Determination of ecological statuses of streams in the Ceyhan River Basin using composition and ecological characteristics of diatoms.

The present study aimed to evaluate the interactions between diatoms and ecological factors in various streams and to test the suitability of diatom indices to evaluate the ecological status of 44 streams in the Ceyhan River Basin during the spring and autumn periods of 2021 and the summer of 2022. Canonical correspondence analysis indicated the significant effects of electrical conductivity (EC), dissolved oxygen, biological oxygen demand (BOD5), total phosphorus (TP), and total nitrogen (TN) on the distribution of diatom species of streams in the Ceyhan River Basin. Of the streams, Aksu and Erkenez streams were associated with high EC, BOD5, and TP and characterized by pollution-tolerant species. Pollution-sensitive species showed close integration with Aksu Spring Brook, Gözpinar Creek, Göksun Creek, and Yesilgöz Spring Brook, which related to a high dissolved oxygen gradient. Different eco-regional diatom indices displayed different scores, representing from bad to high ecological status in the Ceyhan River basin. Among the diatom indices, Trophic Index Turkey (TIT) proved to be the more suitable metric to assess the ecological status of streams. TIT indicated deterioration of water quality in Karasu (S06), Erkenez (S07) streams, and downstream areas of the Ceyhan River and the least distributed sampling stations in the basin. Results suggested that eco-regionally developed diatom indices, like TIT, are required to more accurately assess the ecological status of streams in the Mediterranean region. The study provides a fundamental assessment of the ecological status of streams in the Ceyhan River Basin using an appropriate diatom index before the Pazarcik-centered earthquake on February 6, 2023. Findings allow someone to assess the impact of the earthquake on diatom communities and ecological factors in the region in the future studies.

Fuzzy logic as a novel approach to predict biological condition gradient of various streams in Ceyhan River Basin (Turkey).

Creating a method to categorize the ecological status of streams according to their biological conditions and establishing scientifically defensible nutrient criteria to protect their biotic integrity poses significant challenges. Biomonitoring of least disturbed areas is an important issue to accurately assess the ecological status of surface waters and ensure their sustainability. The fuzzy logic as a novel approach was firstly applied to evaluate the biological condition gradient of 44 sampled streams in the Ceyhan River Basin, utilizing two diatom indices, total phosphorus (TP), electrical conductivity (EC), and CORINE data. The fuzzy logic was employed to examine variations in the diatom compositions and land cover based on biological condition gradients (BCGs) of various streams and to assess the suitability of BCG in evaluating the health of studied stream systems. A three-layer fuzzy logic was constructed to predict BCGs of steams based on input data, with diatom metrics, TP, and EC representing BCGdia and land cover variables contributing to BCGland. The effects of operating variables were studied to optimize BCG results. The highest BCG score (0.85) was determined in Aksu Spring Brook in the spring, whereas the lowest value (0.05) was calculated in Erkenez Stream3 in the summer. BCGs showed strong relationships with nutrients, altitude, and EC. Results of BCGs indicated that sampling stations have various ecological statuses ranging from bad to high in the Ceyhan River Basin. The BCGdia and BCGland made important contributions to determine the ecological status of streams in the Ceyhan River Basin. Results showed that the BCG approach allows a more reliable way to determine the ecological status of streams in the Ceyhan River Basin by combining biological and chemical assessments for the sustainability of the environment. It is recommended that the BCG will be applied and evaluated in future research studies across various river basins, both within and outside of Turkey.

Hyporheic ostracods (Crustacea, Ostracoda) from Texas (USA) with six new species.

Between 2015 and 2017, 58 ostracod taxa were collected at 30 locations in 111 samples from the hyporheic zone of surface streams in Texas, U.S.A. Six new species (Bradleycypris foresteri n. sp., Bradleystrandesia macula n. sp., Pseudocandona lordi n. sp., Indocandona rusti n. sp., Stenocypris sancari n. sp., Cyclocypris dalyana n. sp.) are described based on carapace and soft body parts. Additionally, 17 species and two genera (Vestalenula and Indocandona) are presented as new records for Texas, and Indocandona rusti n. sp. is the first record of the genus outside India. Taxonomic positions of the new species are discussed along with ecological information. One-hundred and six nonmarine ostracod species are now reported from Texas. However, ongoing studies suggest that actual species richness is much higher.

Do Reproductive Modes and Swimming Ability Influence Occurrence of Non-Marine Ostracod (Crustacea) Species among Aquatic Habitats?

