Heterocypris Salina Research Articles

Assessment of rarity and ecological preferences of the non-marine ostracods (Crustacea) in Çanakkale Province (Türkiye)

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 Çanakkale 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 Türkiye. 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 (×2000, ×500, and ×63 μm) were found to be effective on the distribution of ostracod species. The Shannon index exhibited a positively significant association with ×2000, while the population size index displayed a linear relationship with ×63 μm 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.

Chemical constituents of ostracod Heterocypris salina extract, anticancer and antimicrobial activity: in silico supported in vitro study

Background The majority of bioactive compounds derived from the sea have been extracted from aquatic invertebrates. While Ostracods are a diverse class of crustaceans that inhabit marine, brackish, and freshwaters, there are no available studies testing Ostracoda in the medical field. Objective The aim of this work was to produce H. salina on a large scale to evaluate its crude extract for anticancer and antimicrobial activities. Materials and methods Ostracod, Heterocypris salina was collected from its habitat in the eastern side of Lake Manzalla, Egypt, and the species was cultured in Soaba System of the National Institute of Oceanography and Fisheries (NIOF), Al-Khairia City, Egypt). Crude extract of Heterocypris salina was prepared and the extract was tested as an anticancer against different human cancer cell lines. Also, the extract was investigated as antimicrobial against different Gram-positive and Gram-negative bacteria. In addition, chemical composition of the extract by GC-MS analysis and molecular docking were also studies. Results and conclusion Ostracod Heterocypris salina was cultured, at day 50 of the culturing, about 500 L of the culturing pond was harvested using plankton to collect the biomass of H. salina. A methanol extract of H. salina was prepared and showed a moderate to good anticancer effect against liver (HepG2), lung (A549), colon (HCT), and breast (MCF7) cancer cell lines with IC50 values in the range of 12.8–23.2 µg/ml), being safe for the healthy cells of the same organs. Also, the H. salina extract showed activity against three tested Gram-negative (Escherichia coli, Klebsiella pneumonia, and Salmonella typhi) and two Gram-positive (Sarcina lutea and Bacillus cereus) bacteria. GC-MS analysis of H. salina extract revealed the presence of 11 compounds including ethyl iso-allocholate (23.1%), 9(Z)-octadecenamide, (Z)-(20.6%), oleic acid (12.3%), palmitic acid (11.65%), and α-amyrin (10.73%). Moreover, a molecular docking study was performed in order to determine the possible binding interactions of the test compounds with the essential amino acids in the binding site of thymidylate kinase (TMK).

Recent ostracods as ecological indicators and its applications: An example from the southern Tibetan Plateau

• Environmental significance of ostracods in the Yamdrok-tso basin is disclosed. • Potential of ostracods in inferring natural and anthropogenic influences is assessed. • Ostracod-based transfer functions for Ca, salinity, and alkalinity perform well. • Transfer functions for water quality status are developed for the first time. • Models for water quality status can qualitatively infer anthropogenic influences. Recent ostracods, so-called ‘modern analogues’ of ostracod fossils, are systematically correlated to the ambient environment. The reveal on the ecological response of Recent ostracods to environment variables can contribute to infer the paleolimnology or paleoclimate history based on fossil records. Here we analyzed 49 surface samples collected from the Yamdrok-tso basin in the southern Tibetan Plateau, disclosed the environmental significance of ostracods as ecological indicators, and evaluated the potential of ostracods in inferring natural and potential anthropogenic influences. The results show that ostracods including 12 species within 8 genera are extracted, i.e., one predominant species Leucocytherella sinensis , two abundant species Tonnacypris estonica and Ilyocypris bradyi , and nine less abundant species Leucocythere dorsotuberosa , Fabaeformiscandona gyirongensis , Candona candida , Heterocypris salina , I. echinata , F. caudata , Herpetocypris reptans , C. xizangensis , and Ilyocypris sp. Confronting with calcium content, salinity condition, and alkalinity of the host water, the abundant species have different optima and tolerance ranges. I. bradyi is characterized as mesotitanophilic to polytitanophilic and freshwater to α-oligohaline species adapting to low to moderate alkalinity conditions, while T. estonica is characterized as oligotitanophilic to mesotitanophilic and β-oligohaline species bearing moderate to high alkalinity condition. L. sinensis is an oligotitanophilic to mesotitanophilic and freshwater to polymixohaline species with a wide alkalinity tolerance range. Ostracods show different reaction with respect to heavy metal(loid)s. Most species are sensitive to Pb, Cu, and Ni, and resistant to Ba, As, and U. The developed transfer functions for calcium, salinity, alkalinity, and water quality status imply that it is with considerable potential to infer the natural and anthropogenic influences in the quantitative or qualitative way. Our study provides a new sight of Recent ostracods as ecological indicators and its applications, especially for the indication of water quality status at the first time, and could contribute to develop good ostracod-based proxies for paleoclimate research.

