogeography, and conservation of each species are succinctly described

The impact of insect herbivory on biogeochemical cycling in broadleaved forests varies with temperature

Herbivorous insects alter biogeochemical cycling within forests, but the magnitude of these impacts, their global variation, and drivers of this variation remain poorly understood. To address this knowledge gap and help improve biogeochemical models, we established a global network of 74 plots within 40 mature, undisturbed broadleaved forests. We analyzed freshly senesced and green leaves for carbon, nitrogen, phosphorus and silica concentrations, foliar production and herbivory, and stand-level nutrient fluxes. We show more nutrient release by insect herbivores at non-outbreak levels in tropical forests than temperate and boreal forests, that these fluxes increase strongly with mean annual temperature, and that they exceed atmospheric deposition inputs in some localities. Thus, background levels of insect herbivory are sufficiently large to both alter ecosystem element cycling and influence terrestrial carbon cycling. Further, climate can affect interactions between natural populations of plants and herbivores with important consequences for global biogeochemical cycles across broadleaved forests

Elevational abundance data for oribatid mite species from a western Lesser Caucasus (Georgia)

The data set represents oribatid mite species abundance data for Sairme gorge (Lesser Caucasus, Georgia). In 2013, mites were sampled from 600 m a.s.l. up to 2200 m with constant distance (200 m) between elevational bands (9 in total). At each elevation 3 replicate were made with 50 m minimum distances between replicates. Data set also contains some environmental variables (in a second sheet) such as pH, slope etc, and calculated diversity indexes. The data was used in an article published in Experimental and Applied Acarology (DOI 10.1007/s10493-015-9893-4)

Elevational abundance data for oribatid mite species from a western Lesser Caucasus (Georgia)

The data set represents oribatid mite species abundance data for Sairme gorge (Lesser Caucasus, Georgia). In 2013, mites were sampled from 600 m a.s.l. up to 2200 m with constant distance (200 m) between elevational bands (9 in total). At each elevation 3 replicate were made with 50 m minimum distances between replicates. Data set also contains some environmental variables (in a second sheet) such as pH, slope etc, and calculated diversity indexes. The data was used in an article published in Experimental and Applied Acarology (DOI 10.1007/s10493-015-9893-4).THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

The consistent criteria of hypotheses

In this paper we define the consistent criteria of hypotheses such as the probability of any kind of errors is zero for given criteria. We prove necessary and sufficient conditions for the existence of such criteria