Theses supervised by Prof. Dr. Okan Külköylüoğlu
12 theses · Bolu Abant İzzet Baysal University
Eskişehir (Türkiye) bölgesindeki ostrakoda (Crustacea) türlerinin birlikte bulunma durumlarının ve ekolojik karakterlerinin belirlenmesi
This study aimed to understand co-occurrence patterns and ecological characteristics of ostracod species in Eskişehir province. A total of 118 sampling sites were visited and 36 ostracod species were collected from the area during 11- 17 July 2020. Twenty four of 36 species were new reports for the province. Including the previously known 20 species, numbers of ostracods are elevated to 44 species. A new species, Eucypris dorlionensis, was found in the area. The most effective ecological variables on the species occurrences were determined as elevation, nitrite, and pH from the Canonical Correspondence Analysis. Species cooccurrence showed different patterns based on habitat types in the area. Accordingly, Ilyocypris bradyi co-occurred with Herpetocypris intermedia and Prionocypris zenkeri in the all-sampling sites. Heterocypris salina and I. bradyi were generally found together in the lentic waters while P. zenkeri was found with I. bradyi in the lotic habitats. According to C2 analysis results, some species have different tolerance for ecological variables both in the lentic and lotic habitats. Indicator species analysis suggested that Heterocypris incongruens seems to prefer a wide range of artificial and lentic habitats when Ilyocypris inermis preferred lotic and natural habitats. We determined sink and source habitats based on the numbers of species per site. Distribution of ostracod species in the province was modeled with Adespatial analysis. Accordingly, 10 groups were determined in the distribution model that was created based on the distance and species richness between the sampling sites. Results suggested that cosmopolitan species with similar preferences tend to co-occur in a variety of habitats. KEYWORDS: Ostracod, Diversity, Co-occurrence, Sink and Source Habitats, Distribution
Determination of the distribution and ecological characteristics of Ostracoda (Crustacea) species in the Turkish Republic of Northern Cyprus
This study aimed to determine the distribution and ecological characteristics of Ostracoda species in the Turkish Republic of Northern Cyprus. Also, it is aimed to elaborate the species composition between the Mersin (Türkiye) and Cyprus and study the importance of the Island Biogeography Theory for ostracods reported from the islands located in the Southern and Northern hemisphere. Total of 79 sites were randomly sampled between 18 May to 12 August 2022 and 28 living ostracods from 15 different habitats were identified. Of which, 24 species are new records for the island. Calculation of the ecological tolerance and optimum values of 17 species displayed that species with cosmopolitan and/or cosmoecious characteristics had higher tolerance values for different ecological variables .The first two axes of Canonical Correspondence Analyses (CCA) explained 64.3 % of relationships between species and environmental and chemical variables. Most effective variables on the species were EC, Mg+2 and Ca+2 Ternary Plots exhibited that Na+and Cl- were dominant variables in the waters of sampling sites. A non-parametric Spearman Rank Correlation analysis outlined the correlation between eight species and nine environmental and chemical variables. The t-test result revealed that there was no significant difference between the Mersin and Cyprus. Result of this study and literature research, 256 species from Northern and 121 species from Southern hemisphere were detected with 26 common species. As a result of the evaluation of the Island Biogeography Theory, the number of species tend to increase as the island located closer to the mainland. KEYWORDS: Ostracoda, Habitat Diversity, Distribution, Ecology Preference, Tolerance and Optimum Estimates, Island Biogeography Theory
Research on the relationship between water chemistry, sediment chemistry and carapace structure of non-marine ostracoda (crustacea) from Giresun (Turkey)
This study includes 105 different freshwater habitats were sampled from Giresun during 3-8 October 2015. Nine genera and 16 species were recorded from 69 of 105 sampling sites in Giresun. All species were new record for this province. Water and sediment samples from different aquatic habitat types were collected and analyzed to show possible relationship between abundance and effects on carapace structure of Ostracoda. Selected 17 carapace sample prepared for Energy Dispersive X-ray Analysis (EDX) and the percentages of the elements forming the carapace were determined. First two axes of Canonical Correspondence Analysis (CCA) revealed 69.5% of relationship between nine species and four environmental variables. Among variables, while water temperature (P<0.05) was the most effective variable, electrical conductivity, magnesium and nitrate were less effective variables. According to C2 analysis, Heterocypris salina has maximum optimum value for water temperature. Potamocypris fallax has minimum tolerance and optimum values for electrical conductivity. Sodium in the carapace structure of H. salina was found higher than other edx samples. There was no clear evidence of relationship between calcium concentrations at water and carapace. This finding suggets that major source of calcium in carapace was sediment through water.