Determining effective environmental factors and ecology of non-marine Ostracoda (Crustacea) in Giresun, Turkey

To determine influential environmental factors on ostracod species, 105 aquatic sampling sites were sampled from the Giresun province. Sixteen species collected from 69 sites are new records for the study area. Seven of 16 species were found in their expected geographical distribution while two species (Ilyocypris bradyi, Psychrodromus olivaceus) showed different distribution (P < 0.05). Of which, P. olivaceus displayed a limited distribution in the northern region of the study area. Geographical distribution of some species and their co-occurrences varied among habitats. The mean values of three variables (water temperature, electrical conductivity, and elevation) were significantly different in northern region than the values of the sampling sites in the southern region (P < 0.01). Canonical Correspondence Analysis explained 72.5% of the significant relationship (P < 0.05) between species and four most effective environmental variables (water temperature, electrical conductivity, elevation, and magnesium). Heterocypris salina and Potamocypris fallax exhibited maximum and minimum tolerance (and optimum) values for electrical conductivity, respectively. Heavy metal presence on the carapace surfaces was investigated using Energy Dispersive X-ray Analysis (EDX) along with SEM photographing. The observation of metals such as copper, aluminum, silver and even radioactive element such as technetium on the carapace surfaces suggests that the organisms studied actually carry much more information about their aquatic environment than it was thought. Overall, our results support the findings of previous studies that water temperature and electrical conductivity were the two most effective factors on ostracod species and can be responsible for their distribution and occurrences in sampling area.

Heterocypris spadix sp. nov. (Crustacea: Ostracoda: Cypridoidea) from Japan, with Information on Its Reproductive Mode.

We describe the cypridoidean ostracod Heterocypris spadix sp. nov. from brackish water on Okinawa Island, Japan. The species closely resembles Heterocypris salina (Brady, 1868) but differs in that (1) the marginal infolds on valves are less developed, (2) the tubercles on the anterior margin of the right valve are completely covered by the selvage and invisible in inner view, and (3) the calcified inner lamella on the ventral margin of the left and right valves is scarcely evident in inner view, as the ventral margins of the valves bend inwardly. We determined partial sequences for the cytochrome c oxidase subunit I (COI; cox1) and 18S rRNA genes in H. spadix for future DNA barcoding and phylogenetic analyses. Our sample contained only females. A breeding experiment revealed that H. spadix females reproduce parthenogenetically. Another experiment showed that H. spadix has low tolerance to desiccation, with all individuals at 25°C dying between 1-2 hours after removal from water. We amplified and sequenced a partial 16S rRNA sequence for the endosymbiotic bacterium Cardinium from H. spadix. Infection by Cardinium may be related to the parthenogenetic reproductive mode we observed in H. spadix.

Ecological Role of Cyprideis torosa and Heterocypris salina (Crustacea, Ostracoda) in Saline Rivers of the Lake Elton Basin: Abundance, Biomass, Production, Fatty Acids.

