Zhivko M Zhelev - Academia.edu (original) (raw)

Papers by Zhivko M Zhelev

This study presents the reference ranges of some haematological parameters in adult specimens of ... more This study presents the reference ranges of some haematological parameters in adult specimens of Bufotes viridis from wild populations living in southern Bulgaria. All manipulations were done in laboratory conditions with live animals, 6-8 hours after their capture. In 1 mm 3 of blood, erythrocyte and leukocyte counts were estimated at 935000 for ♀ and 939210 for ♂, and 8747 for ♀ and 8813 for ♂, respectively. The measured haemoglobin level (Hb) was 13.21 g/dL and 12.33 g/dL, the haematocrit value (PCV) was 48.0% and 46.0%, respectively for females and males. The other values were as follows: mean corpuscular volume (MCV) 561.66 fL and 521.11 fL, mean corpuscular haemoglobin (MCH) 151.37 pg and 137.91 pg, mean corpuscular haemoglobin concentration (MCHC) 27.78% and 26.97%, respectively for females and males. In both sexes, the differential blood count was: lymphocytes (57%), neutrophils (15%) and low number of basophils, monocytes and eosinophils. Differences between males and females were statistically significant only relative to the haemoglobin.

Effects of pollutants on the morphological parameters of Pelophylax ridibundus populations were e... more Effects of pollutants on the morphological parameters of Pelophylax ridibundus populations were examined at two sites in southern Bulgaria: the Rice Fields Tsalapitsa (RF) and the river Vacha (Reference site, RS). Morphological analysis showed significantly different values of the index for fluctuating asymmetry (FAMI) and body condition factor (CF) in frogs from RF compared to those from RS. These findings provide information on the long-term background pollution of RF. The lower values of body CF and the high levels of FA of P. ridibundus populations from RF are considered as a consequence of the negative effects of the presence of xenobiotics in paddy cages -probably pesticides and fertilizers. The present result prove the potential for practical application of integral indicator for developmental stability, i.e. the fluctuating asymmetry in the P. ridibundus populations, in bioindication analyses for assessment of the ecological status of agroecosystems.

Basic morphological and hematological parameters were studied in adult, sexually mature individua... more Basic morphological and hematological parameters were studied in adult, sexually mature individuals of Carrasius gibelio living in two rivers with varying degrees and different types of anthropogenic pollution (less disrupted site, domestic sewage pollution and heavy metal pollution) in Southern Bulgaria. The study was conducted on 30 female fish, age 3+ from each site. The results show that in C. gibelio, which inhabit the site with heavy metal pollution, the morphological parameters BW and FCF have the lowest statistically significant values. Specimens of C. gibelio from the river site with domestic sewage pollution have the following hematological profiles: erythrocytosis, leukocytosis and hyperchromia, differential leukocyte count: neutrophilia, eosinophilia, monocytosis and lymphocytopenia. Red cell indices (MCH, MCHC and MCV) display the highest statistically significant values. The C. gibelio specimens from the site with heavy metal pollution had the following hematological profiles: erythrocytosis, leukocytopenia and hypоchromia, differential leukocyte count: neutrophilia, eosinophilia, monocytosis and lymphocytopenia. The lowest statistically significant values of red cell indices (MCH, MCHC and MCV) indicate anemic changes of microcytic and hypochromic type. The hematological parameters of C. gibelio are adequate biomarkers of the physiological state of animals and their habitats.

The purpose of this research work is to present data that show the seasonal changes (spring–summe... more The purpose of this research work is to present data that show the seasonal changes (spring–summer– autumn) of basic erythrocyte-metric parameters (ЕL: Erythrocyte length, ЕW: Erythrocyte width, ЕL/ ЕW, ES: Erythrocyte size; NL: Nucleus length, NW: Nucleus width, NL/NW; NS: Nucleus size, NS/ES: Nucleus-cytoplasmic ratio) in Pelophylax ridibundus populations from three biotopes located on two rivers in Southern Bulgaria (less disrupted biotope, with domestic sewage pollution and heavy metal pollution). Differences of high statistical significance were found among the different populations. Within the population living in conditions of domestic sewage pollution, for the entire period of the investigation the erythrocytes and their nuclei had an elliptical shape (a slight elongation of ellipses in autumn) and the biggest sizes (EL, EW, ES, NL and NS were constantly higher than the less disrupted biotope), NS/ES, became significantly smaller in autumn. Throughout the period of investigation, the values of all nine cellular and nuclear parameters were statistically-significantly the lowest in the population from the biotope with heavy metal pollution. The parameters: EL, ЕW, NL, NW and ES became significantly lower, progressively and statistically, during seasonal transitions. Cells and nuclei grew ovular in shape in comparison to the populations from the other two biotopes (this process was most pronounced in autumn) and NS/ES numbers were significantly decreased in summer and autumn.

