Yazar "Kulkoyluoglu, Okan" seçeneğine göre listele
Listeleniyor 1 - 9 / 9
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Assessment of rarity and ecological preferences of the non-marine ostracods (Crustacea) in Çanakkale Province (Türkiye)(Springer Basel Ag, 2024) Yavuzatmaca, Mehmet; Kulkoyluoglu, Okan; Ataman, Alper; Aytegin, Ahmet; Yilmaz, Ismail OmerRarity as a multidimensional concept has not been discussed for the ostracods along with the effects of physicochemical factors and sedimentation rates of waters on their distribution. We randomly sampled 91 aquatic sites including eight habitat types in the & Ccedil;anakkale Province to study ostracod species rarity, commonness, and ecological preferences, and to test the relationships between the rarity index (average of geographic range, habitat specificity, and population size indices) and environmental factors. A total of 44 ostracod taxa (25 living) were reported from 75 sites. Among the species, Candonocypris caledonica was recorded for the first time in T & uuml;rkiye. Sixty percent of 25 living species exhibited cosmopolitan characteristics, making significant contributions to the diversity of ostracods. The well-known cosmopolitan species, Heterocypris salina (rr = 0.268), Cypridopsis vidua (rr = 0.289), Limnocythere inopinata (rr = 0.330), Ilyocypris bradyi (rr = 0.370), and Psychrodromus olivaceus (rr = 0.390), were identified as common species based on the rarity index (rr) values. Of the environmental variables, only sediment grain sizes (x2000, x500, and x63 mu m) were found to be effective on the distribution of ostracod species. The Shannon index exhibited a positively significant association with x2000, while the population size index displayed a linear relationship with x63 mu m grain size, indicating a small population size and rarity. Associations among index values, sediment grain size, and water quality variables showed that comprehensive studies on ostracods, analyzing both water and sediment, can provide a clearer and more precise information for evaluating the rarity and ecological preferences of species.Öğe Contribution to the Freshwater Ostracoda (Crustacea) Fauna of Turkey: Distribution and Ecological Notes(Central Fisheries Research Inst, 2014) Rasouli, Hamidreza; Aygen, Cem; Kulkoyluoglu, OkanIn this study, a total of 37 freshwater ostracod species were collected from 47 stations between 31 August 2010 and 23 June 2011. Among them, three species (Eucypris kerkyrensis, Cypridopsis elongata, Bradleystrandesia parva) were new records for the Ostracoda fauna of Turkey. Bisexual populations of three species (Ilyocypris inermis, Trajancypris serrata and Psychrodromus olivaceus) were repeatedly occurred from Anatolia. Spearman Rank Correlation analyses illustrated a significant correlation for the four most abundant species (Condona neglecta, Heterocypris salina, Eucypris lilljeborgi and Potamocypris villosa) with electrical conductivity while temperature did not show a significant effect on species occurrence. Five species (Pseudocandona albicans, Ilyocypris gibba, Heterocypris incongruens, Heterocypris rotundata and Eucypris virens) did not have any significant correlation to those variables used here, but correlation was significant between Potamocypris villosa and three variables (pH, electrical conductivity and salinity). According to Environmental Tolerance Index (ETI), most species with high ETI values were widespread species. Such species with high tolerance and widespread (or cosmopolitan) distribution were named as cosmoecious speciesÖğe CONTRIBUTION TO THE OSTRACODA (CRUSTACEA) FAUNA OF THE KARSTIC REGION OF TEXAS WITH THE DESCRIPTION OF A NEW SPECIES(Natl Speleological Soc, 2023) Kulkoyluoglu, Okan; Tuncer, AlaettinA total of 27 ostracod taxa were collected from 1995 to 2017 from 61 aquatic bodies in the karstic region of Texas (USA) and 1 in Mexico, including from caves, springs, spring-fed pools, and springs/drips in karstic rock-shelters. Among these taxa, Dolerocypris reyesi sp. nov. is a new species collected from a shallow pool connected to the springs above a rock-shelter. Three species (Penthesilenula aotearoa, P. incae, and Vestalenula marmonieri) are reported for the first time from North America. In addition, Typhlocypris cf. prespica and 4 taxa (Microdarwinula zimmeri, Cypridopsis cf. herpestica, Pseudocandona cf. parallela, P. cf. pratensis) are new records of ostracod fauna of the US and Texas, respectively. The phylogenetic results based on 31 taxa and 30 morphological characters revealed 4 subgroups belonging to 6 main clustering groups within the family Darwinulidae. Including the new species reported here, the total number of non-marine ostracods in Texas is increased to 115 species. The results indicate that the total number of species is far below the true diversity and richness of the state.