Search Results (5,284)

In the late Cenozoic, the south-west of Eastern Europe was a region affected by extensive hydrological transformations that resulted in the retreat of the Eastern Paratethys and the emergence and further evolution of freshwater communities. In recent decades, a relatively rich fossil actinopterygian fauna has been described from this area. The present study was based on previous systematic studies and aimed to assess and trace the temporal dynamics of the diversity of fish assemblages that existed in the area from the Late Miocene until the end of the Pleistocene. Species diversity, taxonomic diversity, taxonomic complexity, and functional diversity were analysed. It was found that the diversity of the fish assemblages notably decreased during the Late Miocene, when representatives of the families Clariidae, Moronidae, Sciaenidae, and Gobiidae disappeared, and remained relatively low during the Pliocene. During the Pleistocene, however, functional diversity gradually increased, despite fluctuating species and taxonomic diversity and taxonomic richness and complexity, which suggests an increasing stability of the coenotic structure within the fish communities. The revealed temporal trends reflect the impact of the palaeoenvironmental and palaeoecological processes that characterised the region during the late Cenozoic, particularly orogenic and climatic changes, and the evolution of a typical limnophilous, lacustrine-riverine fish fauna. Full article

Sicily, Southern Italy, has important genetic resources for azarole (Crataegus azarolus). The region hosts both spontaneous wild populations and various forms of the genus, some of which belong to well-defined specific or intraspecific taxa, while others are hybrids of unclear origin. Not all wild forms can be considered related to C. azarolus, but those included in the sect. Azaroli and thus C. aronia (= C. azarolus var. aronia), which is widespread in western Sicily, certainly can. All these populations are morphologically distinct but coexist in the same area. This preliminary genetic study aims to establish the genetic relationships between wild populations of Crataegus taxa and azarole (C. azarolus). Furthermore, the research addresses the lack of clear taxonomic information regarding the different phenotypes found in Sicily, including both recognized taxa and those still critically underreported. The study is based on SSR (Simple Sequence Repeat) molecular markers, isolated from other Rosaceae species. The findings indicate that at least two groups affiliated with C. azarolus, yet distinct, are present in Sicilian populations. These results could have significant implications for systematics and taxonomy, as well as for conservation and the valorization of plant biodiversity. Full article

Vector-borne diseases (VBDs) remain a major public health burden, particularly in tropical and subtropical regions. Aedes aegypti mosquitoes are primary vectors of several VBDs, and understanding their population dynamics is critical for developing effective control strategies. This study investigates seasonal sex ratio variation in A. aegypti populations within urban environments of El Salvador’s seasonally dry neotropical biomes. Using data from an ongoing surveillance program, we analyzed the temporal distribution of male and female mosquitoes across eight sampling events. Our results reveal significant deviations from the expected 1:1 sex ratio, with a pronounced female bias during the dry season and a shift toward parity in the wet season. These findings suggest that environmental and anthropogenic factors influence sex ratio dynamics, potentially affecting reproductive success and population persistence. The observed sex ratio distortion has important implications for vector ecology and biocontrol, emphasizing the need to incorporate seasonal and urban ecological variation into vector management strategies. Integrating these ecological insights into biocontrol programs could enhance the effectiveness of interventions aimed at reducing VBD transmission in seasonally dry tropical regions. Full article

The main objective of our study was to determine for the first time the daily vertical migration (DVM) of 15 planktonic ostracod taxa in the southern Adriatic Sea. We analysed the influence of environmental factors on the Weighted Mean Depth (WMD) of these species, considering differences between males, females and juveniles. Planktonic ostracods were collected during a research cruise in July 2003 at a depth of 1200 m. A total of 152 vertical hauls, divided into 19 sample series, were conducted from the surface to the seafloor at standard oceanographic depths at four times of day. The results showed that the species Archiconchoecia striata, Porroecia spinirostris and Conchoecia magna exhibited significant DVM and migrated daily between the surface and deeper waters. In contrast, the species Porroecia porrecta porrecta, Mikroconchoecia curta, Proceroecia procera, Proceroecia microprocera, Discoconchoecia elegans, Paraconchoecia spinifera and Metaconchoecia rotundata showed less movement. Species with subtle DVM were Porroecia porrecta adriatica, Mikroconchoecia echinulata, Proceroecia macroprocera, Paramollicia rhynchena and Loricoecia loricata, reflecting their adaptation to environmental factors such as hydrographic and biological conditions. Our analysis of WMD revealed noteworthy differences in the vertical distribution of ostracods, focussing on their diurnal migration patterns and depth preferences. Full article

