Intermittent rivers, common in dry parts of the world, such as the Mediterranean region, are hydrologically harsh habitats characterized by periodical flow cessation. Ephemeroptera are aquatic ...insects common in both lotic and lentic waterbodies, where they show a high sensitivity to anthropogenic modifications of their habitat. Therefore, they are widely used as bio-indicators of the freshwater’s health. However, mayfly assemblages and their ecological requirements in the karst Mediterranean intermittent habitats are still not sufficiently known. Thus, the work presented here includes an analysis of mayfly assemblages and their relationship with environmental variables in the lotic phase of four intermittent rivers in the karst Mediterranean region of Croatia. Considering that the studied intermittent rivers are hydrologically extreme environments, a total of 12 recorded mayfly species could be considered as rather high species richness. Nevertheless, species richness per river was quite low (between three and six), and was highly influenced by river morphology, physico-chemical water properties (especially conductivity, water velocity, and concentrations of dissolved oxygen), and anthropogenic pressures. Our results could contribute to the mayfly species protection in karst Mediterranean intermittent freshwater habitats in the Balkans, as well as to the development of conservation measures for those threatened habitats.
Assemblages of adult Odonata were studied in four intermittent karst rivers encompassing macrophyte-rich (MRH) and macrophyte-poor habitats (MPH) in southern Europe, where temporary lotic habitats ...are the predominant freshwater type but are still understudied. With a total of 25 recorded species, the studied habitats support species-rich Odonata assemblages, as already shown for intermittent rivers in the Mediterranean. Aquatic macrophyte abundance, conductivity, and water velocity are the most significant determinants of Odonata assemblages in the studied IRES. MRH promote higher Odonata abundance and the taxonomic and functional diversity of their assemblages compared to the MPH. Odonata assemblages in MRH are characterized by higher values of body size and a higher share of species preferring lentic and temporary hydrological conditions. Moreover, their assemblages are characterized by various patterns of nymphal development and drought resilience strategies. In contrast, MPH are preferred by lotic species, with nymphal development all year round and with no specific drought-resisting strategies. Our results contribute to the knowledge of diversity and ecological requirements of dragonflies and damselflies in IRES habitats, which could provide scientific background for future conservation activities and bioassessment protocols of such habitats and their biota.
Intermittent rivers, lotic habitats that cease to flow during the dry periods of the year, make up a large proportion of the world’s inland waters and are an important source of water in arid regions ...such as the Mediterranean. Yet, water resources and riparian habitats in the Mediterranean regions are under diverse anthropogenic pressures, including land-use change. Odonata are widely used as a valuable tool for assessing freshwater ecosystems. Hence, with the aim of inspecting the conservation value of intermittent rivers in the Mediterranean based on the assemblages they support, we studied Odonata adults at four intermittent Mediterranean rivers in the Dinaric Western Balkans ecoregion with respect to the surrounding land-cover heterogeneity. We analyzed several diversity and conservation indices and recorded significant differences in Odonata species richness and Croatian Conservation Odonatological index among the studied rivers. Our findings showed that land use, as a long-term moderate anthropogenic impact, can enhance land-cover heterogeneity and in some cases even lead to increased Odonata diversity in intermittent rivers in the Mediterranean. Intermittent rivers provide habitat for several threatened Odonata species, suggesting the importance of Odonata in planning the conservation activities in these vulnerable ecosystems.
Bats are natural hosts of various coronaviruses (CoVs), including human CoVs, via an assumed direct zoonotic spillover or intermediate animal host. The present study aimed to investigate the ...circulation of CoVs in a bat colony in the Mediterranean region of Croatia. Guano and individual droppings from four bat species were sampled and tested with the E-gene sarbecovirus RT-qPCR, the pan-CoV semi-nested RT-PCR targeting the RdRp gene and NGS. Furthermore, bat blood samples were investigated for the presence of sarbecovirus-specific antibodies with the surrogate virus neutralization test (sVNT). The initial testing showed E-gene Sarebeco RT-qPCR reactivity in 26% of guano samples while the bat droppings tested negative. The application of RdRp semi-nested RT-PCR and NGS revealed the circulation of bat alpha- and betaCoVs. Phylogenetic analysis confirmed the clustering of betaCoV sequence with SARS-CoV-related bat sarbecoviruses and alpha-CoV sequences with representatives of the
subgenus. The results of sVNT show that 29% of bat sera originated from all four species that tested positive. Our results are the first evidence of the circulation of SARS-CoV-related coronaviruses in bats from Croatia.
Natural history museum collections are essential for understanding biodiversity and environmental changes, especially in large cities with rapid urbanization. While the collaboration between curators ...and taxonomists with ecologists becomes more frequent, the museum collections still are not used to their full potential. This study aimed to digitize beetle specimens from Zagreb, which are kept in the Croatian Natural History Museum collections, provide recent nomenclature, analyse the proportion of currently endangered species, georeference, and compare the sampling locations with today’s iNaturalist citizen science records, as well as land cover changes between the time of collection creation and now. Comparing the sampling locations of collection specimens and citizen science records, it is possible to track the city’s expansion. Beetle family composition is more similar in the city centre than on the outskirts of Zagreb, where land cover changes are more pronounced. The districts in the northern part of Zagreb held higher numbers of threatened saproxylic beetles in both museum collections and citizen science records, highlighting the importance of urban parks and forests and providing insights into potential conservation threats. Museum collections have proved to be a valuable source of biodiversity records frozen in time, helping us track the urban beetle fauna decline.
Temporary pools are small and shallow freshwater habitats with a recurring dry phase and intermittent stagnant water. They are particularly well represented in semiarid and karstic regions of the ...world, where they form during the lentic phase of intermittent rivers and streams. Despite the increasing research interest in such habitats, community ecology studies are still rare, and thus far, have mostly focused on the lotic hydrological phase. Mayflies are among the most abundant benthic macroinvertebrates in freshwater ecosystems, showing high sensitivity to habitat degradation, which makes them widely used in bio-monitoring programs. Mayfly taxonomic and functional diversity, as well as their relationship with environmental variables, were investigated in the temporary pools formed during the lentic phase of three karst intermittent rivers in the Mediterranean. Pools were characterized by river-specific species composition. However, mayfly taxonomic and functional diversity metrics were comparable among the pools of the three rivers. They were influenced by distance from the river’s source and physicochemical water properties, particularly water temperature, conductivity, chemical oxygen demand, and nitrate concentration. Those are related to habitat morphology, substrate composition, and the level of anthropogenic impact. Although the investigated small and shallow temporary pools represent rather harsh habitats, they were inhabited by some species rare in Croatian freshwater habitats (
Procloeon pennulatum
and
Nigrobaetis niger
). Our findings suggest that the conservation value of Mediterranean intermittent rivers does not rest upon a single hydrological phase, but upon an interchange of different phases.
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