The present work was aimed at determining the population structure of silver Prussian carp (Caras... more The present work was aimed at determining the population structure of silver Prussian carp (Carassius gibelio) populations that inhabit two anthropogenically polluted water basins from the region of the town of Galabovo (Southern Bulgaria) – the river Sazliyka (Population A) and the Rozov Kladenets reservoir (Population B). Total of 558 specimens from the river Sazliyka and 1004 specimens from the Rozov Kladenets reservoir were caught with fishing nets (cast or throw net) every month during April-October 2011. The sex composition of the C. gibelio population from the river Sazliyka was 99.64% females and 0.36% males; and the maximum age group III. In the population from the Rozov Kladenets reservoir, the sex composition was 99.30% females and 0.70% males; the maximum age group – VI. Standard length and total weight of the specimens from Population A ranged from 8.7 to 22.6 cm and 22.7 to 163.5 g. Standard length and total weight of the specimens from Population B ranged from 9.8 to 26.6 cm and 28.5 to 318.3 g. CF values in female individuals from all age groups of C. gibelio population from the river Sazliyka were statistically significantly lower than these in female individuals from the respective age groups in the population from the Rozov Kladenets reservoir.

abstract Zhelev, Zh. M., A. D. ArnAuDov and P. S. BoyADZhiev, 2015. ecological status of the Sazl... more abstract Zhelev, Zh. M., A. D. ArnAuDov and P. S. BoyADZhiev, 2015. ecological status of the Sazliyka river and its tributaries (Blatnitsa and Sokolitsa) as indicated by the color polymorphism and sexual composition of the populations Pelophylax ridibundus (Amphibia: ranidae). Bulg. J. Agric. Sci., 21: 1148–1156 The present work studies the nature of the distribution of colour polymorphism and the sexual composition (among adult, sexually mature individuals involved in the breeding process) in populations of marsh frog (Pelophylax ridibundus) inhabiting different biotopes along one of the ecologically damaged rivers in Bulgaria (the river Sazliyka) and two of its left-side tributaries (the rivers Blatnitsa and Sokolitsa). The ecological conditions and the quality of the living environment were assessed based on these two population characteristics. it was found out that in habitats located in the upper reaches of the rivers Sazliyka and Sokolitsa, in the populations of P. ridibundus the two colour morphs of the coloration of the back (striata, maculata) are equally represented. At the same time, the ratio of individuals of both sexes is close to the theoretically expected 1:1 distribution in relatively clean waters. in habitats along the middle and lower reaches of the rivers Sazliyka and Sokolitsa and the one of the river Blatnitsa, the environmental conditions are highly impaired: in the populations of P. ridibundus, the dominant morph striata is expressed. Moreover, the sex ratio has changed resulting in a predominance of the females.

The aim of this study was to investigate the integral indicator for developmental stability, the ... more The aim of this study was to investigate the integral indicator for developmental stability, the fluctuating asymmetry (FA), in the marsh frog Pelophylax ridibundus populations that inhabit biotopes of different types (running rivers and still, dam lakes), when exposed to different types of anthropogenic pollution (domestic sewage pollution and heavy metal pollution) in south Bulgaria. A total of 920 P. ridibundus individuals were used for FA analyses over three years (2009)(2010)(2011). Fluctuating asymmetry was defined by 10 morphological traits, using the index frequency of asymmetric manifestation of an individual (FAMI). In closed water basins, regardless of the nature of toxicants, the FA values in P. ridibundus populations were statistically lower than those in river populations. The FA values were constantly the highest under conditions of sustained anthropogenic pollution, with high concentrations of toxicants in rivers with domestic sewage pollution and heavy-metal pollution. The results provide better opportunities to use FA in P. ridibundus populations for bioindication and biomonitoring, and for parallel and independent analyses of the physicochemical assessment of the environmental condition.

Basic haematological parameters such as erythrocyte count, leukocyte count, haemoglobin concentra... more Basic haematological parameters such as erythrocyte count, leukocyte count, haemoglobin concentration, haematocrit value, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration, mean corpuscular volume, and differential blood formula of adults, of Pelophylax ridibundus from the Studen Kladenets Reservoir near the Lead and Zink Plant "Kardzhali" were studied. The data were compared with those of populations from biotopes with various levels of anthropogenic pollution in Southern Bulgaria. Based on the results, an evaluation of the ecological status of the Studen Kladenets Reservoir was made. The information value of the haematological parameters as bioindicators was confirmed by a general assessment of changes occurring in P. ridibundus populations from polluted biotopes, which showed specificity depending on the type and concentration of toxic agents.