Öğe Description of a new species (Eucypris dorlionensis n. sp.) (Ostracoda, Crustacea) from Türkiye and a cladistic analysis of the genus Eucypris(Tubitak Scientific & Technological Research Council Turkey, 2024) Batmaz, Filiz; Kulkoyluoglu, Okan; Yavuzatmaca, MehmetThis is the first clustering analysis of the 53 species of the genus Eucypris where we used 28 plesiomorphic and apomorphic character states in the Winclada/NONA program. Accordingly, Eucypris dorlionensis n. sp. was clustered within Group 2, in which the new species was clearly separated from the other species of the genus based on the shape of the carapace, presence of fine hair -like setae on the carapace surface, the position of the maximum height of the carapace, and length ratio of terminal claws of the second antenna. Eucypris dorlionensis n. sp. was collected from a trough in Eskisehir province in Turkiye where this is the first new species description of the genus that the number of species of the genus has now increased to 10. Besides, the genus is of cosmopolitan distribution known from a variety of aquatic bodies in the world. Including the new species, the number of the species has now raised to 56.Öğe Distribution and relationships of non-marine ostracods (Crustacea, Ostracoda) with water quality variables in Amasya province (Türkiye)(Springer, 2024) Yavuzatmaca, Mehmet; Kulkoyluoglu, Okan; Ataman, Alper; Batmaz, FilizWe assessed the relationships between non-marine ostracods and water quality by collecting samples from 80 randomly selected sites between 18-22 May 2022 in the Amasya province. A total of 28 taxa (18 recent) were recorded from 59 sites, and 25 of them were new for the Amasya province. The most common species were Ilyocypris bradyi, Heterocypris incongruens, and Prionocypris zenkeri. Only 5% of the sampled sites had poor and unsuitable water status. We found ostracods in a range of water conditions, from excellent to unsuitable. Heterocypris salina, along with the most common species, was found in site 41 with unsuitable waters. The Shannon diversity index and abundance of ostracods showed non-linear relationships with the water quality index value (WQI). Although P. zenkeri did not display a linear relationship with WQI, it tended to occur in waters with increasing WQI values, indicating lower water quality. Water temperature and pH were found to be the most influential variables on species distribution, while the number of species indicated positive and negative relationships with chloride and sulphate, respectively. The functional richness values indicated that species in dams had developed swimming setae on the second antennae, while species in streams had reduced setae. The functional evenness values exposed that the functional distance between species in dams and troughs was more regular compared to streams. These results suggest that functional diversity indices can be used to evaluate the function and indicator potential of ostracod species in aquatic systems.Öğe Freshwater Ostracoda (Crustacea) of Diyarbakir Province, including a new report for Turkey(Tubitak Scientific & Technological Research Council Turkey, 2011) Akdemir, Derya; Kulkoyluoglu, OkanDuring the summer (July-August) of 2007, a total of 23 freshwater ostracods belonging to 14 genera were collected from 50 out of 90 different bodies of water in Diyarbakir. Of these 23 finds, Herpetocypris intermedia is a new report for Turkish ostracod fauna. In addition, 11 species (Ilyocypris decipiens, I. inermis, Eucypris virens, Herpetocypris brevicaudata, Psychrodromus fontinalis, Isocypris beauchampi, Potamocypris similis, P unicaudata, P arcuata, Limnocythere stationis, and L. inopinata) are reported from this city for the first time. The geographical distribution of some species is extended into the eastern parts of Turkey. Our results also suggest that species with cosmopolitan characteristics tend to have a wide distribution within a variety of habitats.