Malatya (Türkiye) ilindeki ostrakoda türleri üzerinde ekolojik faktörlerin belirlenmesi
This study aimed to understand ecological effective on non-marine ostracod species in Malatya. Present study includes of 125 different water bodies randomly sampled from Malatya during 3-10 August 2015. Total of 25 living non-marine species (Candona neglecta, Cyclocypris ovum, Cypria ophtalmica, Cypridopsis vidua, C. lusatica, Herpetocypris brevicaudata, H. intermedia, Heterocypris incongruens, H. rotundata, H. salina, Ilyocypris bradyi, I. brehmi, I. gibba, I. inermis, Isocypris beauchampi, Limnocythere inopinata, Potamocypris fulva, P. unicaudata, P. variegata, P. villosa, Prionocypris zenkeri, Pseudocandona albicans, Psychrodromus fontinalis, P. olivaceus, Trajancypris clavata) were recorded and 24 of them were the new report for province. The most common species was I. bradyi and it collected from 24 sampling sites from all type of habitats. C. lusatica was found the first time in Turkey. Canonical corresponded Analyses (CCA) was applied to see correlation between species and ecological variables. The first two axes of CCA explained 66.1% relationship and most effective variables were salinity, water temperature and chloride on ostracods. C2 statistical analyses was applied to determine 15 species' (with 3 or more occurrences) tolerance/optimum value for 20 variables. UPGMA analyses showed 5 clustering group within 15 species. According to the results, ostracod species with relatively wide geographical ranges tend to show wide ecological tolerance ranges corresponding to a reduction to their optimum estimates.
Determination of the relationship betweenostracoda (Crustacea) carapace size andgeographic and ecological factors indifferent aquatic habitats of Mersin (Turkey)
In the present study, total of 117 different non-marine aquatic habitats were sampled from Mersin province during 03-09 October 2015. In total, 36 species and14 sub-fossils (valves or carapace) were detected from 66 of 117 sites. 34 of the 36 species found in here are new records for the province of Mersin. In addition, four ostracod taxa (Bradleycypris cf. obliqua, Cypretta cf. reticulata, Fabeaformiscandona cf. wegelini, Hemicypris cf. largereticulata) were new record for the Turkish Ostracoda fauna. Water and sediment samples were analyzed to show the relationship between distribution of ostracod species and their valve size at different elevational ranges. Valve length of 1990 individuals which found three or more than three times were measured. The first two axes of the Canonical Corresponding Analysis (CCA) revealed 72.6% of the relationship between 12 taxa and five ecological variables. Among the variables, water temperature (P <0.05) and pH were the most effective variable whereas elevation, salinity and dissolved oxygen were less effective on the taxa. According to C2 analysis, two species Ilyocypris inermis and Potamocypris fallax showed the lowest and highest optimum values for elevation, respectively. While Psychrodromus fontinalis had a maximum tolerance for elevation, Limnocthere inopinata showed a minimum tolerance. There was a significant difference between the length of right and left valves of the individuals (P<0.05, N = 1990). In contrast, some individuals of species displayed no significant difference when some species showed variabilities among elevational ranges. Aditionally, the species P. fontinalis showed no significant result related to elevation (N=191, t=1.45, P> 0.05 ) for all the individuals wheras Ilyocypris bradyi for all the individual of this species had showed significant result (N=308, t=4.24, P < 0.001) was observed. It is clear that there is a change in valve lengths as the elevation increases, but more sampling and more measurements are required to talk about the relationship between elevation and valve length.
