Age, size and body condition do not equally reflect population response to habitat change in the common spadefoot toad Pelobates fuscus

Urbanization impacts biodiversity both directly through physical expansion over land, and indirectly due to land use conversion and human behaviors associated with urban areas. We assessed the response of a common spadefoot toad population (Pelobates fuscus) to habitat loss and fragmentation resulting from urban development by studying changes in size, body condition and age parameters. We compared samples collected in the early 2000s (sample A) and later on during 2012–2014 (sample B). The terrestrial habitats in the study area were severely reduced and fragmented due to the expansion of the human settlement. We found no significant differences in the age parameters between the two sampling periods; the median lifespan shortened from 3.5 (sample A) to 3.0 years (sample B), while the other age parameters were similar in both samples. In contrast, snout-vent length, body mass and body condition experienced a significant decrease over time. Our results suggest that changes in body size and body condition, rather than age parameters, better reflect the response of the common spadefoot toad population to declining habitat quality. Therefore, body measurements can provide reliable estimates of the impact of habitat degradation in amphibian populations.

An unusually coloured individual of the common spadefoot toad Pelobates fuscus (Laurenti, 1768)

The background colouration of the spadefoot toad Pelobates fuscus, an anuran species found in Europe is typically light grey/yellow grey/light olive-green. However, an atypical specimen, whose background was brightly coloured yellowish green (light green/lime/yellow coloured), with darker small spots distributed through dorsal parts and four main spots slightly shaped was observed in Poland (Great Poland, Mościejewo village), near to two ponds. The ecological effects of green coloured individual can be adaptively important, through its similarity to the vegetation (predator avoidance).

On the Distribution of the European Common Spadefoot, Pelobates fuscus (Pelobatidae, Amphibia) in Moscow

The European common spadefoot, Pelobates fuscus, has not been observed in Moscow since the end of the 20th century. The species is listed in the Red Data Book of Moscow (2017) as endangered or completely extinct. The paper presents new findings of P. fuscus on the territory of the city, namely, in the “Moskvoretskiy” Natural-Historical Park and the “Kosinskiy” Natural-Historical Park in August 2020.

Analysis of the common spadefoot toad (PELOBATES FUSCUS) skin secretions on the presence of the potential hemostasis system effectors

Since nowadays the chemical synthesis of new bioactive compounds is a complicated and expensive procedure, alongside with the increased price for drugs based on synthetic biologically active compounds, scientists lay emphasize on natural sources as a promising raw material for various biologically active substances. Amphibian skin glands secretions are a powerful source of potential pharmacological agents. Currently their antimicrobial, antiviral, cardiotonic and antidiabetic activities have been studied in detail, although almost nothing is known about the effects of the tailless amphibians' skin secretions on the functioning of the hemostasis system. The aim of this study was to analyze the potential effects of the components of skin glands secretions of a representative of Ukrainian batrakhofauna – the Common spadefoot toad (Pelobates fuscus) on some parameters of hemostasis system. In the result of chromatographic separation of general skin secretions, 4 protein fractions were obtained, containing a variety of proteins with molecular masses ranging from 17 to 150 kDa. The components of fraction 1 activated prothrombin and factor X in plasma. Several components of fraction 4 had proteolytic activity and substrate specificity for collagen. The components of fractions 1 and 2 prolonged plasma coagulation time in the APTT. Thus, it was proved the presence of biologically active compounds in the P. fuscus skin secretions, that indicates the prospects for further research to identify the individual components responsible for the manifestation of the shown effects in order to provide clues in understanding the structural and functional characteristics and mechanism of action. Moreover, advances in this area will further increase the use of amphibian skin secretions as a raw material for the development of new original pharmaceutical agents and/or biotechnological products