abstract Zhelev, Zh. M., G. S. PoPGeorGiev and N. h. Mehterov, 2015. Changes in the hepatosomatic... more abstract Zhelev, Zh. M., G. S. PoPGeorGiev and N. h. Mehterov, 2015. Changes in the hepatosomatic index and Condition Factor in the populations of Pelophylax ridibundus (Amphibia: ranidae) from anthropogenically polluted biotopes in southern Bulgaria. Part ii. Bulg. J. Agric. Sci., 21: 534–539 the values of the hepatosomatic indexes (hiS) and the condition factor (CF) in populations of Pelophylax ridibundus living in conditions of anthropogenic pollution in Southern Bulgaria were studied and analyzed. the studied populations inhabit three biotopes: a relatively clean (control) one and two contaminated ones (domestic sewage pollution and heavy metal pollution). it was established that in individuals of both sexes in conditions of contamination the relative weight of the liver increases. in contaminated biotopes the CF values are lower in individuals of both sexes in comparison with those of the control one.

abstract Zhelev, Zh. M., G. S. PoPGeorGiev and N. h. Mehterov, 2014. Changes in the basic morphop... more abstract Zhelev, Zh. M., G. S. PoPGeorGiev and N. h. Mehterov, 2014. Changes in the basic morphophysiological parameters in the populations of Pelophylax ridibundus (Amphibia: ranidae) from anthropogenically polluted biotopes in southern Bulgaria. Part 1. Bulg. J. Agric. Sci., 20: 1202-1210 this study was conducted with the purpose to assess the condition of some vital organs (heart, spleen, kidney and gonads) of Pelophylax ridibundus populations that live in conditions of anthropogenic pollution in biotopes in southern Bulgaria, through analysing their relative weights: cardiosomatic index (CSi), spleenosomatic index (SSi), renosomatic index (rSi) and gonadоsomatic index (GSI). Populations from three biotopes were investigated: a relatively clean biotope (the control) and two polluted biotopes (with domestic sewage pollution and heavy metal pollution). We found that in both sexes, in conditions of pollution, the relative weight of the heart, spleen and kidney increased. in the population from biotope with heavy metal pollution , the relative weight of gonads was bigger.

This work presents data on the occurrence of colour polymorphism, sex ratio and age structure (am... more This work presents data on the occurrence of colour polymorphism, sex ratio and age structure (among adult individuals actually involved in the breeding process) in populations of two tailless amphibian species – Pelophylax ridibundus and Pseudepidalea viridis inhabiting anthropogenically polluted biotopes in Southern Bulgaria. The habitats are adjacent to the reservoirs " Rozov Kladenets " (pollution of household waste origin: nitrite nitrogen, suspended solids and of industrial origin: coal dust, sulfates) and " Topolnitsa " (heavy metal pollution). It was established for both biotopes with P. ridibundus populations that the individuals with the striata morph predominate in both sexes. In P. viridis populations, in the two sexes, individuals with morphs A and C predominate. In the biotope contaminated with heavy metals (the " Topolnitsa " reservoir) the female individuals predominate in both tailless amphibian populations. In both biotopes the main part of the breeding marsh frogs are of the middle age group (2+). While in the " Rozov Kladenets " reservoir the males predominate in this age group, in the " Topolnitsa " reservoir predominate the females. In animals of the senior age groups in both biotopes predominate the females (mainly of the 3+age group). In P. viridis populations in both biotopes among the breeding animals (in both sexes) predominate individuals from the 2+ and 3+ age groups. In both amphibians, animals of the age groups 4 + and 5 + are very rare (females). It was found that under bad living conditions in ponds used for reproduction, the populations of both tailless amphibians grow better in the area of the " Rozov Kladenets " reservoir.

Basic haematological parameters were studied in adult, sexually mature individuals of colour morp... more Basic haematological parameters were studied in adult, sexually mature individuals of colour morphs (striata and maculata) in the populations of Pelophylax ridibundus living in biotopes with various degrees of anthropogenic pollution (control, domestic sewage pollution and heavy metal pollution) in Southern Bulgaria. We found that in the polluted biotopes in individuals of both morphs of P. ridibundus the blood parameters: erythrocyte (RBC) and leukocyte (WBS) count, haemoglobin concentration (Hb), haematocrit (PCV) were statistically reliably higher, the number of lymphocytes (Ly) decreased, and the parameters: mean cell haemoglobin (MCH), mean cell haemoglobin concentration (MCHC), mean cell volume (MCV) and differential blood formula changed considerably in comparison with the control group. In terms of anthropogenic pollution, the average values of RBC and Hb were higher in P. ridibundus of striata morph.

