Survival and some physiological responses to freezing were investigated in three European water frogs (Rana lessonae, Rana ridibunda, and their hybridogen Rana esculenta). The three species exhibited different survival times during freezing (from 10 h for R. lessonae to 20 h for R. ridibunda). The time courses of percent water frozen were similar; however, because of the huge differences in bod...

Interspecies transfer of mitochondrial (mt) DNA is a common phenomenon in plants, invertebrates and vertebrates, normally linked with hybridization of closely related species in zones of sympatry or parapatry. In central Europe, in an area north of 48 degrees N latitude and between 8 degrees and 22 degrees E longitude, western Palaearctic water frogs show massive unidirectional introgression of...

Fourteen adult frogs including six banded frog, Rana camerani and eight marsh frog, Rana ridibunda ridibunda were collected from two sites of Chahar Mahal-o-Bakhtiari province at the southwest of Iran and then were examined for helminth parasites. Only Dolichosaccus rastellus  (50%) was found in R. camerani, Skrjabinoeces similis (50%) and metacercarian cysts of Codonocephalus urniger (12....

The effects of pH changes on the miniature endplate current (mepc) and on endplate current fluctuations (acetylcholine [ACh] noise) were examined at the neuromuscular junction in vitro in two species of frogs. In Rana pipiens the relationship between the decay time constant of the mepc (tau') and pH had a symmetrical bell shape; the value of tau' being largest at pH 7 and decreasing at more aci...

Fourteen adult frogs including six banded frog, Rana camerani and eight marsh frog, Rana ridibunda ridibunda were collected from two sites of Chahar Mahal-o-Bakhtiari province at the southwest of Iran and then were examined for helminth parasites. Only Dolichosaccus rastellus  (50%) was found in R. camerani, Skrjabinoeces similis (50%) and metacercarian cysts of Codonocephalus urniger (12.5%) w...

The European water frog Rana esculenta (RL), a natural hybrid between R. ridibunda (RR) and R. lessonae (LL), reproduces by hybridogenesis: haploid gametes usually contain an intact chromosome set of R. ridibunda (R); the lessonae nuclear genome (L) is lost from the germ line. Hybridity is restored in the next generation, via fertilization by syntopic R. lessonae. Matings between two hybrids (R...

European water frog hybrids Rana esculenta reproduce hemiclonally, by hybridogenesis: In the germ line they exclude the genome of the parental species Rana lessonae and produce haploid, unrecombined gametes with a genome of the parental species Rana ridibunda. These hybrids coexist with and depend as sexual parasites on the host parental species R. lessonae (the L-E population system); matings ...

the purpose of this study was to examine the acute and sub-acute effects of diazinon onhistopathological parameters of liver tissue and blood level of hepatic enzymes of male commonfrog (rana ridibunda). frogs were assigned to 9 groups (n=8, meaning 8 frogs in each group):control and treatment groups with 30, 60, 90 and 120 μg/l diazinon in water for one day or oneweek. hepatic enzymes containi...