Decomposition and insect colonization patterns of pig cadavers lying on forest soil and suspended above ground.

Hanging is one of the most common methods of suicide, and, although it is known that decomposition and patterns of insect fauna colonization of hanging cadavers differ from those of cadavers decomposing on the ground, these differences have only been sparsely studied in Europe so far. We studied the decomposition and insect colonization patterns of ten pig (Sus scrofa domestica) carcasses in a spruce forest near Neuchâtel, Switzerland, over a 32-day period in summer 2013 (July 1st - August 2nd). Five pig carcasses were suspended horizontally in metal cages one meter above the ground and five carcasses were placed directly on the ground. The species occurrence and abundance of Coleoptera and Diptera recovered from passive pitfall traps and collected manually on the carcasses were recorded. Indicator species of decomposition stages and suspended vs. ground cadavers were identified by Indicator Value (IndVal) analysis. The ground carcasses decomposed significantly faster than the suspended carcasses. Coleoptera and Diptera communities differed significantly over time, between treatment, and the treatment effect varied over time. Diptera were evenly distributed among the two treatments. Coleoptera were more abundant and less differentiated on the ground carcasses and represent better indicators of cadavers decomposing on the soil as well as decomposition stages. Our results suggest possible applications such as evaluating if a hanged cadaver has been dropped to the ground, or inversely if a cadaver first lying on the soil has later been hung to fake a suicide. However differences among studies suggest possible effects of meso-climate determined by habitat which should be explored further.

Ground beetle assemblages across a habitat gradient in a stream watershed during 16 years of observation.

Most studies on riverine ground beetle assemblages last 1-2 years, and studies on carabids from lowland stream ecosystems are rare. In 1999, a 16-year study was launched to gain insight into the structure and diversity of carabid assemblages in a cross-section of four habitats located beside a 5 m wide stream: Meadow (wet meadow), Clumps (meadow scattered with birch and willow clumps farther from the river), Birch (birch stand), and Pine (pine stand located the farthest from the stream). The total number of 14, 216 individuals representing 118 carabid species were collected. Eleven functional carabid groups have been analysed. Principal response curve analysis showed significant differences existing during the whole study period among carabid assemblages from the four habitats. Generalised Linear Mixed Models analysis revealed a dependence of Chao2 estimator performance on temperature and ground water level, whereas life traits of carabids depended solely on the latter factor, affecting species composition (i.e., proportions of autumn and spring breeders, large and small zoophages, hemizoophages, forest, generalists and open area species, wingless species, hygrophilous, mesophilous and xerophilous species). The lower the ground water level, the higher was the proportion of late-successional species. Both Chao2 value and the proportion of late-successional species were growing with the increasing distance from the stream, peaking in the Pine habitat. Early-successional fauna dominated in streamside assemblages. IndVal analysis identified 1-9 characteristic species for each habitat type, mostly non-recurrent during the study period. Thus, species composition of riverine carabid assemblages should be studied for longer periods than 1-2 years to avoid accidental observations.

Cost-effectiveness of using small vertebrates as indicators of disturbance.

In species-rich tropical forests, effective biodiversity management demands measures of progress, yet budgetary limitations typically constrain capacity of decision makers to assess response of biological communities to habitat change. One approach is to identify ecological-disturbance indicator species (EDIS) whose monitoring is also monetarily cost-effective. These species can be identified by determining individual species' responses to disturbance across a gradient; however, such responses may be confounded by factors other than disturbance. For example, in mountain environments the effects of anthropogenic habitat alteration are commonly confounded by elevation. EDIS have been identified with the indicator value (IndVal) metric, but there are weaknesses in the application of this approach in complex montane systems. We surveyed birds, small mammals, bats, and leaf-litter lizards in differentially disturbed cloud forest of the Ecuadorian Andes. We then incorporated elevation in generalized linear (mixed) models (GL(M)M) to screen for EDIS in the data set. Finally, we used rarefaction of species accumulation data to compare relative monetary costs of identifying and monitoring EDIS at equal sampling effort, based on species richness. Our GL(M)M generated greater numbers of EDIS but fewer characteristic species relative to IndVal. In absolute terms birds were the most cost-effective of the 4 taxa surveyed. We found one low-cost bird EDIS. In terms of the number of indicators generated as a proportion of species richness, EDIS of small mammals were the most cost-effective. Our approach has the potential to be a useful tool for facilitating more sustainable management of Andean forest systems.

