Search

The Karpathos water frog (Pelophylax cerigensis) is classified as Critically Endangered according to the IUCN Red List and its distribution is restricted on the island of Karpathos, South Aegean Sea. Utilizing a next generation sequencing approach, we obtained whole mitochondrial genomes of P. cerigensis to determine the species phylogenetic position within the genus Pelophylax and to clarify the phylogenetic relationship between the species' population on Karpathos Island and the population of P. cf. bedriagae from the neighboring Rhodes Island. High-throughput sequencing generated mean ± SD = 227 945 ± 18 306 reads averaged per sample. High quality reads were assembled resulting in the complete mitogenome of P. cerigensis of a total size of 17 922 bp. Mitogenome organization was similar to other Pelophylax species, comprising of 13 Protein Coding Genes (PCGs), 22 tRNAs, two rRNAs and one Control Region. Overall mean genetic distance for the 13 PCGs, within the Ranidae family, ranged from 8.01% (COIII) to 11.6% (ATP8), while ratios of synonymous and non-synonymous substitutions were <1 in all the 13 PCGs, indicating purifying selection. Maximum Likelihood and Bayesian Inference analyses based on the concatenated sequences of 13 PCGs and two rRNAs (12S and 16S), showed that individuals from Karpathos and Rhodes form a well-supported monophyletic group with low genetic distance between them (p-distance = 0.1%). Hence, the Rhodes populations seem to belong to P. cerigensis and not to P. bedriagae as formerly thought, highlighting the need for revision of P. cerigensis current conservation status as well as further examination of the P. bedriagae species group. [ABSTRACT FROM AUTHOR]

Geographic peculiarities of population structure and hemicloning reproduction of the water frog Pelophylax esculentus complex of 904 samples within southern East European Plain were analyzed. The proportion of populations of P. ridibundus is 0.667 against those 0.042 of P. lessonae. The RE-type populations are the most common among mixed ones (0.153). The colonies of the two parental species and P. kl. esculentus (REL-type), as well as those of P. lessonae with P. kl. esculentus (LE-type), have the frequencies 0.072 and 0.046, respectively. All-hybrid populations (E-type) are not numerous across the region (0.017). In the populations of Central, Northern and Western Ukraine, the P. lessonae genome is eliminated during gametogenesis within hybrids while in the Lower Dnieper and Lower Danube drainages, genome of P. ridibundus is eliminated. In the Eastern Ukraine populations, hybrids usually produce diploid gametes or haploid gametes with the P. ridibundus genome, less often with the chromosome set of P. lessonae only, and even more rarely a mixture of different types of gametes. The predominance of P. ridibundus in hybrid communities and the elimination of the P. lessonae genome in hybrids inevitably leads to the transformation of hybrid populations into "pure" R-type populations. This circumstance makes hybridization with P. ridibundus a factor in the shrinking of P. lessonae populations. That trend is especially expressed in the Forest steppe zone, where hybridization proceeds most intensively, the P. lessonae genome is eliminated in hybrids, and unstable populations with a numerical superiority of P. ridibundus predominate. [ABSTRACT FROM AUTHOR]

We assessed the genetic variation of 47 Moroccan populations of the North African water frog (Pelophylax saharicus) using partial sequences of the mitochondrial cytochrome oxidase subunit I gene (COI). All 239 samples belonged to the main haplotype clade previously identified from Morocco, with no haplotypes of the Algerian/Tunisian clades among our samples. Altogether 40 haplotypes were found, with a maximum of 13 mutational steps between them. Two weakly divergent haplogroups separated by a minimum of six mutational steps were distributed (i) in the Anti-Atlas and the Sahara (south of the High Atlas Mountains) versus (ii) in the Middle Atlas, the High Atlas, and in the Rif area north of the Atlas Massif. Haplotypes of the northern haplogroup were found at the southernmost locality, which might be due to human translocation, and co-occurrence of the two haplogroups was recorded at three sites within the range of the northern haplogroup. [ABSTRACT FROM AUTHOR]