Saline rivers are highly productive ecosystems in arid regions. The meiobenthic community (bottom meiofauna) and its dominant representatives are one of the least studied components of these aquatic ecosystems. Ostracods Cyprideis torosa and Heterocypris salina are major consumers among the species of bottom meiofauna in saline rivers flowing into the hyperhaline Lake Elton (Volgograd Region, Russia). We estimated the abundance, biomass and production of C. torosa, the dominant species at the mouth of the polyhaline Chernavka River (average salinity is ~30 g l-1), and H. salina, the dominant species at the mouth of the mesohaline Bolshaya Samoroda River (~13 g l-1), in spring (May) and summer (August). Additionally, we studied the composition and content of fatty acids of the ostracods and their potential food sources (bottom sediments with bacterial-algal mats). We found that the abundance and biomass (wet weight with shells) of C. torosa in the Chernavka River and H. salina in the Bolshaya Samoroda River reached 3.5 × 106 ind. m-2 and 117 g m-2, and 1.1 × 105 ind. m-2 and 12 g m-2, respectively. The first species formed on average about 85% of the total abundance and 96% of the total biomass of the meiobenthos, and the second one, about 13% and 31%, respectively. The daily production of C. torosa and H. salina can reach 249 and 36 mg m-2 ash-free dry weight, respectively. The results indicate that these species may play an important role in the total flow of matter and energy in the studied habitats. Based on the fatty acid (FA) composition of the ostracods and their food sources, it was found that C. torosa mainly consumed diatoms, while H. salina preferred bacteria, cyanobacteria, and green algae. Differences between the species were greater than differences between the bottom sediments from the rivers. It may mean that the ostracods selectively consumed different food items that may be related to the different nutrient requirements of the species. Seasonal changes in the FA compositions of the ostracods were higher than in their food sources (bottom sediments), which also indicates selective feeding of the species.

Effective roles of ecological factors on nonmarine Ostracoda (Crustacea) in shallow waters of Malatya (Turkey)

AbstractThis study is aimed to understand effective roles of ecological factors on nonmarine ostracods in Malatya province where 125 different aquatic bodies were randomly sampled during 3–10 August 2015. Totally, 24 of 25 species identified were new reports for the province while Cypridopsis lusatica was a new record for Turkey. The most common species Ilyocypris bradyi was collected from 12 different habitat types. Fifteen species based on their percent similarities among habitat types were clustered into five groups. The first two axes of Canonical Correspondence Analyses explained 66.1% relationship between species and environmental variables. Salinity, water temperature and chloride were found to be the most effective variables on species occurrence. Except chloride and oxidation–reduction potential, there was no significant difference in the mean numbers of environmental variables among the sampling sites with and without species (p < .05). Five most abundant species portrayed the highest ecological tolerance ranges for water temperature. Heterocypris incongruens revealed the highest optimum and tolerance range for dissolved oxygen while Heterocypris salina showed maximum ranges for salinity. Increasing numbers of sampling sites did not increase the percent species numbers per site. Species distribution varied among the habitats. Accordingly, species with swimming ability tend to inhabit more stagnant water bodies while species without such ability were found in flowing waters. This implies that species with good dispersion modes may avoid negative effects of changes in ecological conditions. Thus, our results reveal that biotic factors can also be effective on species as much as abiotic ones.

Correlational analyses of the relationships between altitude and carapace size of Ostracoda (Crustacea)

To explore the relationship between ostracods carapace (body) size and altitude, 117 non-marine aquatic habitats were sampled from Mersin province (Turkey) during 03–09 October 2015. A total of 36 species and 14 sub-fossils were detected from 66 of 117 sites located between −3 m and 1630 m a.s.l. Thirty-four of the species are previously unknown in the province. In addition, four of the taxa were new records for the Turkish Ostracoda fauna. Five species (Ilyocypris bradyi, Heterocypris salina, H. incongruens, Psychrodromus olivaceus, Potamocypris fallax) were the most common among all habitats with relatively wide ecological and altitudinal ranges. Canonical correspondence analyses revealed 72.6% of the relationship between 12 ostracods and five environmental variables. Water temperature and pH were the two most influential variables (p < 0.05) on the species. The mean length of right and left valves of the species were significantly different (p < 0.01, N = 3980) at all altitudinal ranges. A strong tendency of changes in valve height with increasing altitude seems to be more prominent (p < 0.05) than the changes in length for some species. Our results do not support some ecological rules but rather, suggest that a linear relationship between carapace size and altitude may only be applicable for some ostracods.