Levels of fluctuating asymmetry in two species of anuran amphibians, Pelophylax ridibundus and Ps... more Levels of fluctuating asymmetry in two species of anuran amphibians, Pelophylax ridibundus and Pseudepidalea viridis, in sympatric and syntopic conditions at the dam lake "Studen Kladenets" located next to the Lead and Zinc Plant "Kardzhali", South Bulgaria, are studied. Materials were collected during the breeding season in three consecutive years.. Based on the indicators of fluctuating asymmetry in both species, grades characterizing the developmental stability of their populations are identified. These grades are indicative for the quality of the environment and are used for assessment of the biotope, carried out parallel and independently from the physicochemical analysis.

In the present work we did a bio-indicational assessment of the ecological status of the river Sa... more In the present work we did a bio-indicational assessment of the ecological status of the river Sazliyka (Southern Bulgaria) and two of its left tributaries (the rivers Blatnitsa and Sokolitsa), based on the integral indicator for the developmental stability – fluctuating asymmetry (FA) in the populations of the marsh frog Pelophylax ridibundus. Seven biotopes upstream to the mouth of the Sazliyka River, and one and four biotopes along the rivers Blatnisa and Skokolitsa, respectively, were examined. Based on the indicators for FA, grade rating was assigned, and it was also done as a characteristic of the living environment in these biotopes, parallel and independently of the data from the physicochemical analysis.

The current research examines some of the basic morphological hematological indicators (erythrocy... more The current research examines some of the basic morphological hematological indicators (erythrocyte count, leukocyte count, hemoglobin, differential blood formula) in adult, fertile species within a population of the marsh frog Pelophylax ridibundus, inhabiting two heavily polluted rivers in Bulgaria. One of the two rivers is Sazliika River, which is polluted with nitrates, phosphates, biological oxygen demand in five days and insoluble substances, and the other one is Topolnica River, polluted with heavy metals. The paper explores the use of these indicators as biological markers for the quality of the environment in the two rivers. Statistically significant differences were found between the examined parameters in the two rivers and the control group. The living in toxic conditions resulted in a single type change in the blood toxicology (increased erythrocyte count and amount of hemoglobin). The changes in the differential blood formula differ considerably – the samples from Sazliika exhibit adaptive characteristics (neutrophilia, monocytosis and lymphopenia in general leukocytosis), whereas the samples from Topolnica showed lymphopenia accompanied with neutropenia and monocytosisin general leukocytosis. This is an evidence of the degenerative effects of toxicity.

The degree of manifestation of the indicators of fluctuating asymmetry (FA) was studied in the po... more The degree of manifestation of the indicators of fluctuating asymmetry (FA) was studied in the populations of Rana ridibunda in two of the most polluted river ecosystems in Southern Bulgaria. The integral indicator of developmental stability, evaluation of the ecological condition parallel to the data of physicochemical analysis was performed. It was found that the variations in genetic homeostasis in the populations of R. ridibunda in a habitat under conditions of anthropogenic pollution occur independently on the type of toxicants, but the degree of violation expression in the form of FA depends on the nature of the pollution.

Поступила в редакцию 18.09.09 г. Размеры краснобрюхой жерлянки Bombina bombina Linnaeus, 1761 (Am... more Поступила в редакцию 18.09.09 г. Размеры краснобрюхой жерлянки Bombina bombina Linnaeus, 1761 (Amphibia, Anu-ra, Discoglossidae) у южной границы ареала вида. − Пескова Т.Ю., Желев Ж.М. − У южных границ ареала размеры тела краснобрюхой жерлянки наименьшие: на юго-западе (Болгария) максимальная длина тела 41.4 мм (самки) и 40.3 мм (самцы); на юго-востоке (За-падное Предкавказье) − 45.0 мм (самцы и самки). На юго-западе видового ареала отмечено увеличение относительной длины конечностей краснобрюхой жерлянки по сравнению с другими частями ареала. Ключевые слова: Bombina bombina, размеры тела, Болгария, Западное Предкавказье. Body size of Bombina bombina Linnaeus, 1761 (Amphibia, Anura, Discoglossidae) near its habitat's southern border. – Peskova T.Yu. and Zhelev Zh.M. – The body sizes of Bombina bombina are the least ones near the southern border of its habitat. The maximum sizes (41.4 mm, females; 40.3 mm, males) are noted on the southwest of the habitat, and 45.0 mm (females and males) are on the southeast. In the southwest of the habitat, an increase in the relative leg length of B. bombina in comparison with other parts of the habitat is noted.

Some metric parameters of the erythrocyte (big cell diameter (D-cell), small cell diameter (d-cel... more Some metric parameters of the erythrocyte (big cell diameter (D-cell), small cell diameter (d-cell), big nuclear diameter (D-nucleus) and small nuclear diameter (d-nucleus)) in the blood of Rana ridibunda, inhabiting highly developed chemical industry area, were established. The results were compared with the data from our previous work, carried out in a relatively unpolluted area and another industrial area with different kind of pollution. Considerable variations in cell and nuclear parameters were detected.

