Pelophylax ridibundus

For the first time, including for the territory of Russian Federation, data are presented on the defensive behavior of the marsh frog Pelophylax ridibundus (Pallas, 1771) from the Republic of Mordovia and the Astrakhan region, which occurs in two variants, namely, with raising the body and protecting the eyes. The defensive behavior of the common frog Rana temporaria Linnaeus, 1758 from the Republic of Mordovia consists of covering the eyes with the fingers of the forelimbs and is encountered in the literature as “wintering”.

Three species of green frogs (Pelophylax esculentus complex) have been identified in the Khoper River Valley. The marsh frog P. ridibundus is the most widespread and found in all the studied localities. The pond frog P. lessonae and edible frog P. esculentus have been recorded only in the floodplain of the Khoper River in the Khoper State Nature Reserve (Novokhopersk district of the Voronezh region) and in the extreme northwest of the Volgograd Region.

The object of our study of the functional activity of the body's immune reactions over a long period (2021–2024) was Pelophylax ridibundus in the reservoir of an urbanized territory (Silikatnoye Lake, Nizhny Novgorod) infected with Hepatozoon spp. A hydrochemical analysis of the habitat of P. ridibundus was done. Intraerythrocyte parasites were accounted for with the calculation of the extent and intensity of invasion and abundance of hemoparasites.

Based on field surveys in 2013 – 2015 of four local populations of Bombina bombina and Pelophylax ridibundus in spawning lakes in the Medveditsa river valley (Saratov region) it was found that the body length (SVL) and weight of mature females of B. bombina and P. ridibundus ranged from 31.1 to 49.7 mm and from 63.1 to 138.1 mm; from 2.64 to 8.43 g and from 25.4 to 181.0 g, respectively.

Abnormal activity of Pelophylax ridibundus in the cooling pond of the Balakovo NPS (Saratov region) was detected during the winter period of 2003. The temperature range within which this activity was observed corresponds to that for the exit of individuals of this species from wintering during the spring period.

Molecular genetic analysis of 28 marsh frogs Pelophylax ridibundus complex from 12 localities of the Crimean peninsula was conducted by two molecular markers, namely, COI, the gene of the first subunit of cytochromeoxydase mtDNA, and SAI-1, the first intron of the serum albumin gene nDNA. It has been found that the mtDNA type specific for the “eastern” form (the Anatolian P. cf. bedriagae) prevails for the Crimean marsh frogs, while the mtDNA type of the “western” form (the Central-European P.

The size, weight and sexual structure of Pelophylax ridibundus and Bombina bombina populations was analyzed during their spawning migrations in 2013 - 2015 in four lakes of the Medveditsa River flood-plane (Saratov Region, Lysogorsky District).

The structure of the spawning anuran taxocenoses in five floodplain lakes in the Medveditsa river valley in 2009 - 2016 was analyzed. Degradation of the populations of the three most numerous species and a decreased degree of dominance of the spadefoot toad were established. This degradation strongly affects the species with a longer distance of spawning migrations - the severity of the changes sequentially decreases in the row: Pelophylax ridibundus → Pelobates fuscus → Bombina bombina.

The reproductive structure of Cosmocerca ornata (Dujardin, 1845) in marsh frogs (Pelophylax ridibundus (Pallas, 1771)) of both the striata and non-striata phenotypes was studied. Distinctions in the physiology, ecology and behavior of striped and unstriped amphibians have certain influence on the intensity of processes of the host infestation and maturing of C. ornata in frogs of different phenotypes. Analysis of the age structure of the C.