Otoliths are common in the fossil record and can provide important insight into the evolution and spatial and stratigraphic distribution of fishes, but have remained understudied in many areas of the world. Here, we describe the first marine otolith assemblage from East Africa. The material is from Tanzania Drilling Project cores of late Eocene to early Oligocene age, spanning the Eocene-Oligocene transition (EOT). The assemblage consists of 10 identifiable species of which 5 are new, and 4 remain in open nomenclature. The new species are as follows: Protanago africanus, Bregmaceros tanzaniensis, Ortugobius pandeanus, “Serranus” plasmaticus, and Acanthocepola signanoae. The association of shallow and deep-water taxa along with the dominance of the family Cepolidae, which has not been observed in either the extant or fossil record, makes the faunal composition unusual. However, when taxon occurrences are correlated with stable isotope records from the same cores and compared with previous studies, it is clear the otoliths reflect the sea-level fall known to occur during the EOT, with deeper dwelling taxa in the late Eocene and taxa preferring shallower, which are more shelf-like environments in the early Oligocene. Full article

Biological control by releasing a large number of parasitoids has been an effective strategy for coping with stored-product pest insects. Habrobracon hebetor (Say) (Hymenoptera: Braconidae) has strong control capabilities over Lepidoptera pests. Exploring the optimum storage temperature, life stage, and cold storage period of H. hebetor is of great importance for the utilization of parasitoids. In this context, the survival, parasitism, and fecundity of H. hebetor were evaluated after 10, 20, 30, 40, 50, and 60 d of exposure at −5, 0, 5, 10, and 15 °C for H. hebetor eggs, larvae, pupae, and adults, and the survival, parasitism, and fecundity of H. hebetor individuals that had been maintained at normal rearing condition were taken as a control. The cold exposure duration dramatically affected the development and survival of eggs, larvae, and pupae of H. hebetor, regardless of the temperatures tested. Habrobracon hebetor eggs, larvae, and pupae failed to develop into the next life stage at −5, 0, and 5 °C. Habrobracon hebetor eggs, larvae, pupae, and adults failed to survive after 10 d exposure at −5 and 0 °C. The parasitism rate, fecundity and oviposition duration of H. hebetor adults that originated from eggs, larvae, pupae, and adults after different cold storage durations markedly decreased with increasing cold storage duration. The highest parasitism rate of adults was 34.12% after exposure at 5 °C for 10 d, which was not significantly different from the control (31.86%). The maximum level of egg production of H. hebetor adults developed from initial larvae exposed at 15 °C for 10 d and 20 d were 344.67 and 340.67 eggs/female, respectively, which were not significantly different from the control (392.00 eggs/female). When H. hebetor larvae were stored at 15 °C for 10 and 60 d, the oviposition duration of newly emerged adults reached the maximum and minimum levels recorded, with 17.00 and 0.83 d, respectively. These results provide empirical support for the large-scale production and storage of H. hebetor. Full article

Apomictic populations, which produce seeds with embryos without proper sexual syngamy, often show low genetic diversity, but eventually, such diversity has been reported to be surprisingly high. We studied here the genetic diversity in agamic complexes of Eriotheca crenulata (comb. n. E. gracilipes), E. pubescens (Malvaceae-Bombacoideae), and Handroanthus ochraceus (Bignoniaceae), tropical tree species from the savannas in Central Brazil. We evaluated the genetic diversity and structure of self-fertile polyploid sporophytic apomicts versus self-sterile diploid or tetraploid sexual populations by using dominant ISSR markers. Genetic diversity was either similar or even higher in apomictic populations of E. crenulata and E. pubescens, but the opposite was observed in some populations of H. ochraceus. Only two individuals of E. pubescens showed identical ISSR profiles, so strict clonality in adult individuals was very rare among the studied trees. The genetic variability was notably higher within populations than among populations of H. ochraceus and very similar among and within populations of Eriotheca species. Ordination, clustering, and Bayesian analyses showed a clear distinction between populations of Eriotheca species with different breeding systems. But for H. ochraceus, a sexual population was actually grouped with the apomictics. As in other studies, eventual sexual and recombination events seem to increase genetic diversity in apomictic populations. This may explain the similar genetic diversity among apomictic and sexual populations in the studied agamic complexes and the virtual absence of strict clonal individuals. The results have evolutionary and ecological consequences for the threatened Neotropical savanna trees. Full article

