Search Results (73)

Understanding the feeding ecology and habitat use of vulnerable shark species is crucial for effective conservation. This study focuses on two large filter-feeding sharks, the megamouth shark (Megachasma pelagios) and whale shark (Rhincodon typus), in Northwestern Pacific waters. Stable isotope analysis (δ¹³C and δ¹⁵N) was conducted on white muscle samples (n = 91) of M. pelagios and fin clips (n = 90) of R. typus, collected via large-mesh drift nets and set nets in Taiwanese waters. In this study, we investigated feeding strategies, ontogenetic dietary shifts, habitat use, and isotopic niche variation in both species. For R. typus, the observed positive correlation between δ¹³C and δ¹⁵N supports the previously proposed active suction filter feeding, as well as implying both a diet with an increasing proportion of higher trophic level prey and an ontogenetic shift. In contrast, M. pelagios displayed a negative correlation, consistent with a previous study associating such patterns with primary or secondary consumers, further aligning with its reported planktonic prey dominance. Both species had increasing δ¹³C with growth, signifying a shift to nutrient-rich habitats. Only R. typus exhibited ontogenetic diet changes (δ¹⁵N). SIBER (Stable Isotope Bayesian Ellipses in R) analysis revealed distinct feeding strategies and habitat use between the two species, potential sexual segregation, and wider isotopic niche widths for males in both species. The findings underscore the importance of considering species-specific behaviors and sex-based differences in conservation strategies. Full article

Red wood ants (RWA), belonging to the Formica rufa species group, play a crucial and fascinating role in Central Europe’s forest ecosystems. They have a high variety of effects, which they exert around their nests. Their generalist feeding on prey in the canopies of trees lowers the frequency of defoliator outbreaks, as well as increases local biodiversity. Nearly half of their diverse diet is insects, including species considered harmful by foresters. They also have a mutualistic relation with honeydew-producing aphids and planthoppers, which connection has unclear effects on the forests. The habit of RWAs building nests could also positively influence soil composition, due to its structure and high amount of organic matter, which could potentially benefit tree growth. RWAs are also known to enhance the species richness of forests by supporting various myrmecophilous species associated with them. In this study, we review the role of RWAs in forest protection, drawing on the literature focusing on Hungary and Central Europe. Full article

Lake Żarnowieckie, one of the largest lakes in northern Poland, hosts a high number of waterfowl during the non-breeding season. This study presents data on bird abundance from two periods. From 1986 to 1990, coinciding with the early colonization of the lake by zebra mussels Dreissena polymorpha, counts were conducted monthly between October and April. From 2011 to 2025, only one count was performed in January. Between 1986 and 1990, the highest numbers of waterfowl were observed in November and December, with maximum counts exceeding 20,000 birds. Three most abundant species—Eurasian coot Fulica atra, tufted duck Aythya fuligula, and mallard Anas platyrhynchos—accounted for 95–98% of all waterfowl. In January, their numbers significantly decreased, remaining low in the following months. This sharp decline mainly affected diving benthivores (tufted duck and Eurasian coot), which exerted strong pressure on prey populations, leading to a rapid decrease in their numbers and forcing a shift in foraging sites. The greatest decrease occurred in seasons with the highest number of waterfowl in December, when diving benthivores were most abundant and applied the greatest pressure on benthic organisms. These seasonal changes suggest that a single January count may not fully represent the significance of the lake for waterfowl. Over the study period, both ichthyophages, the great cormorant Phalacrocorax carbo and great crested grebe Podiceps cristatus, showed substantial increases in number. For cormorants, this growth coincided with the increase in the European population, while the rise in great crested grebes likely exemplifies the establishment of a new wintering site for this species in a location rich in food and free from intense human disturbance. Full article

Cone snails are carnivorous marine predators that prey on mollusks, worms, or fish. They purposefully inject a highly diversified and peptide-rich venom, which can vary according to the predatory or defensive intended use. Previous studies have shown some correlations between the predation- and defense-evoked venoms and specific sections of the venom gland. In this study, we focus on the characterization of the venom of Cylinder canonicus, a molluscivorous species collected from Mayotte Island. Integrated proteomics and transcriptomics studies allowed for the identification of 108 conotoxin sequences from 24 gene superfamilies, with the most represented sequences belonging to the O1, O2, M, and conkunitzin superfamilies. A comparison of the predatory injected venom and the distal, central, and proximal sections of the venom duct suggests mostly distal origin. Identified conotoxins will contribute to a better understanding of venom–ecology relationships in cone snails and provide a novel resource for potential drug discovery. Full article