Influence of hydraulic clam dredging and seasonal environmental changes on macro-benthic communities in the Southern Adriatic (Central Mediterranean Sea).

Macro-benthic communities on the shallowest soft bottoms are impacted by hydraulic dredgers used for the harvesting of the striped venus clam (Chamelea gallina). Changes in macro-benthic assemblages were analysed across four areas in the Southern Adriatic Sea (Central Mediterranean Sea) during the winter and summer 2022 (low and high fishing pressures, respectively). Two sampling surveys were carried out collecting abundance data (N/100m2) of 69 species. Diversity indices (Shannon-Weiner and Equitability) were calculated and differences between seasons and areas were tested using non-parametric tests. Changes in the assemblage and feeding habits were explored by adopting permutational multivariate analysis of variance on 34 species. Moreover, environmental conditions of all areas in the two seasons were characterized by a set of 8 variables. Seasonal changes in diversity were only detected for the Shannon-Weiner index, with values significantly higher in winter than summer. Macro-benthic assemblages differed between the two seasons, and the winter assemblages were well-distinct in each area. In contrast, a high overlap was shown in the summer assemblages of the four areas. Changes in feeding habits showed an increase in filter feeding polychaetes and opportunistic/scavenger species during the summer. Temperature, Salinity and primary production were positively correlated to summer stations indicating potential thermic stress on the assemblages. The results provide information on the benthic community impacted by dredge disturbance and seasonal changes driven by environmental conditions, stressing the need to integrate these aspects in assessments on the health status of marine ecosystems required by European directives and fishery management plans.

Tangled in a Web: Management Type and Vegetation Shape the Occurrence of Web-Building Spiders in Protected Areas.

Land management of parks and vegetation complexity can affect arthropod diversity and subsequently alter trophic interactions between predators and their prey. In this study, we examined spiders in five parks with varying management histories and intensities to determine whether certain spider species were associated with particular plants. We also determined whether web architecture influenced spider occurrence. Our results showed that humpbacked orb-weavers (Eustala anastera) were associated with an invasive plant, Chinese privet (Ligustrum sinense). This study revealed how invasive plants can potentially influence certain spider communities, as evidenced by this native spider species only occurring on invasive plants. Knowing more about spider populations-including species makeup and plants they populate-will give insights into how spider populations are dealing with various ecosystem changes. While we did not assess the effect of invasive plants on the behavior of spiders, it is possible that invasive species may not always be harmful to ecosystems; in the case of spiders, invasive plants may serve as a useful environment to live in. More studies are needed to ascertain whether invasive plants can have adverse effects on spider ecology in the long term.

Assessment of benthic macroinvertebrates as potential bioindicators of anthropogenic disturbance in southeast Bangladesh coast.

Many human activities can greatly influence and alter the health of aquatic ecosystems. In this regard, the quantitative analysis of macroinvertebrates and their relationships with ecological variables is an effective method in environmental monitoring programs. Here, we used the benthic macroinvertebrate community as bioindicators for assessing anthropogenic impacts on coastal waters in southeast Bangladesh. Sediment samples were collected seasonally from three different sites influenced either by mangrove forests, aquaculture activity or sewage input. The indicator value index (IndVal) analysis revealed 23 species of benthic macroinvertebrates as potential bioindicators namely Enigmonia aenigmatica, Mactra chinensis and Pharella javanica of the class Bivalvia; Tubifex tubifex of the class Clitellata; Lithopoma brevispina, Bullia vittata, Pomacea maculata and Umbonium vestiarium of the class Gastropoda; Gammarus roeselii of the class Malacostraca; and Amphicteis gunneri, Amphitrite ornata, Aricidea simplex, Cirratulus cirratus, Heterospio catalinensis, Hypereteone foliosa, Lopadorrhynchus henseni, Neanthes chingrighattensis, Micronephthys oligobranchia, Nephtys hombergii, Nereis jacksoni, Nereis zonata, Polyodontes maxillosus and Stygocapitella subterranean of the class Polychaeta. Their composition across three sites varied significantly (P < 0.05) due to influence of environmental conditions as inferred from redundancy analysis. Polychaeta, Gastropoda and Malacostraca were susceptible to sewage input, while Bivalvia and Clitellata were susceptible to aquaculture effluent. The results of this baseline study suggest that the identified benthic macroinvertebrate species can potentially be used to monitor anthropogenic disturbances in the marine environment.

