Chirocephalus marchesonii is a fairy shrimp endemic to the Pilato Lake, a small temporary high-elevationlake (1948 m a.s.l.) located in the Central Apennines (Italy). The species is of particular conservation interest,since it has limited thermal tolerance, low dispersal capacity and is represented by a single population with a veryrestricted range. The anthropogenic pressure linked to summer tourism and the habitat’s vulnerability to climatechange represent the main threats to the species. Concern over the population’s persistence has been increased bya period of total drying of the lake in summer 2017, which was attributed to earthquakes that occurred in 2016 andwere judged to have altered the hydrogeological conditions. Our study aims were to: i) evaluate the conservationstatus of C. marchesonii and its habitat; ii) examine the influence of environmental parameters on the zooplanktoncommunity, with special reference to C. marchesonii population densities; and iii) provide information to underpineffective conservation strategies. The zooplankton community was monitored monthly from July to November2018 and from June to August 2019, using a Ruttner bottle and an 80-μm mesh net within transects of known length.On each sampling occasion, 13 physicochemical parameters were measured, and water-level fluctuations and lakesurface area were recorded. Higher air temperatures seem to be a key driver of drying events, whereas we identifiedno significant differences in water physicochemistry compared to the past. The mean estimated population densityof C. marchesonii (0.06 individuals L–1) showed that, despite the 2017 drying event, the species completed its lifecycle during the study period, although its population densities were lower than previously recorded. Our resultscan inform extinction risk assessment and associated management strategies, such as the identification of alternativehabitats with the potential to support C. marchesonii populations.Keywords: anostracan crustaceans; endangered species; drought; global

Translocations and releases of farm-reared birds are considered among the major drivers of genetic pollution with consequent loss of genetic diversity in wild populations. In this study, we aimed to assess the extent of hybridization and introgression in the Italian partridges as a consequence of translocation. We surveyed two mitochondrial markers and one nuclear marker of Alectoris and Perdix from collections (museums and private collections), extant wild populations and farms. Consistent with previous studies, we found haplotypes of allochthonous species within the same genus, likely due to introductions for hunting activities. In addition, we found hybrids between Perdix and Alectoris species with genetic markers from both genera in single individuals. Such introgression was bidirectional and in both mitochondrial and nuclear markers. Counterintuitively, most of the hybrid samples came from collections before the 1950s, when large-scale translocations started, from wild populations where Grey Partridge (Perdix perdix) and Rock Partridge (Alectoris graeca) overlap in their distribution, whereas only one hybrid occurred among the farmed birds. Our results suggest that Perdix and Alectoris species can hybridize in nature and that artificial translocations and releases of farm-reared birds for restocking or reintroduction purposes may be only partially responsible for the genomic mismatches of Italian partridges.

High-elevation ephemeral waters are sentinels of climate change, as they quickly respond to decreasing precipitation levels and increasing air temperatures. Fairy shrimps are among the most threatened invertebrates in ephemeral waters, as they are extremely vulnerable to habitat loss. Chirocephalus sibyllae is a fairy shrimp endemic to the Palazzo Borghese temporary pond, located within Sibillini Mountains National Park (Central Italy). The aims of the present study were to: (i) evaluate the physicochemical characteristics of C. sibyllae habitat, with special reference to climate changes over twenty years; (ii) document the life history, size, and abundance of C. sibyllae; and (iii) document the coexisting zooplankton fauna in Palazzo Borghese pond. The zooplankton community was monitored fortnightly, during the filling phases of the pond, from April 2019 to June 2021, using an 80 μm mesh net, within transects of known length. On each sampling occasion, 13 physicochemical parameters were measured, and water-level fluctuations and pond surface area were recorded. Compared to what was reported in the literature, in the last two years the wet phase of the Palazzo Borghese pond was shorter, and the pool dried up much earlier than in the past. The water quality was good and reflected the typical characteristics of high-mountain oligotrophic ponds. Orthophosphates seem to play a key role in zooplankton population abundance, increasing over time during the filling period. According to the extreme unpredictability of environmental features, the zooplankton community was composed of a very limited number of species, adapted to face drought conditions for most of the year. C. sibyllae life-history traits showed a high number of cysts in the broodpouch of ovigerous females (mean ± SD = 66.0 ± 38.9), and a higher mean total length of adults (1.72 cm for females and 1.76 cm for males), in comparison to data reported in the literature. The year 2019 was configured as the season with the most favorable conditions for the development of C. sibyllae; in 2020, the short duration of the pond did not allow the species to complete its life cycle. Climate change seems to pose the main threat to the species, considering that the progressive increase in air temperatures and the decrease in snowfall will, likely, lead to increasingly shorter filling phases of its habitat.

Temporary high-elevation lakes represent vulnerable and unstable environments strongly threatened by tourism, hydrogeological transformations and climate changes. In-depth scientific knowledge on these peculiar habitats is needed, on which to base integrated and sustainable management plans. Freshwater diatoms, thanks to their high diversity and their particular sensitivity to the water chemistry, can be considered powerful ecological indicators, as they are able to reflect environmental changes over time. The aim of the present study was to analyze the diatomic diversity of the Pilato and Palazzo Borghese lakes, two small temporary high-mountain basins, falling in a protected area within the Apennine mountains chain (central Italy). Diatoms data were collected, at the same time as 12 physicochemical parameters, through six microhabitat samplings, from 17 June to 30 August 2019. In both lakes, a total of 111 diatomic species and varieties were identified. The most species-rich genera were Gomphonema, Navicula, and Nitzschia. The Pilato Lake showed a diatomic community dominated by few species, favored by more stable and predictable environmental conditions than the Palazzo Borghese Lake, which hosted a more diversified community, guaranteed by greater spatial and temporal heterogeneity. Both lakes were characterized by the presence of diatomic species typical of good quality waters. The occurrence of numerous aerial species reflected adaptation strategies adopted to colonize environments subjected to extended drought periods. Endangered diatomic species of particular conservational interest were recorded, confirming the need to preserve their habitats.