The species richness of major clades and functional groups among gastropods, a key element of Modern Evolutionary Fauna (MEF), underlines the dominant role of carnivorous Caenogastropoda and Heterobranchia, including small ectoparasites and micrograzers, at modern tropical latitudes. Neogastropoda are active predators that radiated in the Cretaceous, but their early Mesozoic MEF roots are poorly understood. The escalation hypothesis emphasises prey–predator interactions as gastropods’ macroevolutionary drivers during the Mesozoic Marine Revolution but overlooks the significance of highly diversified smaller forms. The tropical fossil record of the Permian–Triassic mass extinction (PTME) and the Triassic rise of MEF suggests that non-carnivorous species dominated gastropod fauna immediately before and after the PTME: Permian micrograzers mainly fed on sponges and waned during the rise of MEF, while ectoparasites and micrograzing carnivores diversified starting from the Ladinian period. Patterns of gastropod species richness, size, and form, the fossil record of reef builders and other benthic invertebrates, and an analysis of stem neogastropods jointly suggest a Middle Triassic revolution of small-sized gastropods, triggered by the emergence of scleractinian corals and the diversification of echinoderms. Habitat heterogeneity and new food sources offered niches for the early radiation of modern gastropod clades. Full article

The Utricularia (bladderworts) species are carnivorous plants that prey mainly on invertebrates using traps (bladders) of leaf origin. On the outer surfaces of the trap, there are dome-shaped glands (capitate trichomes). Each such trichome consists of a basal cell, a pedestal cell, and a terminal cell. During the maturation of these external glands, there are changes in the cell wall of the terminal cell of the gland (deposited layers of secondary wall material). Thus, due to changes in the cell wall, these glands are excellent models for studying the specialization of cell walls. The main aim of this study was to check whether different cell wall layers in terminal gland cells have a different composition in the case of homogalacturonans (low-methylesterified HGs, fully de-esterified HGs, and galactan) and hemicelluloses (galactoxyloglucan, xyloglucan, and xylan). The antibodies were used against cell wall components (anti-pectins JIM5, JIM7, LM19, CCRC-M38, and LM5 and anti-hemicelluloses LM25, LM15, CCRC-M1, and CCRC-M138). The localization of the examined compounds was determined using immunohistochemistry techniques, Carbotrace 680, and Calcofluor White. Our study showed the presence of various components in the cell walls of external gland cells: methylesterified and demethylesterified homogalacturonans, galactan, xylan, galactoxyloglucan, and xyloglucan. In the terminal cell, the primary cell wall contains different pectins in contrast to the secondary wall material, which is rich in cellulose and hemicelluloses. We also found that the basal cell differs from the other gland cells by the presence of galactan in the cell wall, which resembles the epidermal cells and parenchyma of traps. A particularly noteworthy part of the cell wall functions as a Casparian strip in the pedestal cell. Here, we found no labeling with Carbotrace 680, possibly due to cell wall modification or cell wall chemical composition variation. We have shown that the apoplastic space formed by the cell walls of the terminal cell is mainly composed of cellulose and hemicelluloses (galactoxyloglucan and xyloglucan). This composition of the cell walls allows the easy uptake of components from the external environment. Our research supports the external glands’ function as hydropotens. Full article

For almost all the Sicilian islands, there are no faunistic data concerning marine Heterobranchia, which is one of the most sought-after groups of marine critters by photographers and diving enthusiasts all over the world. With the present study, carried out through underwater photography at various dive sites and stretches of coastline in the island of Marettimo, we made the first contribution to the knowledge of the marine Heterobranchia fauna present on this island of the Egadi archipelago. Through data collection, it was possible to document the presence of 43 species of marine Heterobranchia. Data analysis showed a remarkable homogeneity in the number of species between the examined sites. This is probably due to the peculiar environmental homogeneity present in the sites of this island, which are almost all rich in the presence of both benthic suspension feeders (the favorite prey of many groups of marine Heterobranchia) and environments full of crevices, grottos, and vertical walls, which are the preferred habitats of the majority of these mollusks. The higher number of marine heterobranch species found in Marettimo compared to the smaller number of species found on the other recently examined Sicilian islands (Pantelleria, Lipari, and Vulcano) is probably due to the massive presence of rich coralligenous biocoenoses and the particular hydrodynamic regime to which Marettimo is subject. Full article