This study presents the reference ranges of some haematological parameters in adult specimens of ... more This study presents the reference ranges of some haematological parameters in adult specimens of Bufotes viridis from wild populations living in southern Bulgaria. All manipulations were done in laboratory conditions with live animals, 6-8 hours after their capture. In 1 mm 3 of blood, erythrocyte and leukocyte counts were estimated at 935000 for ♀ and 939210 for ♂, and 8747 for ♀ and 8813 for ♂, respectively. The measured haemoglobin level (Hb) was 13.21 g/dL and 12.33 g/dL, the haematocrit value (PCV) was 48.0% and 46.0%, respectively for females and males. The other values were as follows: mean corpuscular volume (MCV) 561.66 fL and 521.11 fL, mean corpuscular haemoglobin (MCH) 151.37 pg and 137.91 pg, mean corpuscular haemoglobin concentration (MCHC) 27.78% and 26.97%, respectively for females and males. In both sexes, the differential blood count was: lymphocytes (57%), neutrophils (15%) and low number of basophils, monocytes and eosinophils. Differences between males and females were statistically significant only relative to the haemoglobin.

Effects of pollutants on the morphological parameters of Pelophylax ridibundus populations were e... more Effects of pollutants on the morphological parameters of Pelophylax ridibundus populations were examined at two sites in southern Bulgaria: the Rice Fields Tsalapitsa (RF) and the river Vacha (Reference site, RS). Morphological analysis showed significantly different values of the index for fluctuating asymmetry (FAMI) and body condition factor (CF) in frogs from RF compared to those from RS. These findings provide information on the long-term background pollution of RF. The lower values of body CF and the high levels of FA of P. ridibundus populations from RF are considered as a consequence of the negative effects of the presence of xenobiotics in paddy cages -probably pesticides and fertilizers. The present result prove the potential for practical application of integral indicator for developmental stability, i.e. the fluctuating asymmetry in the P. ridibundus populations, in bioindication analyses for assessment of the ecological status of agroecosystems.

Basic morphological and hematological parameters were studied in adult, sexually mature individua... more Basic morphological and hematological parameters were studied in adult, sexually mature individuals of Carrasius gibelio living in two rivers with varying degrees and different types of anthropogenic pollution (less disrupted site, domestic sewage pollution and heavy metal pollution) in Southern Bulgaria. The study was conducted on 30 female fish, age 3+ from each site. The results show that in C. gibelio, which inhabit the site with heavy metal pollution, the morphological parameters BW and FCF have the lowest statistically significant values. Specimens of C. gibelio from the river site with domestic sewage pollution have the following hematological profiles: erythrocytosis, leukocytosis and hyperchromia, differential leukocyte count: neutrophilia, eosinophilia, monocytosis and lymphocytopenia. Red cell indices (MCH, MCHC and MCV) display the highest statistically significant values. The C. gibelio specimens from the site with heavy metal pollution had the following hematological profiles: erythrocytosis, leukocytopenia and hypоchromia, differential leukocyte count: neutrophilia, eosinophilia, monocytosis and lymphocytopenia. The lowest statistically significant values of red cell indices (MCH, MCHC and MCV) indicate anemic changes of microcytic and hypochromic type. The hematological parameters of C. gibelio are adequate biomarkers of the physiological state of animals and their habitats.

The purpose of this research work is to present data that show the seasonal changes (spring–summe... more The purpose of this research work is to present data that show the seasonal changes (spring–summer– autumn) of basic erythrocyte-metric parameters (ЕL: Erythrocyte length, ЕW: Erythrocyte width, ЕL/ ЕW, ES: Erythrocyte size; NL: Nucleus length, NW: Nucleus width, NL/NW; NS: Nucleus size, NS/ES: Nucleus-cytoplasmic ratio) in Pelophylax ridibundus populations from three biotopes located on two rivers in Southern Bulgaria (less disrupted biotope, with domestic sewage pollution and heavy metal pollution). Differences of high statistical significance were found among the different populations. Within the population living in conditions of domestic sewage pollution, for the entire period of the investigation the erythrocytes and their nuclei had an elliptical shape (a slight elongation of ellipses in autumn) and the biggest sizes (EL, EW, ES, NL and NS were constantly higher than the less disrupted biotope), NS/ES, became significantly smaller in autumn. Throughout the period of investigation, the values of all nine cellular and nuclear parameters were statistically-significantly the lowest in the population from the biotope with heavy metal pollution. The parameters: EL, ЕW, NL, NW and ES became significantly lower, progressively and statistically, during seasonal transitions. Cells and nuclei grew ovular in shape in comparison to the populations from the other two biotopes (this process was most pronounced in autumn) and NS/ES numbers were significantly decreased in summer and autumn.