The water frogs of western Tuscany (Italy) belong to the L-E hybridogenetic system, and comprise one parental species and its hybrid. A stringent morphological approach for discriminating the Italian hybrids from non-hybrids has yet to be established. In this work, using the molecular marker RrS1, we have determined the hybrid versus non-hybrid status of 43 water frogs collected from two sampling sites ("Fiume Morro Vecchio" and "Padule di Bientina"). At "Fiume Morto Vecchio" we determined 25 non-hybrids and nine hybrids and in "Padule di Bientina" we determined eight hybrids and one non-hybrid individual. All individuals of these two frog populations were analyzed morphologically. We used the derived residuals from regression analysis of all normally distributed morphological parameters on callus internus length (snout to vent length, tibia length, head width, distance nostril eye, first toe length and body mass) to build sex independent variables in discriminant analysis providing a valid contribution to morphologically distinguish hybrids from non-hybrid green frogs in Italy. [ABSTRACT FROM AUTHOR]

The great sensitivity of amphibians to land disturbance is one of the main causes that contributed to their worldwide decline. One fundamental approach in assessing amphibian ability to reflect habitat degradation is to measure their phenotypic changes in contrasting environments. We examined the extent to which several morphological traits of the endemic anuran Pelophylax perezi responded to agricultural conversion in Monegros, an arid region in NE Spain. Specifically, we determined how body size, body mass, body condition (BC) and fluctuating asymmetry (FA) of different frog classes varied among habitats with different degree of management, i.e. rice fields vs. control ponds (i.e. small reservoirs). Pelophylax perezi juveniles showed a decrease in size and mass in rice fields, revealing that early life stages are generally more susceptible to habitat alteration. Adult body condition, on the other hand, increased significantly in cultivated habitats, which apparently indicates a good fitness in this size class. Nonetheless, skeletal asymmetry of both, juveniles and adults was significantly higher in rice fields. Moreover, during postmetamorphic development FA increased significantly towards adult stage indicating that the development controlling mechanisms were not able to buffer the stress induced by land use change. Among traits, humerus, radio-ulna and metatarsal were highly sensitive in terms of expressing significant FA differences between habitats, contrary to tibio-fibula, whose precise symmetry is essential for animal locomotion. The former bones have therefore the potential to be used as sensitive indicators of stress in amphibians. FA showed no relationship with body condition. This, together with the previous results demonstrates that FA is able to capture habitat stress more reliably than the morphological estimates such as body size, mass and BC. Therefore, FA is a useful morphological tool, highly recommended to monitor stress levels in amphibian populations. [ABSTRACT FROM AUTHOR]

Central European water frog Pelophylax esculentus (formerly known as Rana esculenta) is a natural hybrid between P. lessonae and P. ridibundus. The hybrids reproduce by hybridogenesis and usually share populations with one of the parental species. Natural ridibundus-esculentus (R-E) mixed populations are rare. The population described herein is composed of 80% P. ridibundus and 20% P. esculentus represented by both sexes. We analyzed 159 adults and 228 juveniles. Age of adults collected from breeding sites ranged from 2 to 6 years in males and from 3 to 7 years in females of both taxa. The percentage of individuals older than 5 years was low. Average age of P. ridibundus was higher than that of P. esculentus. In P. ridibundus the average age of females was higher than that of males. In P. esculentus the difference between ages of females and males was not significant. Measurements of yearly radial growth of long bones revealed that the frogs grew intensively before reaching sexual maturity (3 years for females and 2 years for males). In the group of juveniles before I hibernation, P. esculentus were significantly bigger than P. ridibundus, however, there was no difference in body size between both taxa after I hibernation i.e., before the start of a new growth season. Mean LAG-1 diameters were significantly greater in adults P. ridibundus than in juveniles after I hibernation, but not in P. esculentus. [ABSTRACT FROM AUTHOR]