Proteomic similarity of the Littorinid snails in the evolutionary context.

BACKGROUND: The introduction of DNA-based molecular markers made a revolution in biological systematics. However, in cases of very recent divergence events, the neutral divergence may be too slow, and the analysis of adaptive part of the genome is more informative to reconstruct the recent evolutionary history of young species. The advantage of proteomics is its ability to reflect the biochemical machinery of life. It may help both to identify rapidly evolving genes and to interpret their functions. METHODS: Here we applied a comparative gel-based proteomic analysis to several species from the gastropod family Littorinidae. Proteomes were clustered to assess differences related to species, geographic location, sex and body part, using data on presence/absence of proteins in samples and data on protein occurrence frequency in samples of different species. Cluster support was assessed using multiscale bootstrap resampling and the stability of clustering-using cluster-wise index of cluster stability. Taxon-specific protein markers were derived using IndVal method. Proteomic trees were compared to consensus phylogenetic tree (based on neutral genetic markers) using estimates of the Robinson-Foulds distance, the Fowlkes-Mallows index and cophenetic correlation. RESULTS: Overall, the DNA-based phylogenetic tree and the proteomic similarity tree had consistent topologies. Further, we observed some interesting deviations of the proteomic littorinid tree from the neutral expectations. (1) There were signs of molecular parallelism in two Littoraria species that phylogenetically are quite distant, but live in similar habitats. (2) Proteome divergence was unexpectedly high between very closely related Littorina fabalis and L. obtusata, possibly reflecting their ecology-driven divergence. (3) Conservative house-keeping proteins were usually identified as markers for cryptic species groups ("saxatilis" and "obtusata" groups in the Littorina genus) and for genera (Littoraria and Echinolittorina species pairs), while metabolic enzymes and stress-related proteins (both potentially adaptively important) were often identified as markers supporting species branches. (4) In all five Littorina species British populations were separated from the European mainland populations, possibly reflecting their recent phylogeographic history. Altogether our study shows that proteomic data, when interpreted in the context of DNA-based phylogeny, can bring additional information on the evolutionary history of species.

Distribution characteristics of the fish assemblages to varying environmental conditions in artificial reefs of the Jeju Island, Korea.

Artificial reefs (ARs) have long been practiced to manage and enhance fisheries resources worldwide. Here, we aimed to identify relevant indicator species for the specific environmental conditions of ARs by comparing fish diversity against control sites (Conts). We used a combination of non-metric multidimensional scaling and indicator value analysis to identify the indicator species of the specific AR environments. More individuals and species of fish were present in ARs compared to Conts. Water temperature over the seasons was the most important environmental factor associated with the trophic group composition of fish. In particular, macrocarnivores and benthic invertivores/cleaners closely reflected habitat conditions in a consistent manner. Some dominant fish species were detected at all sites, while the indicator species were more predominant under certain environmental conditions. Altogether, ARs should be monitored at regular intervals to optimize management of their health by detecting the community representativeness via indicator species.

The structure and diversity of freshwater diatom assemblages from Franz Josef Land Archipelago: a northern outpost for freshwater diatoms.