The present work was aimed at determining the population structure of silver Prussian carp (Caras... more The present work was aimed at determining the population structure of silver Prussian carp (Carassius gibelio) populations that inhabit two anthropogenically polluted water basins from the region of the town of Galabovo (Southern Bulgaria) – the river Sazliyka (Population A) and the Rozov Kladenets reservoir (Population B). Total of 558 specimens from the river Sazliyka and 1004 specimens from the Rozov Kladenets reservoir were caught with fishing nets (cast or throw net) every month during April-October 2011. The sex composition of the C. gibelio population from the river Sazliyka was 99.64% females and 0.36% males; and the maximum age group III. In the population from the Rozov Kladenets reservoir, the sex composition was 99.30% females and 0.70% males; the maximum age group – VI. Standard length and total weight of the specimens from Population A ranged from 8.7 to 22.6 cm and 22.7 to 163.5 g. Standard length and total weight of the specimens from Population B ranged from 9.8 to 26.6 cm and 28.5 to 318.3 g. CF values in female individuals from all age groups of C. gibelio population from the river Sazliyka were statistically significantly lower than these in female individuals from the respective age groups in the population from the Rozov Kladenets reservoir.

abstract Zhelev, Zh. M., A. D. ArnAuDov and P. S. BoyADZhiev, 2015. ecological status of the Sazl... more abstract Zhelev, Zh. M., A. D. ArnAuDov and P. S. BoyADZhiev, 2015. ecological status of the Sazliyka river and its tributaries (Blatnitsa and Sokolitsa) as indicated by the color polymorphism and sexual composition of the populations Pelophylax ridibundus (Amphibia: ranidae). Bulg. J. Agric. Sci., 21: 1148–1156 The present work studies the nature of the distribution of colour polymorphism and the sexual composition (among adult, sexually mature individuals involved in the breeding process) in populations of marsh frog (Pelophylax ridibundus) inhabiting different biotopes along one of the ecologically damaged rivers in Bulgaria (the river Sazliyka) and two of its left-side tributaries (the rivers Blatnitsa and Sokolitsa). The ecological conditions and the quality of the living environment were assessed based on these two population characteristics. it was found out that in habitats located in the upper reaches of the rivers Sazliyka and Sokolitsa, in the populations of P. ridibundus the two colour morphs of the coloration of the back (striata, maculata) are equally represented. At the same time, the ratio of individuals of both sexes is close to the theoretically expected 1:1 distribution in relatively clean waters. in habitats along the middle and lower reaches of the rivers Sazliyka and Sokolitsa and the one of the river Blatnitsa, the environmental conditions are highly impaired: in the populations of P. ridibundus, the dominant morph striata is expressed. Moreover, the sex ratio has changed resulting in a predominance of the females.

The aim of this study was to investigate the integral indicator for developmental stability, the ... more The aim of this study was to investigate the integral indicator for developmental stability, the fluctuating asymmetry (FA), in the marsh frog Pelophylax ridibundus populations that inhabit biotopes of different types (running rivers and still, dam lakes), when exposed to different types of anthropogenic pollution (domestic sewage pollution and heavy metal pollution) in south Bulgaria. A total of 920 P. ridibundus individuals were used for FA analyses over three years (2009)(2010)(2011). Fluctuating asymmetry was defined by 10 morphological traits, using the index frequency of asymmetric manifestation of an individual (FAMI). In closed water basins, regardless of the nature of toxicants, the FA values in P. ridibundus populations were statistically lower than those in river populations. The FA values were constantly the highest under conditions of sustained anthropogenic pollution, with high concentrations of toxicants in rivers with domestic sewage pollution and heavy-metal pollution. The results provide better opportunities to use FA in P. ridibundus populations for bioindication and biomonitoring, and for parallel and independent analyses of the physicochemical assessment of the environmental condition.

Basic haematological parameters such as erythrocyte count, leukocyte count, haemoglobin concentra... more Basic haematological parameters such as erythrocyte count, leukocyte count, haemoglobin concentration, haematocrit value, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration, mean corpuscular volume, and differential blood formula of adults, of Pelophylax ridibundus from the Studen Kladenets Reservoir near the Lead and Zink Plant "Kardzhali" were studied. The data were compared with those of populations from biotopes with various levels of anthropogenic pollution in Southern Bulgaria. Based on the results, an evaluation of the ecological status of the Studen Kladenets Reservoir was made. The information value of the haematological parameters as bioindicators was confirmed by a general assessment of changes occurring in P. ridibundus populations from polluted biotopes, which showed specificity depending on the type and concentration of toxic agents.

