Presence of an alien turtle accelerates hatching of common frog (Rana temporaria) tadpoles

The presence of a predator affects prey populations either by direct predation or by modifying various parts of their life history. We investigated whether the hatching time, developmental stage, and body size at hatching of common frog (Rana temporaria) embryos would be altered in the presence of a red-eared slider (Trachemys scripta elegans) as a predator. The presence of a predator affected all factors examined. We found that in the absence of the slider, the embryos hatched in 12 days, while hatching was accelerated by two days when sliders were present. At the same time, the embryos hatched smaller and at a lower stage of development with the slider than without it. Our study extends the range of predators studied, including the effect on different phases of development of potential amphibian prey.

Phenetic peculiarities of biochorological groups of different scales in a common frog (Rana temporaria linnaeus)

На примере серий лягушки травяной из четырех биотопов, характеризующихся разной степенью пространственной изоляции, показана перспективность изучения биохорологической структуры данного вида с применением фенетического подхода. Наиболее детальную характеристику пространственно-генетической структуры можно получить при анализе пятнистости дорзальной поверхности тела. Так же для этих целей возможно использование вариаций таких элементов рисунка покровов тела, как форма межлопаточного пятна и число полос на бедре. The prospects of studying the biochorological structure of the selected species using a phenetic approach are shown in a series of common frogs from four biotopes characterized by varying degrees of spatial isolation. The most detailed characterization of the spatial-genetic structure can be obtained by analyzing the spotting of the dorsal surface of the body. Also, for these purposes, it is possible to use variations of such elements of the body covering pattern as the shape of the interscapular spot and the number of stripes on the thigh.

Assessing the performance of Alphitobius piceus (Oliver, 1792) as novel feeder insect species for small sized postmetamorphic frogs

One of the major difficulties of frog farming is providing adequate food in the first few weeks after the metamorphosis. This is a critical time frame, with rapid growth and high mortality. The established feeder insect species used throughout this delicate stage (cricket and mealworm larvae, adult fruit flies) are suitable from a trophic perspective, but present challenges and difficulties that influence the production costs. The aim of this study is to assess the performance of an alternative feeder species - Alphitobius piceus - with a simpler production technology and a lower production cost. Two species of feeder insect were used: the conventionally used Acheta domestica larvae as control species, and Alphitobius piceus larvae as experimental species. As model anuran we used the European common frog, Rana temporaria. The experimental insect species was easily accepted and produced a strong feeding response in the post-metamophic frogs. There were no significant differences between the control and experimental groups in terms of body condition index and mortality, however survival was better in the experimental group. This similarity indicates a high potential of Alphitobius piceus as feeder species for the newly metamorphosed frogs and also a good economic opportunity for frog farms.

The genome sequence of the common frog, Rana temporaria Linnaeus 1758

We present a genome assembly from an individual female Rana temporaria (the common frog; Chordata; Amphibia; Anura; Ranidae). The genome sequence is 4.11 gigabases in span. The majority of the assembly is scaffolded into 13 chromosomal pseudomolecules. Gene annotation of this assembly by the NCBI Eukaryotic Genome Annotation Pipeline has identified 23,707 protein coding genes.

Present distribution of the common frog, Rana temporaria and the moor frog, R. arvalis (Amphibia, Anura) in the “old” Moscow

The common frog (Rana temporaria) and the moor frog (R. arvalis) lived in all green areas of Moscow until the end of the 20th century. The reduction in the area of woody vegetation, the destruction of breeding sites and introduction of the invasive fish Perccottus glenii contributed to the extinction of these amphibians in most of the city. The paper provides information on the distribution of brown frogs in Moscow based on the results of monitoring in 2020. R. temporaria was found in 37 localities in the Northwestern (6 points), Northern (3 points), Northeastern (1 point), Eastern (9 points), Southeastern (1 point), Southern (5 points), Southwestern (5 points) and Western (7 points) administrative districts. Eleven finds (29.7%) are located outside of specially protected natural areas. Most of the species’ habitats (30 points, or 81.1%) are isolated from other populations. R. arvalis was found in 14 localities in the Northwestern (3 points), Northern (3 points), Eastern (4 points), Southwestern (1 point) and Western (3 points) administrative districts of Moscow. Of all the finds noted, three ones (21.4%) are located outside of specially protected natural areas. The vast majority of the habitats of the species (10 points, or 71.4%) are isolated.

Ice walking common frog (Rana temporaria) (Ranidae, Amphibia)

Arecord of Rana temporaria on the ice cover of the Gulf of Finland is described. Frog slowly moved on the ice surface with speed around 0.03 m/s. Air temperature near ice surface was +3.5°C, and the frog body temperature was +4°C. In the Saint Petersburg region, common frogs can hibernate in the coastal waters of Baltic Sea with salinity of 0 – 5.8‰.

New Perspectives in the Antimicrobial Activity of the Amphibian Temporin B: Peptide Analogs Are Effective Inhibitors of Candida albicans Growth

Temporin B (TB) is a short, positively charged peptide secreted by the granular glands of the European frog Rana temporaria. While the antibacterial and antiviral efficacy of TB and some of its improved analogs are well documented, nothing is known about their antifungal potency so far. We dedicated this study to characterize the antifungal potential of the TB analog TB_KKG6K and the newly designed D-Lys_TB_KKG6K, the latter having the L-lysines replaced by the chiral counterpart D-lysines to improve its proteolytic stability. Both peptides inhibited the growth of opportunistic human pathogenic yeasts and killed planktonic and sessile cells of the most prevalent human pathogen, Candida albicans. The anti-yeast efficacy of the peptides coincided with the induction of intracellular reactive oxygen species. Their thermal, cation, pH and serum tolerance were similar, while the proteolytic stability of D-Lys_TB_KKG6K was superior to that of its template peptide. Importantly, both peptides lacked hemolytic activity and showed minimal in vitro cytotoxicity in primary human keratinocytes. The tolerance of both peptides in a reconstructed human epidermis model further supports their potential for topical application. Our results open up an exciting field of research for new anti-Candida therapeutic options based on amphibian TB analogs.