The present study describes the habitats, life cycle, larvae growth, burrowing behavior and terrestrial adaptation of Spadefoot toads in Israel based on observations and data collected during more than 30 years in nor...The present study describes the habitats, life cycle, larvae growth, burrowing behavior and terrestrial adaptation of Spadefoot toads in Israel based on observations and data collected during more than 30 years in northern Israel. The distribution area in Israel is from the north in the Upper Galilee and Golan Heights (annual rainfall range of 500 - 1000 mm) to the southern coastal plain (annual rainfall of about 250 mm). Among the 51 different breeding places of amphibians, only ponds where water was available for a few months were used by Spadefoot toads and metamorphosed populations were found around these ponds. The larvae underwent metamorphosis during the summer and autumn in northern Israel, and during the spring in central and southern Israel. A negative correlation exists between the percentage of toads burrowing and soil moisture levels, with greater burrowing behavior occurring under dry conditions. The plasma concentration increased during burrowing by electrolytes and urea accumulations. The burrowing behavior helped Spadefoot toads survive in this area at the southern border of its distribution.展开更多
A genetic study was carried out on spadefoot toads (Pelobates syriacus) from habitats of various locations and altitudes in northern Israel. Cytochrome b and 12S were amplified by PCR for the analysis of genetic varia...A genetic study was carried out on spadefoot toads (Pelobates syriacus) from habitats of various locations and altitudes in northern Israel. Cytochrome b and 12S were amplified by PCR for the analysis of genetic variation based on five DNA polymorphisms and for RAPD PCR. The nucleotide sequences of the mitochondrial DNA fragments were determined from a 460 bp clone of cytochrome b and a 380 bp clone of 12S (GenBank accession numbers, FJ595199-FJ59-5203). No genetic variation was found among the populations with regard to 12S. According to the analysis of five sequences using Arlequin software, there was a high gene identity among the populations (98.7%-99.6%). Both populations, Elrom Pond breeding site, at the highest altitude and Fara Pond, at the lowest, had the lowest identities as compared to other populations. The DNA variation among P. syri-acus populations from various breeding sites, according to band sharing (BS), when using the OP-4 primer, was 0.92-1.00. Similarity was low between the population of Elrom Pond and the populations of Kash Pond, Raihania Pond and Sasa Pond (0.92 BS), as well as between the population of Fara Pond at the lowest altitude, and the populations of Kash Pond, Raihania Pond and Sasa Pond (0.92 BS). Similar results were obtained when comparing the results obtained using primer OPA-3. The lowest similarity was found between populations of the highest altitude (Elrom Pond) and lowest altitude (Fara Pond), relative to the other ponds (Kash Pond, Raihania Pond and Sasa Pond) with a BS of 0.93.展开更多
文摘The present study describes the habitats, life cycle, larvae growth, burrowing behavior and terrestrial adaptation of Spadefoot toads in Israel based on observations and data collected during more than 30 years in northern Israel. The distribution area in Israel is from the north in the Upper Galilee and Golan Heights (annual rainfall range of 500 - 1000 mm) to the southern coastal plain (annual rainfall of about 250 mm). Among the 51 different breeding places of amphibians, only ponds where water was available for a few months were used by Spadefoot toads and metamorphosed populations were found around these ponds. The larvae underwent metamorphosis during the summer and autumn in northern Israel, and during the spring in central and southern Israel. A negative correlation exists between the percentage of toads burrowing and soil moisture levels, with greater burrowing behavior occurring under dry conditions. The plasma concentration increased during burrowing by electrolytes and urea accumulations. The burrowing behavior helped Spadefoot toads survive in this area at the southern border of its distribution.
文摘A genetic study was carried out on spadefoot toads (Pelobates syriacus) from habitats of various locations and altitudes in northern Israel. Cytochrome b and 12S were amplified by PCR for the analysis of genetic variation based on five DNA polymorphisms and for RAPD PCR. The nucleotide sequences of the mitochondrial DNA fragments were determined from a 460 bp clone of cytochrome b and a 380 bp clone of 12S (GenBank accession numbers, FJ595199-FJ59-5203). No genetic variation was found among the populations with regard to 12S. According to the analysis of five sequences using Arlequin software, there was a high gene identity among the populations (98.7%-99.6%). Both populations, Elrom Pond breeding site, at the highest altitude and Fara Pond, at the lowest, had the lowest identities as compared to other populations. The DNA variation among P. syri-acus populations from various breeding sites, according to band sharing (BS), when using the OP-4 primer, was 0.92-1.00. Similarity was low between the population of Elrom Pond and the populations of Kash Pond, Raihania Pond and Sasa Pond (0.92 BS), as well as between the population of Fara Pond at the lowest altitude, and the populations of Kash Pond, Raihania Pond and Sasa Pond (0.92 BS). Similar results were obtained when comparing the results obtained using primer OPA-3. The lowest similarity was found between populations of the highest altitude (Elrom Pond) and lowest altitude (Fara Pond), relative to the other ponds (Kash Pond, Raihania Pond and Sasa Pond) with a BS of 0.93.