abstract Zhelev, Zh. M., G. S. PoPGeorGiev and N. h. Mehterov, 2015. Changes in the hepatosomatic... more abstract Zhelev, Zh. M., G. S. PoPGeorGiev and N. h. Mehterov, 2015. Changes in the hepatosomatic index and Condition Factor in the populations of Pelophylax ridibundus (Amphibia: ranidae) from anthropogenically polluted biotopes in southern Bulgaria. Part ii. Bulg. J. Agric. Sci., 21: 534–539 the values of the hepatosomatic indexes (hiS) and the condition factor (CF) in populations of Pelophylax ridibundus living in conditions of anthropogenic pollution in Southern Bulgaria were studied and analyzed. the studied populations inhabit three biotopes: a relatively clean (control) one and two contaminated ones (domestic sewage pollution and heavy metal pollution). it was established that in individuals of both sexes in conditions of contamination the relative weight of the liver increases. in contaminated biotopes the CF values are lower in individuals of both sexes in comparison with those of the control one.

abstract Zhelev, Zh. M., G. S. PoPGeorGiev and N. h. Mehterov, 2014. Changes in the basic morphop... more abstract Zhelev, Zh. M., G. S. PoPGeorGiev and N. h. Mehterov, 2014. Changes in the basic morphophysiological parameters in the populations of Pelophylax ridibundus (Amphibia: ranidae) from anthropogenically polluted biotopes in southern Bulgaria. Part 1. Bulg. J. Agric. Sci., 20: 1202-1210 this study was conducted with the purpose to assess the condition of some vital organs (heart, spleen, kidney and gonads) of Pelophylax ridibundus populations that live in conditions of anthropogenic pollution in biotopes in southern Bulgaria, through analysing their relative weights: cardiosomatic index (CSi), spleenosomatic index (SSi), renosomatic index (rSi) and gonadоsomatic index (GSI). Populations from three biotopes were investigated: a relatively clean biotope (the control) and two polluted biotopes (with domestic sewage pollution and heavy metal pollution). We found that in both sexes, in conditions of pollution, the relative weight of the heart, spleen and kidney increased. in the population from biotope with heavy metal pollution , the relative weight of gonads was bigger.

This work presents data on the occurrence of colour polymorphism, sex ratio and age structure (am... more This work presents data on the occurrence of colour polymorphism, sex ratio and age structure (among adult individuals actually involved in the breeding process) in populations of two tailless amphibian species – Pelophylax ridibundus and Pseudepidalea viridis inhabiting anthropogenically polluted biotopes in Southern Bulgaria. The habitats are adjacent to the reservoirs " Rozov Kladenets " (pollution of household waste origin: nitrite nitrogen, suspended solids and of industrial origin: coal dust, sulfates) and " Topolnitsa " (heavy metal pollution). It was established for both biotopes with P. ridibundus populations that the individuals with the striata morph predominate in both sexes. In P. viridis populations, in the two sexes, individuals with morphs A and C predominate. In the biotope contaminated with heavy metals (the " Topolnitsa " reservoir) the female individuals predominate in both tailless amphibian populations. In both biotopes the main part of the breeding marsh frogs are of the middle age group (2+). While in the " Rozov Kladenets " reservoir the males predominate in this age group, in the " Topolnitsa " reservoir predominate the females. In animals of the senior age groups in both biotopes predominate the females (mainly of the 3+age group). In P. viridis populations in both biotopes among the breeding animals (in both sexes) predominate individuals from the 2+ and 3+ age groups. In both amphibians, animals of the age groups 4 + and 5 + are very rare (females). It was found that under bad living conditions in ponds used for reproduction, the populations of both tailless amphibians grow better in the area of the " Rozov Kladenets " reservoir.

Basic haematological parameters were studied in adult, sexually mature individuals of colour morp... more Basic haematological parameters were studied in adult, sexually mature individuals of colour morphs (striata and maculata) in the populations of Pelophylax ridibundus living in biotopes with various degrees of anthropogenic pollution (control, domestic sewage pollution and heavy metal pollution) in Southern Bulgaria. We found that in the polluted biotopes in individuals of both morphs of P. ridibundus the blood parameters: erythrocyte (RBC) and leukocyte (WBS) count, haemoglobin concentration (Hb), haematocrit (PCV) were statistically reliably higher, the number of lymphocytes (Ly) decreased, and the parameters: mean cell haemoglobin (MCH), mean cell haemoglobin concentration (MCHC), mean cell volume (MCV) and differential blood formula changed considerably in comparison with the control group. In terms of anthropogenic pollution, the average values of RBC and Hb were higher in P. ridibundus of striata morph.