Öğe Limnoecological relationships between water level fluctuations and Ostracoda (Crustacea) species composition in Lake Sunnet (Bolu, Turkey)(Tubitak Scientific & Technological Research Council Turkey, 2010) Kulkoyluoglu, Okan; Dugel, Muzaffer; Balci, Muharrem; Deveci, Aziz; Avuka, Derya; Kilic, MustafaThe ecological characteristics of ostracods in Lake Sunnet were monitored monthly between May 2005 and September 2007; 9 living and 5 subfossil ostracod taxa were recorded. Among the species, Ilyocypris getica was reported in Turkey for the first time; while Stenocypria fischeri was found for the second time in the country in 55 years. The most abundant species, Limnocythere inopinata, was collected in dry and wet months, while I. bradyi was the only species found in only the wet months. The 9 species clustered into 3 groups based on their ecological preference. Species composition and occurrences were closely related to the lake water level fluctuation, from 7 to 13 m within a year. These fluctuations played a significant role in changes in the physicochemical characteristics of the lake, along with ostracod species composition (P < 0.01). A strong negative correlation (P < 0.05) between precipitation and both ambient temperature and SO4 was also interpreted as the outcome of such fluctuations. The number of species corresponded with salinity changes. Most of the ostracod species appearing in Lake Sunnet were tolerant to the large water level fluctuation. These results correspond with the idea of 'pseudorichness,' when species composition is dominated by cosmopolitans over noncosmopolitans, an indication of low water quality in a lake. Changes in the lake have been accelerated by anthropogenic activities such as water diversions for chicken farms and agricultural fields during dry climatic conditions. The occurrence of these activities appears to have produced seasonal differences in the lake's water quality and species composition.Öğe Monthly variations in the shell structure of two freshwater ostracod (Crustacea) species in Karapinar Spring (Bolu, Turkey)(Tubitak Scientific & Technological Research Council Turkey, 2015) Kulkoyluoglu, Okan; Palacios-Fest, Manuel R.; Baron, Dirk; Sari, NecmettinThe variations of environmental conditions (T degrees C, pH, delta C-13, delta O-18, Mg/Ca, and Sr/Ca) for two ostracod species (Psychrodromus olivaceus, Potamocypris similis) were analyzed and compared to identify the controls of environmental parameters on the chemical and isotopic composition of their valves. The specimens were collected from Karapinar Spring (Bolu, Turkey) between October 2009 and November 2010. The species were observed throughout the year. Psychrodromus olivaceus showed relatively constant Mg/Ca ratios during the study period, whereas those of P. similis showed more variability. The ratio was also significantly different (P < 0.05) between the two species. We did not find significant correlation between water temperature and either of the species' Mg/Ca ratios. The stable isotope record for P. similis was very patchy, showing a small range of values consistent with the groundwater source, similar to the behavior of Sr/Ca. The Sr/Ca ratio displayed little variation throughout the year, suggesting hydrochemical stability over time, most likely in response to the groundwater source. The stable isotope data displayed pronounced variability for P. similis but little for P. olivaceus, suggesting that the former may be responding to seasonality, whereas the latter responds to groundwater.Öğe Ostracoda (Crustacea) species composition and environmental correlates in different aquatic habitats of the Zonguldak and Bartin regions (Turkey)(Tubitak Scientific & Technological Research Council Turkey, 2017) Kulkoyluoglu, Okan; Yavuzatmaca, Mehmet; Tanyeri, Meric; Yilmaz, OzanIn order to compare the ostracod species composition of the Zonguldak and Bartin regions of Turkey, samples were collected from 105 aquatic sites with 7 different habitats during June 2013. Thirteen and 18 species were identified from Bartin and Zonguldak, respectively. While all of the species are new reports for Bartin, 11 species are new for Zonguldak. Twenty-two species were common in both regions, with 40.9% similarities. Species abundance (49.2 individuals/site) was found to be greater in Zonguldak than in Bartin (33 individuals/site), but the number of species per sampling site was higher in Baron (0.48 spp./site) than in Zonguldak (0.42 spp./site). Increasing the numbers of sampling sites did not increase the numbers of species. Among the habitat types, the numbers of species per site was the lowest in troughs (0.35 spp./site). Canonical correspondence analyses explained 78.3% of the correlation with relatively low variance (9.8%) between the 15 most common species and 4 environmental variables in the regions, where water temperature (F = 3.216; P = 0.002) and electrical conductivity (F = 2.525; P = 0.018) displayed strong correlation with the species. However, water temperature per se did not show a significant effect on the numbers of species (P > 0.05). Cosmopolitan species showed relatively high tolerance and optimum values to different environmental variables.
