MORPHOLOGY OF FROGS OF THE GENUS PELOPHYLAX ALONG THE BANKS OF THE DESNA RIVER, CHERNIHIV

Abstract

The destruction of natural habitats as a result of war, as well as advancing urbanisation, pose a pressing challenge for the conservation and, ultimately, the restoration of natural ecosystems. Amphibians are identified as one of the most vulnerable groups of animals in terms of their response to environmental changes. One of the reasons for the decline in amphibian populations is the increasing human impact on the natural environment. In urban areas, changes in the structure of amphibian populations have been observed, along with an increase in the incidence of diseases and abnormalities in development and morphology.

Purpose of the work. The aim of this study is to analyse morphological characteristics, determine species affiliation, examine features of sexual dimorphism, and identify possible diseases and developmental abnormalities in frogs of the genus Pelophylax found in the riparian zone of the Desna River.

Methodology. Frogs of the genus Pelophylax were caught using a landing net or by hand. The captured animals were placed in a linen bag, which was periodically moistened to prevent their skin from drying out or overheating. Descriptions of morphological characteristics, such as colouration and the pattern on the back and belly, as well as morphometric measurements, were carried out whilst the animals were still alive, after which they were released back into the area where they had been caught. Measurements were taken using an electronic vernier caliper, accurate to the nearest hundredth of a millimetre. Statistical analysis was carried out using the Statistica software package for Windows, taking into account the small sample size. The presence of lesions of various aetiologies and developmental abnormalities was also recorded.

Scientific novelty. This study is the first to conduct a comprehensive investigation of the morphometric characteristics, lesions of various aetiologies and developmental abnormalities in green frogs of the genus Pelophylax inhabiting the riparian zone of the Desna River within the city of Chernihiv.

Conclusions. Based on morphological characteristics, the green frogs of the genus Pelophylax found in the coastal strip of the Kordivka area in Chernihiv are provisionally classified as belonging to the species Pelophylax ridibundus (Pallas, 1771). Mechanical injuries in the form of scratches and skin lacerations have been observed in individuals from the study population; these may be the result of predator attacks. A condition such as ectromelia is likely to be the result of infection with trematode metacercariae. Ulcers on the skin of the limbs may be caused by infection with the fungus Batrachochytrium dendrobatidis. Digitising and saving the survey route in KML format makes it possible to carry out repeat surveys in the same area. The availability of a geospatial representation of the route enables not only the authors of this study but also other researchers to continue the research.