To avoid the spread and environmental impacts of the European catfish (Silurus glanis), which arrived in Portugal around 2006, it is fundamental to understand anglers’ behaviors and perceptions. To address this need, 339 Portuguese anglers were surveyed online and face-to-face and divided into two groups (catfish anglers, n = 115; and non-catfish anglers, n = 224). The majority of surveyed anglers were males (>95%) who consider that catfish is not beneficial to the development of angling (>62%) and acknowledge its negative impact on other fish species (>84%), mainly by predation (>89%). Catfish anglers perceive the species as more positive for angling and for other fish species. Principal Component Analysis showed that anglers’ behaviors are mainly driven by their awareness of the impacts of European catfish and by their angling experience. Regression modeling inferred the probabilities of two anglers’ behavior (targeting catfish and practice of catch and release) and one perception (catfish is beneficial to angling), which are considered promoters of catfish invasion, and detected strong correlations among these three variables. Therefore, it is strongly advised to implement an educational and law enforcement program to stop illegal practices that promote the dissemination of invasive fish species like European catfish. Full article

The aim of this paper is to describe and analyse the present Swedish fauna of freshwater snails, based on material in museum collections, the literature, records in conservation reports and in databases. The Swedish fauna comprises 50 species (42 indigenous and 8 introduced). Moreover, 31 out of 50 species belong to the superorder Hygrophila. The species’ zoogeography, ecology and conservation status are highlighted. The species distributions can roughly be classified according to four different geographical groups of patterns. 23 species have their northern limit within or close to the limes norrlandicus, an important biogeographical transition zone in Central Sweden. The history of the exploration of the fauna and groups/species with taxonomical/determination problems are discussed. The six species, which are present in the Swedish National Red List, are discussed in detail. Main threats include the exploitation of Swedish rivers and the changing of insolation in small water bodies due to vegetation alteration, eutrophication and drainage. The threat status of the species in the national Swedish list and the general European list are compared and show a high degree of agreement. Full article

This study investigated the fish species composition and environment of the Emur River, a tributary of the Upper Heilongjiang (Amur) River system, which is a typical extreme-cold region of China. From 2022 to 2024, 28 native species (27 species of fish and 1 species of lamprey), including 4 endangered species, were monitored from 14 sampling sites. When grouped according to the main stream vs. tributaries and summer vs. autumn, we found significant differences (p < 0.05) in the composition of the fish communities. In autumn, the main stream fish assemblage was dominated by common species that prefer a slow current, including Phoxinus phoxinus (33.7%), Lota lota (25.2%), and Phoxinus lagowskii (19.8%). The tributary fish assemblage was primarily composed of typical coldwater fish species, such as L. lota (48.9%), Cottus poecilopus (20.2%), and Thymallus grubii (18.1%). However, in summer, there was no significant difference between the main course and tributaries. Canonical correspondence analysis showed environmental factors, including water temperature, elevation, and dissolved oxygen, to have significant impacts on the fish distribution to an extent that varied with species. This study may contribute to the management of coldwater fish diversity in mountain rivers and the protection of aquatic species habitats in regions of extreme cold. Full article

Understanding soil microbial community assembly in endangered mangrove ecosystems is crucial for ecological conservation. This study investigated the diversity and drivers of soil microbiomes across Barringtonia racemosa communities (pure: T1; associated: T2, T3) in China’s Leizhou Peninsula, using SMRT sequencing and phospholipid fatty acid analysis. The results reveal that pure B. racemosa communities (T1) harbored the highest microbial diversity (Chao1: 2980 bacteria, 14,378 fungal OTUs), with Pseudomonadota (37.6%) and Ascomycota (52.6%) as dominant phyla. Fungal communities exhibited 3.2-fold higher β-diversity variability than bacteria across communities (Bray–Curtis; p < 0.01). Redundancy analysis identified soil organic carbon (SOC), available nitrogen (SAN), and leaf manganese as primary drivers, collectively explaining 72.4% of microbial variation (p = 0.003). Notably, pure communities showed an elevated SOC (74.3 mg/kg) and fungal: bacterial ratio (0.19 vs. 0.13–0.14 in associated communities), indicating fungal dominance in carbon-rich sediments. Conversely, rice field controls displayed distinct SAP/SAK patterns reflecting agricultural impacts. These findings demonstrate that the B. racemosa community structure differentially regulates fungal assemblages more strongly than bacterial communities, providing critical insights for mangrove restoration through microbial-informed management. Full article

