Acute toxicity of maneb in the tadpoles of common and green toad.

Pesticides used in agriculture can have hazardous effects on aquatic organisms, and amphibians are even more threatened than other aquatic vertebrates. Maneb is widely used to control fungal diseases on crops, fruits, and vegetables. The aim of this study was to investigate the acute toxic effects of maneb on the common (Bufo bufo) and green toad (Pseudepidalea viridis) tadpoles. Tadpoles at the development stage 21 were exposed to maneb (0-5 mg L(-1)) for 120 h. Maneb LC50 values at hour 120 were 1.966 mg L(-1) for B. bufo and 0.332 mg L-1 for P. viridis. To the best of our knowledge, these are the first published LC50 findings for the two species. Visceral oedema and tail deformations were observed in both species. We also observed liver necrosis, pronephric tubule deformations, somite deteriorations, and visceral oedema at maneb concentrations≥0.1 mg L(-1) for B. bufo and ≥0.05 mg L(-1) for P. viridis. Our results show that B. bufo tadpoles have a much higher resilience to maneb than P. viridis tadpoles. This resilience seems to be related to the larger size of the B. bufo tadpoles and their ability to metamorphose faster in adverse conditions. Future research should look into the mechanisms of toxic action of maneb in anurans.

Acute toxic effects of cadmium in larvae of the green toad, pseudepidalea variabilis (pallas, 1769) (amphibia: anura).

The environmental impact of cadmium use and its accumulation in nature have increased to alarming levels. This study aimed to morphologically and histologically investigate the acute toxic effects of cadmium on green toad, Pseudepidalea variabilis (Pallas, 1769) larvae. Embryos were obtained from specimens collected in amplexus from nature and kept under laboratory conditions until stage 26, when they were exposed to cadmium (0, 1, 5, 10, 25, and 50 Lig L⁻¹) for 96 h. The LC10 LC50, and LC90 values of cadmium were calculated to be 26.98, 35.35, and 46.31 Lig L⁻¹, respectively. Our results showed that cadmium had a negative effect on the body size of P. variabilis larvae (over 1 ng L⁻¹). Histological examination detected a fusion of gill lamellae, liver haemorrhage, oedema in the abdominal cavity, and deformations of pronephric tubules (over 10 ng L⁻¹). Our findings suggest that the green toad was sensitive to the cadmium treatment, with LC50 values lower than those reported by other studies. Thus, this species could be considered a reliable indicator species of environmental stress in aquatic ecosystem.

Genetic structuring of Anguis fragilis (L., 1758) inhabiting in the north of 40° north latitude in Turkey.

The taxonomic situation of Anguis fragilis species is still unclear in Turkey. In order to clarify this situation, we used the DNA sequences of 16S rRNA and cytochrome b genes to analyze the phylogenetic relationship among A. fragilis populations. A total of 13 haplotypes in 16S rRNA dataset and 20 haplotypes in cytochrome b dataset were detected. Kimura 2-parameter genetic distance was found to be 0.012 for 16S rRNA and 0.026 for the cytochrome b dataset. Neighbor joining (NJ) trees were constructed to analyze phylogenetic relationship among specimens and were supported with median joining networks. Results indicate a clear genetic structuring in A. fragilis populations sampled from north of 40° north latitude of Turkey. Both mitochondrial gene sequences successfully detected the intraspecific variation among specimens of different populations. Genetic structuring, correlated with geographic distance, was found to be significant at the specimens sampled from edge populations of peripherally isolated climatic conditions.

The effect of Trifolium, Raphanus, and Cistus pollen grains on some blood parameters and mesentery mast cells.

Three kinds of pollen taxa belonging to 3 families (Fabaceae--Trifolium spp., Brassicaceae--Raphanus spp. and Cistaceae--Cistus spp.) and commonly collected by honeybees were fed to mature male rats separately, in the form of 60 mg/animal/day for a 30-day period. The objective of this study was to investigate any positive effects or possible side effects of the use of pollen on the immune system. This was achieved through blood analysis and cell count on blood, hemoglobin, erythrocyte and immune system cells. The cell concentration of mast cells, degranulization and cell localization were investigated in prepared mesentery tissue samples. Histological investigations of the stomach and duedenum sections of pollen-fed rats were carried out to learn the reason for eosinophil gastroenteritis in the alimentary canal. The eosinophil and lymphocyte levels of rats fed with pollen of Trifolium spp., Raphanus spp., and Cistus spp. were observed to have increased blood cell counts, while neutrophil and monocyte levels decreased; different values were found in basophil leucocytes between the pollen groups. Differing reductions in mesentery mast cell concentration, degranulization and cell localization were found. Within the three separate pollens, the rats having been fed with Cistus spp. pollen were observed to have higher blood lymphocyte, eosinophil, hemoglobin and hematocrit values than those fed with the others, as well as low mesentery mast cell concentration. Hemoglobin values were determined to increase at a proportion of between 10.0-11.3%. No difference was found in other blood parameters. The fat proportion of the male rats fed with the three taxa was between 4.03-8.75%, while that for protein proportion was between 16.11-24.25%. Male rats receiving these taxa did not experience allergic reactions and it is possible to argue that the low protein and fat content of these pollens have a strengthening effect on the immune systems by the increase in lymphocyte content and the amount of hemoglobin leads to an increase of oxygen transport capacity in the tissues.