To gain a better understanding of the effect of reproductive modes and swimming ability on ostracod distribution, we visited 111 randomly selected aquatic sites in Kirsehir province. A total of 35 ostracods were newly reported for the area. The number of species with and without swimming setae was not statistically different, but numbers of sexual species was significantly lower than parthenogenetics. Species without setae did not show a significant difference between sexual and parthenogenetic forms. Numbers of species with (out) setae were not significant among different elevational ranges. Distribution of parthenogenetic species was common in all 11 habitat types when sexual species were only found from three different types located from 690 to ca. 1400 m of elevational ranges. Numbers of parthenogenetic species with or without setae did not show a difference among the ranges, but sexual species without setae exhibited wider distributional ranges (690-1289 m) than species with swimming setae (690-1089 m). Species' co-occurrence revealed two positive, five negative, and 44 random pairs of co-occurrences. Wards cluster analyses portrayed three main clustering groups. While group I includes parthenogenetic and sexual species, group II covers mostly parthenogenetic species with and without setae. Group III consists of species without setae. CCA results displayed three environmental variables (water temperature, pH and elevation) effective on species distribution. Species distributed in all elevational ranges tend to show lower optimum and wider ecological tolerances. Parthenogenetic species with swimming setae and with relatively higher tolerance ranges were dominant over sexual species. The present results suggest that swimming mode has a greater effect on species distribution among the habitats than reproductive modes.

Lacrimacandona n. gen. (Crustacea: Ostracoda: Candonidae) from the Edwards Aquifer, Texas (USA).

Lacrimacandona n. gen. with its type species Lacrimacandona wisei n. sp. from the San Marcos artesian well on the Texas State University campus (Hays County, Texas, USA) is proposed as a new genus of the subfamily Candoninae. The new species is sexually dimorphic, and so far no congeneric species have been found. The new genus has the following distinguishing characters: subtriangular carapace tapering posteriorly, uropod with a claw-like anterior seta and two short claws, one long "a" setae on male maxilliped, very large asymmetric clasping organs in males, unique shape and size of hemipenis, and unique occurrence of setae on segments.

Cypria lacrima sp. nov. A New Ostracoda (Candonidae, Crustacea) Species from Texas, U.S.A.

Okan Külköylüoglu, Derya Akdemir, Mehmet Yavuzatmaca, Benjamin F. Schwartz, and Benjamin T. Hutchins (2017) A new ostracod species, Cypria lacrima sp. nov. (Cyclocypridinae) is proposed from an artesian well in Hays County, Texas, U.S.A. The species differs from its conspecies with the following characteristics: unique shape and pit ornamentation on carapace, absence of "e" and "g" setae on both walking and cleaning legs, long gamma seta on Mandibular palp, asymmetric clasping organs and differences in the shape and size of other cheatotaxial parts. A detailed comparison among the species of the genus is provided along with ecological implications. This report increases the geographic distribution of the genus in the southern USA.

Gomphocythere besni n. sp. (Crustacea, Ostracoda) from a man-made pool (Adiyaman, Turkey).

We describe a new species (Gomphocythere besni n. sp.) from the Tavas man-made pool in Besni town (Adiyaman, Turkey). The species has several differences from its congeners in furcal structures (forked organ, seta of caudal ramus), numbers of setae on maxillula and maxillular palp, particular ornamentation with up to eight fossae in each mesh of the reticulation and in the presence of two types of lateral pore-canals (single pore opening with a sensillum and sieve plates) on the carapace. The finding of the new species extends the known geographical distribution of the living forms of the genus further to the North. The new species was found from relatively cool (16.6 ºC) and medium oxygenated waters (7.36 mg/L) in a mixture of sand and gravel substrate. Details about its ecology and taxonomic status are also compared and discussed with other species of the same genus.

Distribution of sexual and asexual Ostracoda (Crustacea) from different altitudinal ranges in the Ordu region of Turkey: testing the Rapoport Rule.