Holocene paleoenvironmental evolution of the Acıgöl paleo maar lake (Nevşehir, Central Anatolia)

Acigol (Nevsehir, Central Anatolia) is a drained crater lake. Acigol maar was formed by the violent vapor explosions due to the interaction of hot rhyolitic magma with the (sub-)surface water during the latest Pleistocene. A 844 cm-deep borehole was drilled at the maar and 713 cm-thick Acigol Core Succession (ACS) was retrieved. The ACS is mainly composed of lower laminated and upper non-laminated mudstones (sandy, silty, and clayey) with rare organic and volcanic interlayers. Eleven ostracod taxa (Cypris pubera, Plesiocypridopsis newtoni, Heterocypris salina, Eucypris cf. heinrichi, Candona candida, Candona meerfeldiana, Pseudocandona marchica, Cyclocypris sp., Ilyocypris bradyi, Limnocythere inopinata, and Darwinula stevensoni) were determined in this study. Along with ostracods, gastropods (Gyraulus piscinarum and Stagnicola sp.), pelecypods (Pisidium personatum), charophytes, and fish remains were also observed, while diatoms are the most frequent and abundant assemblage of the ACS. The assemblage at the lower parts of ACS mainly indicates wetter, freshwater to oligohaline, and oligotrophic and relatively deep lacustrine conditions alternating with short lake shrinkage intervals. On the other hand, the fauna at the upper part of the ACS points out to saline, shallow, and warmer lacustrine conditions.

The alwathba wetland reserve lake in Abu Dhabi, United Arab Emirates and its ostracod (seed shrimp) fauna

Al Wathba Wetland Reserve (AWWR) lake, in the United Arab Emirates (UAE), is an artificially created water body in a natural wetland region that experienced seasonal flooding before the establishment of the lake. The lake is mostly fed by treated waste water, and became a protected wetland reserve after the Greater Flamingo started to successfully breed in the area in 1998. Detailed monitoring of several hydrochemical parameters and water depth at nine stations and two inlets of treated water in the lake was conducted over a period of seven years starting in January 2010. As a result, the seed-shrimps (Ostracoda: Podocopida) Heterocypris salina , previously reported from a late Miocene location in the UAE, and Cyprinotus cingalensis were recorded for the modern fauna of the UAE for the first time. The presence of the ostracods only at the station with the lowest salinity in the AWWR Lake shows that their distribution is predominantly controlled by the salinity of the water which covered an extremely large range of more than two orders of magnitude (1.45-457%) at the different sampling sites and inlets during the monitoring period. Thus, the lake represents an interesting and important ecological research laboratory under semi-natural conditions.

Morphological re-description and molecular characterization of Heterocypris salina (Brady, 1868), a new recorded ostracod species in Egypt.

Morphological re-description and molecular characterization of Heterocypris salina (Brady, 1868), a new recorded ostracod species in Egypt.

Holocene Ostracoda (Crustacea) from the shallow Lake Vrana (Dalmatia, Croatia) and their paleoenvironmental significance