Spider venoms are emerging as a rich source of bioactive peptide toxins with therapeutic potential. Lynx spiders of the genus Oxyopes are small, cursorial hunters that employ complex venom to subdue arthropod prey. However, extracting crude venom from these diminutive arachnids poses significant challenges. This study presents a transcriptome analysis of venom glands from an undescribed Oxyopes forcipiformis species, revealing 339 putative protein and peptide toxin sequences categorized into seven functional groups. The venom composition was dominated by membrane-active peptides (40.71%), venom auxiliary proteins (22.71%), neurotoxins (15.63%), channel active peptides (7.08%) and uncharacterized components (13.87%). Additionally, phylogenetic analysis of 65 disulfide-bond-rich peptides yielded six distinct families based on sequence homology and cysteine framework. Finally, a novel antimicrobial peptide, GK37, was identified using in silico and homology analyses. Our data suggested that GK37 presented significant antibacterial activity against Gram-positive bacteria Staphylococcus aureus with a minimum inhibitory concentration (MIC) of 1.552 µM by disrupting bacterial membranes. At 4× MICs, GK37 almost showed no hemolytic activity on blood cells or toxicity against Hek293T cells. Our findings provided a basis for targeted studies of the diversity and pharmacological effects of lynx spider peptide. We elucidated a valuable high-throughput approach for obtaining proteins and peptides from small-group spiders. Full article

Daya Bay, a semi-enclosed bay in the northern South China Sea and to the east of the Pearl River Estuary, is rich in biological resources and diverse habitats. Current research on mesozooplankton in Daya Bay has mainly focused on aspects such as species composition, biomass, and biodiversity in the zooplankton community. However, there is limited research on the top-down effects of mesozooplankton on prey communities. This study conducted seasonal in-situ cultivation experiments from 2015 to 2017. By combining mesozooplankton grazing experiments and microzooplankton dilution experiments, the mesozooplankton clearance rate and trophic cascading effect on low trophic levels were calculated. Results showed evident mesozooplankton selective feeding behavior and corresponding trophic cascades with seasonal variations, these being significantly higher in the spring and summer and lower in the autumn and winter. Different sizes of phytoplankton showed significant differences; large-sized phytoplankton received high feeding rates but low trophic cascades by mesozooplankton, while the opposite was true for small-sized phytoplankton. Trophic cascades contribute in three ways: offsetting direct grazing mortality, changing prey community structure via its effects on different phytoplankton sizes, and reducing ciliate grazing impacts at an average of 14.4 ± 7.8%, maintaining around 70% ciliate grazing impacts in nature. The composition of mesozooplankton was the primary reason for explaining feeding preferences, including size selectivity and omnivory. For instance, high cladoceran abundance caused high feeding rates while, on the other hand, high omnivorous copepods abundance caused high trophic cascades on small-sized phytoplankton. General additive model (GAM) analysis revealed that the changes in trophic cascades were highly dependent on temperature, ciliate abundance, mesozooplankton feeding rates on ciliates, and ciliate feeding rates on phytoplankton. The significance of this study lies in its contribution to providing valuable insights into the role of mesozooplankton in the marine food web and their impact on lower trophic levels. In addition, the findings can help inform the management and conservation of marine ecosystems, as well as guide future research in this field. Full article

The common Buzzard (Buteo buteo) was previously shown to transmit two Sarcocystis species (S. glareoli and S. microti) forming cysts in the brains of rodents. Due to a lack of research, the richness of Sarcocystis species spread by these birds of prey is expected to be much higher. A total of 30 samples of the small intestine of the Common Buzzard were collected in Lithuania and subjected to Sarcocystis species identification based on nested PCR of 28S rRNA and ITS1, following the sequencing of amplified DNA fragments. Six known Sarcocystis spp., S. cornixi, S. glareoli, S. halieti, S. kutkienae, S. turdusi, and S. wobeseri, along with three genetically distinct species (Sarcocystis sp. Rod3, Sarcocystis sp. Rod4, and Sarcocystis sp. Rod5), were identified. Phylogenetically, these three potentially new species clustered with Sarcocystis spp. characterised by a rodents-birds life cycle. Sarcocystis spp. employing rodents and birds as their intermediate hosts were detected in 66.7% and 50.0% of samples, respectively. These findings are consistent with the diet preferences of Common Buzzards. Notably, co-infections with two or more species were observed in a half of the samples. Altogether, the obtained results indicate that the Common Buzzard could serve as definitive host of various Sarcocystis species. Full article

The ghost bat Macroderma gigas (Megadermatidae) is native to Australia. Its current distribution has dramatically contracted northwards in the past 150 years and the extant populations are scattered and isolated due to climatic and anthropogenic factors. To investigate the potential for reintroductions of wild ghost bats into suitable habitats, we examined the potential for refuges located in the southern-most parts of the species’ former range to once again support populations. We identified Drovers Cave, located in Drovers Cave National Park in Western Australia, as a potential reintroduction site and used thermo-hygrochron iButtons to demonstrate that the microclimate conditions within the cave are suitable for ghost bats with temperatures close to 20 °C and 99% humidity throughout a ten-month period (December to September). We also showed that in the Pilbara region, ghost bats are opportunistic and flexible predators relying on small birds and mammal species. After comparing these data with the local fauna species list reported from Drovers Cave National Park, we concluded that the habitat at the proposed reintroduction site could provide sufficient diversity of potential prey species in terms of species richness, but we had no data on their relative abundance. Full article