Adıyaman ve Burdur (Türkiye) illerindeki tatlı su ostrakodlarının (Crustacea) morfolojik ve ekolojik özelliklerinin belirlenmesi: Coğrafik dağılımlarının karşılaştırmalı analizi
In order to compare species composition of non-marine ostracods and determine their distributional patterns and ecological preferences, 241 samples were collected from Adıyaman and Burdur provinces. In Adıyaman, 26 recent and 15 sub-recent taxa were reported from 111 of 120 ramdomly selected sampling sites. All of these taxa are new records for the region. Of which, Schellencandona insueta and Gomphocythere besni n. sp were reported for first time in Turkey and later is a new in literature. In Burdur, 22 recent and 13 sub-recent taxa were recorded from 110 of 121 ramdomly selected sampling sites. 21 of them are new for Burdur. The hypothesis "Ostracod species are ramdomly distributed among sampling sites" was accepted in Adıyaman (P > 0.05) while it was rejected for Burdur and both provinces (ADIBUR). According to Index of Dispersion (S2/μ) and d-statistics, ostracod species showed clump and regular distribution in Burdur and ADIBUR, respectively. The first two axes of Canonical Correspondence Analyses (CCA) in Adıyaman, Burdur and ADIBUR explained 77.4, 84.5 and 69.7 % of relationships between species and environmental variables, respectively. According to the CCA, water temperature was found as the most effective environmental variable on species. A direct effect of regional factors (e.g., elevation) could not be seen while local factors (e.g., pH, water temperature) have an important influence on the occurrence and distribution of species. Cosmopolitan species with high tolerance levels to different environmental variables were generally found as dominant in both provinces and in different aquatic bodies. With respect to the Alpha Diversity indices values of springs, ponds and creeks, they can be considered as the source habitats for ostracods but that should be investigated and tested in future studies. Besides the difference in the quality of species and habitats in both provinces, a significant difference (P < 0.05) was found between the mean elevation and water temperatures.
Muş ve Mardin (Türkiye) illerindeki Ostrakodların (Crustacea) üreme şekilleri ile ekolojik faktörler arasındaki ilişkinin belirlenmesi
This study includes a total of 164 different water bodies randomly sampled from Mardin (65 sites) and Muş (99 sites) during 13- 20 August 2013. 78 taxa (55 living spp.) belonging to 31 genera were recorded from both provinces. Of them, 31 living species with 16 sub-fossils were found from 58 of 65 sampling sites of Mardin while 45 living with 15 sub-fossils were identified from 91 of 99 sites in Muş province. The bisexual populations of 13 taxa (Candona angulata, C. neglecta, C. sonociensis, C. lindneri, Ilyocypris gibba, I. inermis, Prionocypris zenkeri, Psychrodromus fontinalis, P. olivaceus, P. cf. robertsoni, Stenocypria fischeri, Trajancypris clavata, and Zonocypris cf. costata) were found during the study. All species were new records for both provinces. Cypretta sp. Vestalenula cf. boteai, Hemicypris inversus, H. cf. congenera, Hemicypris n. sp., bisexual populations of Trajancypris clavata and Psychrodromus cf. robertsoni are the first reports for Turkish Ostracoda fauna. The last two are also new for the literature. Total number of bisexual species increased up to 77. The first two axes of Canonical Correspondence Analyses for Mardin, Muş and both provinces explained 67.5, 74.2 and 73.3 % of relationships between species and environmental variables, respectively. The most effective variables on species were elevation, water temperature and pH. UPGMA analyses did not cluster species with different sexual mode. Ecological optimum and tolerance levels of species with different sexual mode revealed fluctuations for different variables. Specific Overlap and General Overlap indices were used on ostracods for the first time. Accordingly, there was a complete overlap for some of those environmental variables by those species (3 spp. overlap for pH; 6 spp. for dissolved oxygen, 7 spp. for water temperature, 10 spp. for electrical conductivity, 6 spp. for elevation). This means that all these species used a common utilization curves for each of these variables.
Seben taşlıyayla göleti (Bolu, Türkiye) ostrakoda (crustacea) faunasının mevsimsel dağılımı ve ekolojik özellikleri
In order to understand seasonal distribution and ecology of non-marine ostracod species, 15 stations around Seben - Taşlıyayla Lakelet (reservoir) were monthly visited between August 2013 and September 2014. Accordingly, total of eight species (Candona weltneri, Cypridopsis vidua, Herpetocypris chevreuxi, Heterocypris salina, Heterocypris incongruens, Limnocythere inopinata, Potamocypris variegata, Koencypris ornata) were reported. The most common species C. vidua collected from almost all stations showed wide ranges of dissolved oxygen (DO) (4.53-9.47 mg/L), pH (7.53-9.47), water temperature (Tw) (6-27.3 °C), total dissolved solid (TDS) (0.0235-0.1021 mg/L) and electrical conductivity (74.4-127.4 μS/cm) while H. chevreuxi, L. inopinata, H. salina, P. variegata and H. incongruens displayed the lowest TDS values. According to Ostracod Watch Model (OWM), several species exhibited a clear seasonal distribution; for example, C. vidua was common from June to December when C. weltneri was only found in March. Species richness was highest in autumn season with seven species. Regression models revealed significantly positive correlation between air and water temperature (P<0.01). Among the species, six are cosmoecious species, having high levels of tolerances to different environmental variables and with wide geographical ranges. Accordingly, the ratio between numbers of noncosmopolitan to cosmopolitan species or so called "pseudorichness ratio" was 0.33, suggesting the reservior is in the early succession stage.