Conservation of rare plant species diversity is often found within the context of disturbance and land use planning. In mountainous regions, globally, critical plant conservation issues can occur at esthetically pleasing topoedaphic positions, such as popular mountain summits. Here, we assess the spatiotemporal ecology of an imperiled cushion plant assemblage in such a situation. Plant community dynamics of three rare cushion plant species [scented pussytoes (Antennaria aromatica), Howard’s alpine forget-me-not (Eritrichum howardii), and Shoshone carrot (Shoshonea pulvinata)] were measured at a 2475 m mountain summit near Cody, WY, USA. The survey was conducted in the summer of 2017–2019 using 1 m² quadrats across three macroplots (ranging from 295 to 2250 m² in size) to estimate all vascular plant species abundance. Altitude, canopy height, vegetative cover, standing dead biomass, rock, litter, and bare soil were also measured. We assessed annual changes in abundances, richness (#), evenness (N2/N1), and diversity (H′) and performed a constrained ordination to understand ecological drivers of distribution. Nineteen total plant species were identified, all of which were native perennial species. Five additional species were also noted to be species of conservation concern. For the three rare cushion plants of focus, abundance did not significantly change over the three-year period. Species richness was lower in 2017 than in subsequent years, but there was no difference in evenness or diversity. In the constrained ordination, the first axis explained 56.1% of the variation and was attributed to the rock-to-vegetation gradient of the environment, while the second axis explained an additional 28.7% of the variance and was attributed to altitude. The three rare cushion plants of focus appeared to segregate and occupy differential habitat niches. The popularity of this mountain peak, coupled with the presence of a diverse rare cushion plant community, should facilitate the careful monitoring and management of tourism to ensure the conservation of diversity. Full article

The impact of agricultural practices and changes in land use on soil microarthropod communities was investigated by analyzing the data from 53 sample sites with five different land-use categories (natural habitats, orchards, arable crops, olive groves and vineyards). These datasets are a mix of published and unpublished studies and were analyzed using statistical techniques that enabled a determination and comparison of the values of the biological soil quality index for each of the five land-use systems based on the richness and community composition of the biological forms of the microarthropods identified (QBS-ar), and the chemical and physical properties of the soil [e.g., pH, soil organic carbon (SOC), dominant particle sizes present (e.g., clay) and texture] for each locality. Our results confirm that different agricultural practices diminish, in different ways, the dominance and variety of species present in soil microarthropod communities. Furthermore, these agroecosystem communities represent a sub-sample of the soil microarthropod communities found in natural habitats; presumably due to the stress factors experienced from impact(s) of the differing chemical and physical properties of the soils, and the resultant selection pressures placed upon the biological forms present in the soil. Full article

Terrestrial small mammal species typically assemble according to plant communities, but multiple factors, including large-scale geographic patterns, influence their assemblage structure. Despite their ecological significance, small mammals are often underrepresented in biodiversity assessments, and many Polish national parks lack comprehensive surveys. This is also the case for Wolin National Park (WNP), Poland’s only national park on a coastal marine island, which is known for its unique bat fauna. Here, we surveyed small mammals in WNP using live and pitfall trapping, identifying only nine species—the lowest richness among the five regional national parks (which host 11–13 species based on trapping data alone). Rarefaction analysis indicated a very low probability of detecting additional species with further sampling. This unexpectedly low richness is likely linked to insular isolation and the park’s location at the edge of the regional distributions of three species. Cluster analysis revealed a key pattern in WNP’s small mammal assemblages: a division between two distinct landscape units—moraine hills and the alluvial delta—where Apodemus flavicollis and Apodemus agrarius were the predominant species, respectively. This division had a greater influence on assemblage clustering than local vegetation. Full article

The number of recreational marinas has increased in recent years due to the growing demand for leisure boating. Recreational marinas are key points for the introduction of non-indigenous species (NIS), which are considered a source of biocontamination. However, there is scarce knowledge on the influence of environmental features on NIS fouling assemblages, especially regarding different salinity conditions. The aim of this study is to explore the effect of salinity on the structure of NIS fouling assemblages and biocontamination levels. Therefore, fouling assemblages associated with floating pontoons were studied in recreational marinas located in fully marine and brackish habitats on the Northern Portuguese coast. Twenty-four NIS were found, of which arthropods and bryozoans represented the most abundant taxa. Except for NIS abundance, univariate and multivariate analyses showed that NIS assemblage structure was shaped by salinity conditions. Thus, NIS richness and the ratio between NIS richness and total richness were significantly higher in marine than in brackish habitats. Similarly, consistently higher biocontamination levels were found in marine habitats, compromising their ecological status. Quantitative data provided here will be useful in the development of NIS management strategies. Thus, in Northern Portugal, efforts should be focused on marinas under fully marine salinity conditions because they harbor a greater number of NIS and, consequently, a worse ecological status. Full article