We evaluated Rapoport's rule which states a negative correlation between species richness and altitude. To understand the relationship between altitude and reproductive modes (a/sexual) of non-marine ostracods, 166 aquatic bodies in Ordu region, Turkey were randomly sampled from July 11 to July 16, 2010. A total of 26 species of ostracods were found from 133 out of 166 sites. Except for one species (Heterocypris incongruens), the other 25 species were new reports for the region. Candona improvisa was also a new report for Turkish ostracod fauna. Three species (Psychrodromus olivaceus, H. incongruens, and C. neglecta) occurred most frequently as 43, 46, and 76 times, respectively. Canonical correspondence analyses exhibited two variables [Habitat type (p=0.014; F=2.171) and water temperature (p=0.018; F=2.248)] as having the most effect on species. Correlation of species' reproductive modes to those of environmental variables measured was not significant. UPGMA dendrogram displayed 15 most frequently occurring species into four clusters where most species (11) were asexual. Although a small group (asexual species without swimming setae) showed a tendency to habitat type and electrical conductivity, such variables are believed to play secondary role on species distribution. Highest species diversity (13 species) was observed at the range of 1200 and 1400 m (a.s.l.), where numbers of stations sampled was not the highest (22). Numbers of asexual species (19) were higher than the sexual (11) but there were no significant differences (p>0.05) between the frequencies of their occurrences at different altitudinal ranges. Accordingly, our findings do not support the Rapoport Rule. Results yield that reproductive modes of species (sexual and asexual) was not directly correlated to altitude or any environmental variables measured during this study. A better explanation of ostracod diversity appears to be suitability of habitats.

An eco-friendly process: predictive modelling of copper adsorption from aqueous solution on Spirulina platensis.

The adsorption of copper ions on Spirulina platensis was studied as a function of contact time, initial metal ion concentration, and initial pH regimes. Characterization of this adsorbent was confirmed by FTIR spectrum. Modified Gompertz and Logistic models have not been previously applied for the adsorption of copper. Logistic was the best model to describe experimental kinetic data. This adsorption could be explained by the intra-particle diffusion, which was composed of more than one sorption processes. Langmuir, Freundlich, and Redlich-Peterson were fitted to equilibrium data models. According to values of error functions and correlation coefficient, the Langmuir and Redlich-Peterson models were more appropriate to describe the adsorption of copper ions on S. platensis. The monolayer maximum adsorption capacity of copper ions was determined as 67.93 mg g(-1). Results indicated that this adsorbent had a great potential for removing of copper as an eco-friendly process.

Modeling of biomass production by Spirulinaplatensis as function of phosphate concentrations and pH regimes.

Batch cultivations were performed to evaluate the influence of phosphate concentrations (0.25, 0.5, 0.75, and 1.0 g L(-1)) for pH regimes (9.5, 10.0, and 10.5) on the biomass production by Spirulina platensis. The best condition for cell growth (3.099 g L(-1)) was found at 0.5 g L(-1) phosphate and pH value of 10.0. Cultivation time, phosphate, and pH caused to increase significantly (p<0.01) in biomass production by S. platensis. Lag time was observed up to 4 h. After then, biomass production increased sharply (p<0.01) from 0.020 g L(-1) to 2.063, 2.213, 1.532, and 0.797 g L(-1) at 0.25, 0.5, 0.75, and 1.0 g L(-1) phosphate values, respectively. Modified Gompertz model could be regarded as sufficient to describe the biomass production by S. platensis with high determination coefficients and low sum of square value indicated that. Biological parameters for biomass production were successfully predicted by modified Gompertz model.

Predictive modeling of biomass production by Spirulina platensis as function of nitrate and NaCl concentrations.

Effects of nitrate (2.0, 2.5, and 3.0 g L(-1)) and salt (0.5, 1.0, 1.5, 2.0 g L(-1)) concentrations on biomass production by Spirulinaplatensis was examined in the Schlösser medium. The highest (p<0.001) biomass yields and chlorophyll a content was observed at 2.5 g L(-1) nitrate and 1.5 g L(-1) NaCl as 3.495 g L(-1) and 29.92 mg L(-1), respectively. Increment rate of biomass production was especially found between 72 and 216 h. Modified Richards, Schnute, Logistic and Gompertz models was successfully predicted (r(2)>0.96 and RSS0.003) biomass production by S.platensis as function of nitrate and salt concentrations. Low residual sum of squares (RSS) and high regression coefficients (r(2)) indicated that used models were well fitted to the experiment data and it could be regarded as sufficient to describe biomass production of Spirulina sp. Biological variables i.e. production rate (micro) and lag time (lambda) for S.platensis ranged 0.012-0.034 h(-1) and 2.43-5.85 h, respectively from biomass production were successfully predicted by modified Logistic model according to low RSS and F-testing value.