Türkiye?nin Batı Karadeniz bölgesinde bulunan bazı tatlı su mağaralarının ostrakod (Crustacea) faunasının belirlenmesi
In this study nine ostracod taxa belonging to superfamily Cypridoidea were determined from 17 sampling stations of 11 caves in The Western Black Sea region. Among the taxa, eight of them (Ilyocypris bradyi, I. inermis, Candona neglecta, Ilyocypris sp., Candona sp., Psychrodromus sp. Pseudocandona sp. and Heterocypris sp.) were detected from inside and entrance of caves, but Psychrodromus olivaceus was recorded from outside of Çayırköyü cave. Unweighted Pair Group Mean Averages (UPGMA) distinguished the sites into 3 main clusters based on physical and ecological characteristics. Accordingly, about 85% of similarity were found among the sites. The species (I. bradyi, I. inermis and C. neglecta) reported in this present study shows cosmopolitan distribution. Thus, they have a chance of adaptation to cryptic conditions and can tolerate the ecological changes caused possibly by flooding events. Among all the nine taxa, living adultindividuals of I. bradyi, I. inermis and C. neglecta were reported herein for the first time from the cave environments in the literature. In addition to them, the other four taxa (Ilyocypris sp., Candona sp., Heterocypris sp., and Pseudocandona sp.) are also the new records for cave Ostracoda fauna of Turkey.Keywords: Ostracoda, cave, cosmopolitan, distribution, ecology
Ankara?nın farklı sucul alanlarında ostrakot (Crustacea) tür çeşitliliği ile çevresel değişkenler arasındaki ilişkinin belirlenmesinde kullanılan çeşitlilik hipotezlerinin karşılaştırmalı analizi
This study includes samples collected randomly from 173 different aquatic bodies from 17 counties of Ankara between 22 June and 03 July 2011. Total of 31 ostracod species were identified. When two of which (Eucypris elliptica and Cavernocypris subterranea) are new reports for the Turkish ostracod fauna, 19 taxa are new reports for Ankara region. Ecological correlation was evaluated by means of using multi-variable analyses between ostracod species and environmental variables. Canonical Correspondence Analyses (CCA) outlined 58.9 % of the correlation between species and environmental variables. Five variables (water temperature, humidity, dissolved oxygen, altitude, and atmospheric pressure) were found to be the most effective factors on species. Unweighted Paired Group Mean Analyses (UPGMA) illustrated four main clustering groups of ostracods attained in theirecological conditions. Generally, results showed that species with cosmopolitan characteristics had wide ecological tolerances for different variables. According to the Species-Area relationships, eight diversity hypotheses (passive sampling hypothesis (random placement hypothesis), island biogeography theory (area per se effect), habitat diversity hypotesis, sampling effect hypothesis, intermediate disturbance hypothesis, small island habitat hypothesis, target area hypothesis and species-energy hypothesis) were examined and compared with each other. Accordingly, results imply that habitat diversity hypothesis seems to be the most suitable hypothesis explaining ostracod distribution at different altitudinal ranges. However, results should not be generalized at the moment because of dominancy of sampling from troughs. Thus, future studies are urged to be clarify the situation.