We examined diatom assemblages from 18 stream and pond samples in the Franz Josef Land Archipelago (FJL), the most northern land of Eurasia. More than 216 taxa were observed, revealing a rich circumpolar diatom flora, including many undescribed taxa. Widely distributed taxa were the most abundant by cell densities, while circumpolar taxa were the most species rich. Stream and pond habitats hosted different assemblages, and varied along a pH gradient. Diatoma tenuis was the most abundant and ubiquitous taxon. However, several circumpolar taxa such as Chamaepinnularia gandrupii, Cymbella botellus, Psammothidium sp. and Humidophila laevissima were also found in relatively high abundances. Aerophilic taxa were an important component of FJL diatom assemblages (Humidophila spp., Caloneis spp. and Pinnularia spp.), reflecting the large and extreme seasonal changes in Arctic conditions. We predict a decrease in the abundance of circumpolar taxa, an increase in local (α-) freshwater diatom diversity, but a decrease in regional diversity (circumpolar homogenization) as a result of current warming trends and to a lesser extent the increasing human footprint in the region.

Urbanization effects on the host/parasite relationship in fishes from tributary streams of Pirapó River, Paraná State: assessment of potential environmental bioindicators / Efeitos da urbanização na relação parasito/hospedeiro em peixes provenientes de riachos tributários do rio Pirapó, Estado do Paraná: avaliação de potenciais bioindicadores ambientais

A parasitological study was conducted with 131 fishes belonging to the following species: Poecilia reticulata and Rhamdia quelen species. Samplings occurre d in tributaries streams of Pirapó River, located in the urban and rural area on the surrounding of Maringa city, State of Paraná. The aim of the study was to evaluate the use of fish endoparasites to determine the environmental quality of streams. There was a high similarity between parasites species considering both sets of environments. No influence of streams groups (urban and rural) on the parasites (Sebekia oxycephala and Cucullanus (Cucullanus) pinnai) prevalence and abundance was found. The Relative Condition Factor (Kn) was not different in urban and rural environments to P. reticulata species, but in R. quelen it was significantly higher in urban environments. The parasitism does not interfere in Kn, but was statistically significant in females of P. reticulata when evaluated separately by environment (urban and rural). In urban environments, the parasite S. oxycephala becomes more pathogenic resulting in lower Kn in P. reticulata females. In these, the parasite abundance resulted in negative correlation with Kn in urban streams, suggesting parasite potential damaged action in the anthropized streams. It was verified that the parasite species S. oxycephala and Cucullanus (C.) pinnai are inadequate as bioindicators of environmental quality.

Um estudo ictioparasitológico foi realizado com 131 peixes pertencentes às espécies: Poecilia reticulata e Rhamdia quelen. As amostragens foram realizadas em riachos tributários do rio Pirapó, localizados em áreas urbanas e rurais no entorno da cidade de Maringá, Estado do Paraná. O objetivo do estudo foi avaliar o uso de endoparasitas de peixes para determinar a qualidade ambiental dos riachos. Houve uma alta similaridade entre as espécies de parasitos identificados em ambos os ambientes estudados. Não foi observada influência dos grupos de riachos (urbanos e rurais) sobre a prevalência e abundância dos parasitos (Sebekia oxycephala e Cucullanus (Cucullanus) pinnai). O Fator de Condição Relativo (Kn) não diferiu entre os ambientes urbanos e rurais para a espécie P. reticulata, porém em R. quelen foi significativamente mais elevado em ambientes urbanos. O parasitismo não interfere no Kn, mas foi estatisticamente significante em fêmeas de P. reticulata quando avaliadas separadamente por ambiente (urbano e rural). Em ambientes urbanos, o parasito S. oxycephala se torna mais patogênico, resultando em menores Kn em fêmeas de P. reticulata. Neste caso, a abundância parasitária resultou em correlações negativas com o Kn em riachos urbanos, sugerindo uma potencial ação expoliadora nos riachos antropizados. Foi verificado que as espécies de parasitos S. oxycephala e Cucullanus (C.) pinnai são inadequadas para bioindicação da qualidade ambiental.