Levels of fluctuating asymmetry in two species of anuran amphibians, Pelophylax ridibundus and Ps... more Levels of fluctuating asymmetry in two species of anuran amphibians, Pelophylax ridibundus and Pseudepidalea viridis, in sympatric and syntopic conditions at the dam lake "Studen Kladenets" located next to the Lead and Zinc Plant "Kardzhali", South Bulgaria, are studied. Materials were collected during the breeding season in three consecutive years.. Based on the indicators of fluctuating asymmetry in both species, grades characterizing the developmental stability of their populations are identified. These grades are indicative for the quality of the environment and are used for assessment of the biotope, carried out parallel and independently from the physicochemical analysis.

In the present work we did a bio-indicational assessment of the ecological status of the river Sa... more In the present work we did a bio-indicational assessment of the ecological status of the river Sazliyka (Southern Bulgaria) and two of its left tributaries (the rivers Blatnitsa and Sokolitsa), based on the integral indicator for the developmental stability – fluctuating asymmetry (FA) in the populations of the marsh frog Pelophylax ridibundus. Seven biotopes upstream to the mouth of the Sazliyka River, and one and four biotopes along the rivers Blatnisa and Skokolitsa, respectively, were examined. Based on the indicators for FA, grade rating was assigned, and it was also done as a characteristic of the living environment in these biotopes, parallel and independently of the data from the physicochemical analysis.

The current research examines some of the basic morphological hematological indicators (erythrocy... more The current research examines some of the basic morphological hematological indicators (erythrocyte count, leukocyte count, hemoglobin, differential blood formula) in adult, fertile species within a population of the marsh frog Pelophylax ridibundus, inhabiting two heavily polluted rivers in Bulgaria. One of the two rivers is Sazliika River, which is polluted with nitrates, phosphates, biological oxygen demand in five days and insoluble substances, and the other one is Topolnica River, polluted with heavy metals. The paper explores the use of these indicators as biological markers for the quality of the environment in the two rivers. Statistically significant differences were found between the examined parameters in the two rivers and the control group. The living in toxic conditions resulted in a single type change in the blood toxicology (increased erythrocyte count and amount of hemoglobin). The changes in the differential blood formula differ considerably – the samples from Sazliika exhibit adaptive characteristics (neutrophilia, monocytosis and lymphopenia in general leukocytosis), whereas the samples from Topolnica showed lymphopenia accompanied with neutropenia and monocytosisin general leukocytosis. This is an evidence of the degenerative effects of toxicity.

The degree of manifestation of the indicators of fluctuating asymmetry (FA) was studied in the po... more The degree of manifestation of the indicators of fluctuating asymmetry (FA) was studied in the populations of Rana ridibunda in two of the most polluted river ecosystems in Southern Bulgaria. The integral indicator of developmental stability, evaluation of the ecological condition parallel to the data of physicochemical analysis was performed. It was found that the variations in genetic homeostasis in the populations of R. ridibunda in a habitat under conditions of anthropogenic pollution occur independently on the type of toxicants, but the degree of violation expression in the form of FA depends on the nature of the pollution.

Поступила в редакцию 18.09.09 г. Размеры краснобрюхой жерлянки Bombina bombina Linnaeus, 1761 (Am... more Поступила в редакцию 18.09.09 г. Размеры краснобрюхой жерлянки Bombina bombina Linnaeus, 1761 (Amphibia, Anu-ra, Discoglossidae) у южной границы ареала вида. − Пескова Т.Ю., Желев Ж.М. − У южных границ ареала размеры тела краснобрюхой жерлянки наименьшие: на юго-западе (Болгария) максимальная длина тела 41.4 мм (самки) и 40.3 мм (самцы); на юго-востоке (За-падное Предкавказье) − 45.0 мм (самцы и самки). На юго-западе видового ареала отмечено увеличение относительной длины конечностей краснобрюхой жерлянки по сравнению с другими частями ареала. Ключевые слова: Bombina bombina, размеры тела, Болгария, Западное Предкавказье. Body size of Bombina bombina Linnaeus, 1761 (Amphibia, Anura, Discoglossidae) near its habitat's southern border. – Peskova T.Yu. and Zhelev Zh.M. – The body sizes of Bombina bombina are the least ones near the southern border of its habitat. The maximum sizes (41.4 mm, females; 40.3 mm, males) are noted on the southwest of the habitat, and 45.0 mm (females and males) are on the southeast. In the southwest of the habitat, an increase in the relative leg length of B. bombina in comparison with other parts of the habitat is noted.

Some metric parameters of the erythrocyte (big cell diameter (D-cell), small cell diameter (d-cel... more Some metric parameters of the erythrocyte (big cell diameter (D-cell), small cell diameter (d-cell), big nuclear diameter (D-nucleus) and small nuclear diameter (d-nucleus)) in the blood of Rana ridibunda, inhabiting highly developed chemical industry area, were established. The results were compared with the data from our previous work, carried out in a relatively unpolluted area and another industrial area with different kind of pollution. Considerable variations in cell and nuclear parameters were detected.