Lake Vrana in Dalmatia is a coastal karstic brackish water environment characterized by a high species richness of ostracods that evolved into their current morphologies during the Holocene. The results of this study reveal five ostracod zones within an 11 m sediment core taken from the central part of the lake. This sedimentary sequence reveals significant changes in both depositional and environmental conditions at local and regional scales; the oldest freshwater deposits, interpreted as the Late Pleistocene/Holocene transition, mainly comprise the species Candona neglecta, Juxilyocypris cf. schwarzbachi, Hungarocypris madaraszi, Darwinula stevensoni, and Mixtacandona sp. Although the lake had not formed at this time, it is well known that the living environment of most ostracod species is connected to flooded plains, marshes, rivers, springs, and interstitial waters. In the deepest and oldest sediments within the core, from depths between 1101 cm and 945 cm, the presence of C. neglecta and J. cf. schwarzbachi are indicative of cold water, while the dominant taxa at depths between 945 cm and 874 cm are the brackish species Cyprideis torosa and C. angulata, possibly suggesting the influence of seawater because of the presence of a permeable karstic ridge that separates the lake from the ocean. In contrast, the dominant ostracod taxa at depths between 874 cm and 813 cm are species typical of freshwater environments subject to colder climatic conditions indicating a marshy, low-energy wetland. We know that the first permanent freshwater body formed at about 8130 cal yr BP (a depth of 813 cm), while large proportions of Pseudocandona marchica, Heterocypris salina, D. stevensoni, and Metacypris cordata are all indicative of warmer, shallow waters that are rich in vegetation and have variable water level. Similarly, from 5240 cal yr BP onwards, a marine influence within the core is evidenced by the presence of Cy. torosa, while present lake water conditions (i.e., alternating seasonal changes in salinity from freshwater to brackish) were established by 2750 cal yr BP. The ostracod assemblages in sediments from Lake Vrana in Dalmatia have significant potential for reconstructing the evolution of this lake as well as for understanding environmental changes and rising sea level.

Ecological classification of the freshwater Ostracoda (Crustacea) based on physicochemical properties of waters and habitat preferences

The relationship between ecological characteristic of freshwater ostracods and their habitat preferences has been a critical issue for understanding of both current and past aquatic conditions. To evaluate this idea, 121 water bodies with 11 different habitat types were randomly sampled in the province of Kütahya. Water quality measurements indicated high to low (Ca2+ > Mg2+ > Na+) cations and relatively low (SO42− > Cl− > F−) anion concentrations with Ca2+ being the dominant ion. Sixteen of 23 species were new reports for the area. Alpha diversity (H′ = 3.64) was found relatively high. Four most abundant species with ca. 93% of similarities contributed highest alpha values in warm to cooler (lower than 25 °C), alkaline (pH 8.22), and fresh to slightly brackish waters. Heterocypris salina and Ilyocypris bradyi also revealed the highest tolerances for electrical conductivity. Based on habitat type, species were clustered into three main groups (I–III). Canonical Correspondence Analyses explained about 57.4% of correlation between species and environmental variables. Redox potential, pH, water temperature and electrical conductivity were found to be the most effective factors on species occurrences while habitat type and dissolved oxygen were not effective. Total number of species showed strong negative and positive relationships with water temperature and dissolved oxygen, respectively. Results clearly showed that cosmopolitan species exhibited relatively wide tolerance ranges to different environmental variables. Accordingly, having wide tolerance ranges seems to provide advantages to cosmopolitan species, increasing their survival chances in a variety of habitats.

Ostracoda Assemblages and Palaeoenvironmental Characteristics of the Soma Formation (Late Miocene-Pliocene), İvrindi - NW Balıkesir, Turkey

In the present study, a non-marine ostracods assemblage was defined from the Upper Miocene-Pliocene Soma Formation cropping out İvrindi (NW Balıkesir). The Soma Formation composed mainly of clayey limestone, marl, tuffite, sandstone and conglomerate in the study area. Fourteen of 22 samples collected from the measured section have ostracod fossils and six species belonging to five genera have been identified in the area. These ostracod species are Cyprideis torosa, Cyprideis pannonica, Heterocypris salina, Heterocypris sp, Ilyocypris sp and Limnocythere sp. In general, species richness, diversity and preservation of the ostracod assemblages were poor throughout the section. The brackish water species Cyprideis were dominantly found at the lower level of the section, while Ilyocypris species, which generally survive in river mouths and can also live in oligohaline environments as well as slightly brackish water, was detected at the middle and upper levels of the section. These fossil assemblages suggest that in the study area, the bottom sequences of the Soma Formation were deposited under brackish water environment and changed to limnic condition at the upper levels during late Miocene-Pliocene.