The genus Utricularia (bladderworts) species are carnivorous plants that prey on invertebrates using traps with a high-speed suction mechanism. The outer trap surface is lined by dome-shaped glands responsible for secreting water in active traps. In terminal cells of these glands, the outer wall is differentiated into several layers, and even cell wall ingrowths are covered by new cell wall layers. Due to changes in the cell wall, these glands are excellent models for studying the specialization of cell walls (microdomains). The main aim of this study was to check if different cell wall layers have a different composition. Antibodies against arabinogalactan proteins (AGPs) were used, including JIM8, JIM13, JIM14, MAC207, and JIM4. The localization of the examined compounds was determined using immunohistochemistry techniques and immunogold labeling. Differences in composition were found between the primary cell wall and the cell secondary wall in terminal gland cells. The outermost layer of the cell wall of the terminal cell, which was cuticularized, was devoid of AGPs (JIM8, JIM14). In contrast, the secondary cell wall in terminal cells was rich in AGPs. AGPs localized with the JIM13, JIM8, and JIM14 epitopes occurred in wall ingrowths of pedestal cells. Our research supports the hypothesis of water secretion by the external glands. Full article

In the Pistoia Nursery-Ornamental Rural District (Italy), a leader in Europe in ornamental nurseries covering over 5200 hectares with over 2500 different species of plant, plant-parasitic nematodes represent a serious concern. The potential efficacy of a pot cultivation system using commercial substrates to control plant-parasitic nematodes was assessed. On two different plant species, two different pot cultivation managements, potted plants, and potted plants previously cultivated in natural soil were compared to plants only cultivated in natural soil. The entire soil nematode structure with and without plants was evaluated. The relationship between soil properties and soil nematode community was investigated. All the studied substrates were free from plant-parasitic nematodes. Regarding free-living nematodes, Peat–Pumice showed nematode assemblage established by colonizer and extreme colonizer bacterial feeders, whereas Peat–Perlite included both bacterial and fungal feeders, and, finally, coconut fiber also included omnivores and predators. In farming, the substrates rich in organic matter such as coconut fiber could still play an important role in suppressing plant-parasitic nematodes because of the abundance of free-living nematodes. In fact, they are of crucial importance in both the mineralization of organic matter and the antagonistic control of plant-parasitic nematodes. Potting systems equally reduce virus-vector nematodes and improve the prey/predator ratio favoring natural control. Full article

Dramatic land-use changes in urban landscapes can drive water colour darkening by washing compounds, such as organic matter and iron, from terrestrial ecosystems into urban blue space, consequentially affecting aquatic communities. Here, I studied how pond water colour changes along an urban gradient and how diving beetles (Dytiscidae) respond to the water colour gradient in 11 ponds with fish and 15 ponds without fish in the Helsinki Metropolitan Area, Finland. I found that the pond water colour exhibited a non-significant decreasing pattern along the urban gradient, indicating that urbanisation may not necessarily drive brownification in urban ponds. Dytiscid species richness and abundance exhibited significant positive correlations with increasing water colour in ponds with fish but no significant correlation in ponds without fish. Some species, such as Agabus spp. and Dytiscus spp., appeared tolerant to highly coloured water, whereas some species, such as Hyphydrus ovatus and Hygrotus spp., tended to occur in clear water, indicating that brown water may provide dytiscids with prey refuges, but some species are intolerant to brown water. The study highlights the importance of urban pondscape heterogeneity to meet the needs of aquatic invertebrates that prefer different water colours and for the multifunctioning of urban ponds. Full article

Artificial light at night (ALAN) is a major form of anthropogenic pollution, disrupting nocturnal wildlife behaviour and ecosystem function. Large construction sites are typically located at the intersection of urban and natural areas, introducing intense lighting into previously dark natural habitats. This study examines the responses of bats to intense nighttime lighting at a major construction site associated with a linear transport infrastructure (LTI) project. We used passive acoustic monitoring to record bat activity and species richness at the construction site and in adjacent urban and natural areas with different lighting levels. Generalist species, such as Pipistrellus kuhlii and Nyctalus leisleri, were attracted to illuminated areas, likely due to increased prey availability. Conversely, sensitive species, such as those from the Myotis and Plecotus genera, along with Barbastella barbastellus, avoided illuminated areas, particularly the construction site. Species richness was significantly lower at the construction site compared to other environments, reflecting ALAN’s barrier effect on movements and habitat accessibility for more sensitive species. The findings highlight the ecological impacts of introducing ALAN to previously unlit natural environments, underscoring the urgent need for implementing ALAN mitigation strategies in urban planning and construction practices to protect biodiversity in urbanising areas. Full article