The aim of this study was to gather more informations about the biological characteristics of Procambarus clarkii and to investigate the reasons of its rapid expansion in Lake Trasimeno. Specimens of both sexes (544 males and 624 females) were collected from October 2000 to November 2001. During the sampling period physical factors such as water temperature and hydrologic level of LakeTrasimeno were recorded. The study was conducted monthly in order to assess this species’ reproductive period. 1,168 specimens were analyzed for colour, sex, weight, and length. The sexual maturation of gonads was investigated in females. The results of this study evidenced that the population is in expansion, showing that Lake Trasimeno is an optimal habitat for this species. Le but de cette étude est d’avoir plus d’informations sur la biologie de Procambarus clarkii et d’enquêter sur les raisons qui sont à la base de son expansion rapide dans le Lac Trasimeno. Exemplaires des deux sexes (544 mâles et 624 femelles) ont été capturés d’octobre 2000 à novembre 2001. Pendant cette période ont été relevés les paramètres physiques comme la température de l’eau et le niveau du lac. L’étude a été menée mensuellement afin d’évaluer la période de reproduction de cette espèce. 1 168 exemplaires ont été analysés selon la couleur, le sexe, le poids, la longueur et le degré de maturité des gonades a été relevé pour les femelles. Les résultats de cette étude ont mis en évidence que la population de Procambarus clarkii est en expansion et il semble que le Lac Trasimeno soit un habitat optimal pour cette espèce
In human and wildlife populations, the natural microbiota plays an important role in health maintenance and the prevention of emerging infectious diseases. In amphibians, infectious diseases have been closely associated with population decline and extinction worldwide. Skin symbiont communities have been suggested as one of the factors driving the different susceptibilities of amphibians to diseases. The activity of the skin microbiota of amphibians against fungal pathogens, such as Batrachochytrium dendrobatidis, has been examined extensively, whereas its protective role towards the cutaneous infectious diseases caused by Amphibiocystidium parasites has not yet been elucidated in detail. In the present study, we investigated, for the first time, the cutaneous microbiota of the Italian stream frog (Rana italica) and characterized the microbial assemblages of frogs uninfected and infected by Amphibiocystidium using the Illumina next-generation sequencing of 16S rRNA gene fragments. A total of 629 different OTUs belonging to 16 different phyla were detected. Bacterial populations shared by all individuals represented only one fifth of all OTUs and were dominated by a small number of OTUs. Statistical analyses based on Bray-Curtis distances showed that uninfected and infected specimens had distinct cutaneous bacterial community structures. Phylotypes belonging to the genera Janthinobacterium, Pseudomonas, and Flavobacterium were more abundant, and sometimes almost exclusively present, in uninfected than in infected specimens. These bacterial populations, known to exhibit antifungal activity in amphibians, may also play a role in protection against cutaneous infectious diseases caused by Amphibiocystidium parasites.
Seventeen years after the publication of the last checklist of the damselflies and dragonflies found in Italy, an updated list has been compiled. This list reports 95 species belonging to 10 families and 38 genera and includes 2 national endemic and 1 sub-endemic species. Compared to the previous checklist, three species were removed, two subspecies were granted species status, and 10 species were added as new taxa for Italy. The checklist summarizes the current state of the knowledge on the geographical distribution of the Italian species with a regional detail. After the online publication of this dataset on the LifeWatch Italy website in 2021, some minor updates will be included in future releases. The newly discovered species are the result of increased exploration of the national territory combined with some possible range shifts, especially of Libellulidae species of Afro-Asiatic origin. This increased coverage of the country is the result of the efforts of many contributors. It stems from the rapidly growing interest in this zoological group, also enhanced by the activation of a nationwide citizen science project promoted by the Italian Society for the Study and Conservation of Dragonflies (Odonata.it).
The mentum deformity incidence in Chironomus plumosus larvae to assess the environmental contamination level in Lake Trasimeno, Central Italy, was investigated. The survey lasted from May 2018 to August 2019. Fifty-one samplings were carried out: 34 in the littoral zone and 17 in the central zone. The deformity assessment was based on 737 and 2767 larval specimens of C.plumosus collected from the littoral and central zones, respectively. Comparison of the larval morphometric variables between normal and deformed specimens highlighted that the deformities did not cause alterations of the larval growth. The deformity incidence amounted to 7.22% in the whole Trasimeno’s ecosystem, reaching 8.28% in the littoral zone and 6.94% in the central zone. Among the different seasonal cohorts, the spring cohort had overall the highest deformity value (11.41%). The deformity type assessment protocol highlighted that the most common deformity type was “round/filed teeth” (64%). The results of this 2018–2019 survey revealed a low deformity incidence, within the background range of relatively low-impacted freshwaters. Comparison with previous investigations (2000–2010) of the same habitat showed a clear decrease of the deformity incidence. This study further contributes to the evaluation of the mentum deformity in chironomids that represent an indicator endpoint of the anthropogenic contamination level in freshwaters.
1 December 2015 in Ecotoxicology and Environmental Safety