Ecology and distribution of living ostracod assemblages in a shallow endorheic lake: the example of the Lake Trasimeno (Umbria, central Italy)

<p>Ostracod assemblages from Lake Trasimeno (Umbria, central Italy), the largest endorheic lake in Italy, were investigated relating their species distribution and ecology to modern physical, chemical and biological parameters. Nineteen living species were collected in the lake<em> </em>(<em>Darwinula stevensoni, Candona (Candona) candida, Candona (Neglecandona) angulata, Fabaeformiscandona fabaeformis, Pseudocandona marchica, Cypria ophtalmica, Ilyocypris gibba, I. salebrosa, I. getica, Cypridopsis vidua, Eucypris virens, Trajancypris clavata, Herpetocypris helenae, Heterocypris salina, H. incongruens, Isocypris beauchampi, Cyprideis torosa, Limnocythere inopinata, </em>and<em> </em><em>L. stationis</em>)<em>. </em>All the identified species belong to the fresh-water Italian ostracod fauna but<em> </em><em>Cyprideis</em> <em>torosa </em>is documented in an oligohaline athalassic lacustrine environment in Italy for the first time.<em> </em>The occurrence of<em> </em><em>Ilyocypris</em> <em>salebrosa </em>represents the southernmost record in Italy and the westernmost in Eurasia. The recovery of<em> </em><em>Limnocythere</em> <em>stationis</em> represents the westernmost record in Eurasia. The distribution of the different ostracods recovered in Lake Trasimeno is linked to the dominant physical and chemical parameters for each ecological niche. Physical and chemical data along with substratum type, grain-size and presence of aquatic macrophytes have been related to different ostracods using a multivariate analyses approach (NMDS, CCA, Spearman’s rank correlation test). These results allow to differentiate several ecological niches within the lake and indicate that the main parameters affecting the ostracod assemblages are the aquatic macrophyte coverage, the Total Organic Carbon (TOC) and, to a lesser extent, temperature and type of substrate.<em> </em><em>Cyprideis</em> <em>torosa </em>and<em> </em><em>Candona </em>(<em>Neglecandona</em>)<em> </em><em>angulata </em>have been recovered both in the distal part of the lake and in the lakeshore area. In both cases they are associated with scarce or absent aquatic macrophytes and low amounts of TOC. The<em> </em>alternate dominance of these two species in the distal deeper assemblages seems to be mainly linked with the bottom oxygen availability, being<em> </em><em>C.(N.) angulata </em>dominant in the most oxygen-depleted sediments and<em> </em><em>C. torosa </em>dominant in higher oxygen conditions.<em> </em>Along the lakeshore area they are often discovered together with other prevailing species, such as<em> </em><em>Cypridopsis</em> <em>vidua </em>that is common in very shallow to shallow<em> </em>(20-140 cm) sites with high TOC content, abundant macrophytes and algae, and Limnocythere inopinata, which dominates slightly deeper areas (around 150-210 cm) where the previous species are almost absent. The Spearman’s rank correlation test showed significant positive correlation between some ostracods and macrophyte species.</p>

Spatial distribution and ecology of the Recent Ostracoda from Tangra Yumco and adjacent waters on the southern Tibetan Plateau: A key to palaeoenvironmental reconstruction

