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    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 Omer
    Rarity 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.
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    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, Filiz
    We 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.
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    Habitat destruction in wetland affects Ostracoda (Crustacea) species occurrence patterns amid different aquatic habitats
    (SPRINGER, 2022) Külköylüoğlu, Okan; Çelikbaş, Beyza; Ataman, Alper
    To outline influence of anthropogenic activities on natural aquatic habitats such as wetlands, we sampled ostracods along with measuring several different aquatic variables at four different aquatic bodies between 2019 and 2020 in the Hidirseyhler Village (Bolu, Turkey). We found 15 living and 10 subfossil ostracods. Species with high tolerances (Eucypris virens) and/or with swimming abilities (Cypria ophtalmica) were reported from the canal and wetland. Non-swimmer ostracods (e.g., Prionocypris zenkeri) were only found from the creek. Ostracod Watch Model illustrated some species with stenochronal and eurychronal (e.g., Heterocypris incongruens) occurrences per site. CCA results displayed that water temperature and electrical conductivity were the most important explanatory variables on species. Unbiased diversity indices revealed the highest diversity in the canal followed by the creek, wetland, and trough. Wetland diversity exhibited positive and negative correlations with the canal and the creek, respectively. Tukey's pairwise test supported the significant comparisons between the trough, canal, and wetland (p < 0.01). The ratio of tolerant species per station was slightly higher in the canal than the wetland, trough, and creek. This suggests the fact that species encountered from the creek seem to be habitat specific and may be considered more vulnerable to changes in aquatic conditions. Frequency of species encountered in three habitats (wetland, canal, and trough) was significantly changed after the construction (digging and converting the wetland) activities began in August 2019. This activity was a negative impact on species diversity and richness in the wetland area where the diversity sharply dropped down and did not recover during the study. In contrast, this was probably advantage for some cosmoecious species.
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    A new genus, Tuberocandona gen. nov. (Crustacea, Ostracoda, Candonidae) and past to present ostracod species diversity in Texas (USA)
    (Int Soc Subterranean Biol, 2023) Külköylüoğlu, Okan; Ataman, Alper; Gibson, Randy; Diaz, Peter
    A new ostracod genus, Tuberocandona gen. nov., was collected from Honeycut Hollow Springs, Texas, USA Morphological comparisons and cladistic analyses showed that the new genus displays several dif-ferent features (e.g. presence of two tubercules on each of the valves, numbers of A1 segments, shape of A2 claws, shape and presence of two claw-like setae on the clasping organs, absence of d2 and dp setae on T2 and T3, absence of alpha and beta setae on Md, shape of hemipenis) from other genera of the tribe. Including the new species, the number of non-marine ostracods known from inland waters of Texas is now 118 species in 45 genera. With the aim of documenting ostracod biodiversity in Texas (USA) by including fossils, we sought documents published from 1927 to 2022 and were able to list 673 ostracod taxa belonging to 142 genera. Among the fossils, 73 ostracods were the oldest records during the Penn-sylvanian period (ca. 310 mya), while there were only 42 taxa reported from the Holocene. The Eocene had the highest number of ostracods (126 taxa). In comparison, the living species had only 18 of 673 taxa that were considered nonmarine forms. There are only six species in common with the fossils and recent records. These results suggest the potential for relatively high ostracod species richness and diversity in Texas. This is indeed strongly supported by the present study and the described new genus and its type species (Tuberocandona leonidasi sp. nov.).