Çubuk gölünün (Bolu, Türkiye) iklimsel ve hidrolojik değişimlerinin Ostrakoda (Crustacea) türleri ve limnoekolojik yapı üzerine etkilerinin belirlenmesi
During this study, samples were collected from 11 stations (5 being littoral and the other 6 vertical) in Lake Çubuk (Göynük, Bolu, Turkey) between July 2008 and November 2010. 17 species belonging to 10 genera (Candona neglecta, C. candida, C. sanociensis, C. weltneri, Pseudocandona albicans, P. eremita, P. semicognita, P. sucki, Fabaeformiscandona brevicornis, F. japonica, Physocypria kraepelini, Cypria ophtalmica, Ilyocypris gibba, Cypridopsis vidua, Limnocythere inopinata, Trajancypris serrata, Prionocypris zenkeri) were detected. One of them (F. japonica) was registered as a new report for the Turkish Ostracoda fauna, yet another (P. sucki) was registered for the second time. Unweighted Pair Group Mean Averages (UPGMA) of 10 species displayed clustering relationships based on ecological preferences among three groups. According to Spearman Correlation Analysis concerning 13 species and nine environmental variables, C. sanociensis showed positive relation with pH and Biological Oxygen Demand (BOD5), while C. weltneri was the only species showing negative correlation with dissolved oxygen. Canonical correspondence analysis (CCA) explained 77% (±1.74% error) of the relationship between the species and four environmental variables (temperature, electrical conductivity, turbidity and redox potantial). The overall surface area and the total volume of the lake was estimated at 16.03 hectares and 651.300 m3 on the bathymetric map. The length of the lake was 685 m, when its width was measured about 430 m during the present study. The depth of the lake reached to maximum level in spring (8.5 m) and its Secchi disc transparency was about 134.3 cm. According to sedimentation analyses, the lake accumulated 0.84 cm of sediment on average per month, while no remarkable accumulation was detected in pesticide (OCP) analyses. According to Piper diagram analyses water chemistry of the lake evolved from Ca-Mg-HCO3 water type to Na-Ca-HCO3 dominance. This result was confirmed by Principal Component Analysis (PCA). According to thermal stratification data, isogram (isopleth) results, stability analyses, stratification index (SI) and Wedderburn (W) values, Lake Çubuk appeared to be dimictic. Moreover, according to Wedderburn formulation, wind was the more efficient factor than temperature during the turnover time. Based on the average results of both Carlson Trophic State Index (CTSI) and Burns Trophic Level Index (BTLI), the lake has reached the mesotrophic level at the end of this study. It has been found out that especially the Fall Turnover, ion content and eutrophication rate were very important factors on species composition. Results indicated that swimming and cosmopolitan species were more widespread. Keywords: Ostracoda, dimictic, mesotrophic, Piper Diagram, Lake Çubuk, Bolu
Düzce ve Karabük (Türkiye) bölgesindeki ostrakoda (Crustacea) çeşitliliğinin karşılaştırmalı analizi ve ekolojik özelliklerinin belirlenmesi
During this study, 36 ostracod taxa (22 living and 14 sub-recent) were randomly collected with 4155 individuals from 81 sites in Karabük region (4,145 km2) in26 – 28 July 2012. All taxa are new reports for the region. First two axes of Canonical Correspondence Analysis (CCA) displayed 73.4% of the total inertia (6.245) of the relationship between species and environmental variables. Among the species, Heterocypris incongruens, H. salina, Ilyocypris bradyi and Psychrodromus olivaceus were found as the most frequently occurring species. When H. incongruens showed relatively higher optimum and tolerance values more than the mean values of 14 species analyzed, others showed species-specific tolerance and optimum levels. Majority of the species were mostly found from 50 troughs followed by stream, ditch, springs, ponds, lake and cave water. Results suggest that although troughs are artificial, they can provide suitable habitats for ostracods. However, converting natural water sources to troughs will eventually lower the species quality and diversity. In contrast, total of 30 ostracod taxa (19 living and 11 sub-recent) with 2738 individuals were randomly collected from 81 sites in Düzce region (2573 km²) in21-24 September, 2012. out of the individuals collected 16 species are new reports for Düzce region. First two axes of Canonical Correspondence Analysis (CCA) displayed 74% of the total inertia (5.488) for the relationship between species and environmental variables. Among the species H.salina, I.bradyi, C.neglecta, P.olivaceus were found as the most frequently occurring species when the last three species were also common in Karabük. During comparative analyses, two critical hypotheses were tested which includes: (i) numbers of species are equally distributed at the same altitudinal ranges in Düzce and Karabük that altitude alone does not effect species distribution, and (ii) no difference found in the means numbers of species between the two regions. Results showed that there was no significant difference(means numbers of species between two region) in the diversity and change in the numbers of species within the corresponding altitudinal ranges.