• Distribution and ecology of modern freshwater ostracods from a remote region, Tibetan Plateau. • Ecology of living ostracods from extremely high altitudes freshwater ecosystems. • Contribution to biodiversity and taxonomy of Tibetan Recent ostracods. • Baseline data for palaeolimnological investigations using Tibetan ostracods. We elucidate the ecology of Recent Ostracoda from a deep brackish lake, Tangra Yumco (30°45′—31°22′N and 86°23′—86°49′E, 4595 m a.s.l.) and adjacent waters on the southern Tibetan Plateau. Ostracod associations (living and empty valves) in sixty-six sediment samples collected from diverse aquatic habitats (lakes, estuary-like water and lagoon-like water waters, rivers, ponds and springs) were quantitatively assessed. Eleven Recent Ostracoda were found (nine living and two as empty valves only). Cluster analysis established two significant (p < 0.05) habitat specific associations; (i) Leucocytherella sinensis , Limnocythere inopinata , Leucocythere ? dorsotuberosa , Fabaeformiscandona gyirongensis and Candona xizangensis are lacustrine fauna . (ii) Tonnacypris gyirongensis , Candona candida , Ilyocypris sp., Heterocypris incongruens and Heterocypris salina are temporary water species . Ostracod distribution and abundance are significantly (p < 0.05) correlated to physico-chemical variables. The first two axes of a canonical correspondence analysis (CCA) explain 30.9% of the variation in the species abundance data. Conductivity and habitat types are the most influential ecological factors explaining the presence and abundance of ostracods. Spearman correlation analysis reveals that: (i) Two species, L .? dorsotuberosa (r = 0.25) and L. inopinata (r = 0.36) have a significant positive correlation with conductivity while one species, T. gyirongensis (r = −0.68) displays a significant negative correlation with conductivity. Limnocythere inopinata correlates significantly positive (r = 0.37) with alkalinity. Fabaeformiscandona gyirongensis correlates significantly positive (r = 0.28) with water depth. Key indicator living assemblages are: (i) L . sinensis dominates Ca-depleted brackish waters although ubiquitously distributed; (ii) L. ? dorsotuberosa dwells in fresh to brackish waters; (iii) L . inopinata predominates in mesohaline to polyhaline waters; (iv) F. gyirongensis inhabits exclusively brackish-lacustrine deeper waters; (v) C . candida populates freshwaters; (vi) T . gyirongensis and Ilyocypris sp. are restricted to shallow temporary waters; (vii) H . incongruens occurs in ponds. Water depth indicators are F . gyirongensis and L.? dorsotuberosa , useful in ostracod assemblages for palaeo-water depth reconstruction. Our results expand the knowledge of the ecological significance of Recent Tibetan Ostracoda ecology. This is a new insight on habitat chacteristics of both living assemblages and sub-Recent associations of ostracods in mountain aquatic ecosystems. The new modern ostracod dataset can be used for the quantitative reconstruction of past environmental variables (e.g., conductivity) and types of water environment. The key indicator ostracods are relevant in palaeolimnological and climate research on the Tibetan Plateau.

The spring of Nadaouiyeh Aïn Askar — Paleoecology of a Paleolithic oasis in arid central Syria

The site Nadaouiyeh Aïn Askar, an ancient artesian spring near the village of El Kowm, Central Syria, is an example of long lasting human occupation in a desert environment throughout the Middle and Late Pleistocene. The excavations expose a succession of sedimentary units, containing an artifact assemblage assigned to the Acheulean techno-complex. Unit VI, attributed to the Marine Isotope Stage 13, is rich in ostracod valves and was chosen for the present environmental study. From these sediments Heterocypris salina, H. incongruens, Cyprideis torosa, Ilyocypris cf. bradyi, I. inermis, I. cf. gibba, Darwinula stevensoni, Plesiocypridopsis newtoni, Pseudocandona compressa, Candona cf. neglecta, Pseudocandona sp., Trajancypris sp., Physocypria sp. and Mixtacandona sp. are documented for the first time in the Middle Pleistocene of the arid environment of central Syria. Data from these microfossils as well as geochemical proxies implicate three phases, turning the wetland from a palustrine setting into a spring supplied pond with increasing salinity. The high mineralization of the spring waters enables a discussion about early hominin adaptability to brackish waters as drinking water resources, common within the steppe and desert environments along the “out-of-Africa”—corridor in the eastern Mediterranean.

Living and Dead Ostracod Assemblages in a Coastal Mediterranean Wetland

The Mediterranean coast holds a wide and rich variety of wetlands, some of which are protected by international laws, but at the same time have been historically subjected to threatening activities such as agriculture, pollution and aquifer overexploitation. As part of a conservation and restoration project at the Marjal dels Moros coastal wetland (Eastern Iberian Peninsula) we initiated investigations to begin to characterise aquatic environments, and evaluate changes in the system experienced in recent times. To this aim, we collected four seasonal samples at seven points of the Marjal dels Moros wetland, varying in salinity, permanence and other environmental conditions, and studied the recent past (early modern to contemporary remains) and present (living) communities of Ostracoda. We found relatively poor species richness overall, possibly related to the brackish and seasonal character of large parts of the wetland. Of the seven species encountered the most common ostracods were tolerant to these stressing conditions: Heterocypris salina, Sarscypridopsis aculeata, Ilyocypris gibba and Cypridopsis vidua. A comparison of dead and living assemblages showed no significant differences, suggesting that the overall ostracod metacommunity was resilient to the perturbations experienced in the area, despite some particular locations recording notable shifts in their communities during the sampling period.

Palaeoenvironmental inferences from late Quaternary sediments of the Al Jafr Basin, Jordan

Sedimentological, palaeontological and mineralogical analyses of sediments from the endorheic Al Jafr Basin were conducted to better understand the depositional and hydrological conditions on the southern Jordan Plateau in the late Quaternary. Surficially exposed carbonate-rich sediments in the western part of the basin contain ostracod (micro-crustacean) shells of Ilyocypris cf. bradyi, Candona neglecta, Heterocypris salina, Fabaeformiscandona fabaeformis, Pseudocandona sp. and Herpetocypris brevicaudata. The shells of these and other more rare species, and charophyte and mollusc remains indicate that the sediments were formed in a wetland setting of shallow freshwater to slightly oligohaline ponds, streams and swamps. The present more northern distribution of some of the recorded taxa implies that climate conditions were probably cooler during the wetland formation. Radiocarbon age data for biogenic carbonate from two locations suggest that the wetland setting existed during the second half of Marine Isotope Stage (MIS) 3 or possibly earlier. A significantly higher water table must have existed in the basin during wetland formation; and wetter climate conditions are inferred for the catchment or at least for its highest and most humid westernmost part. Deflation and local sediment accumulation by wind and occasional sheet-wash events apparently prevailed in the region since MIS 2. Our newly presented data and inferences do not support the reconstruction of a previously reported large and relatively deep Pleistocene lake in the Al Jafr Basin. However, more extensive studies are certainly required for a detailed assessment of the Quaternary hydrological conditions in southern Jordan.

Early Pleistocene (Calabrian) Ostracoda assemblage and paleoenvironmental characteristics of the Fevzipasa Formation,Western Anatolia

The study area is located about 40km west ofAydin city in western Turkey and includesNeogene to Quaternary sediments of the Fevzipasa Formation, which unconformably overlies the Miocene rock units. The Fevzipasa Formation is composed of conglomerates, sandstones, mudstones, marls, limestones and tuff layers and is unconformably overlain by recent deposits of the Söke-Milet Basin. The lower part of the Fevzipasa Formation is represented by coarse clastics and lacustrine carbonates followed by fine to coarse-grained sandstones bearing mollusc shells. Prominent tuff layers (lower and upper tuff layers) of this dominantly sandstone succession were radiometrically dated between roughly 2 and 1Ma. Based on small mammal fauna the age of the upper part of the formation is Early to Late Pleistocene. To investigate the paleoenvironmental evolution of the succession, forty-two samples were collected along two stratigraphic sections. Ostracoda assemblages together with Chara flora, Gastropoda and Pelecypoda and fish remains were recovered from only twenty-nine samples. Ostracoda assemblages include Candona neglecta, Cyclocypris ovum, Ilyocypris gibba, I. bradyi, Heterocypris salina and Scottia cf. S. pseudobrowniana. Additionally, fish remains belonging to the Cyprinidae family (Tinca sp., Leuciscus sp. and Leuciscus etilius) and Characeae gyrogonites referable to Nitellopsis obtusa, Chara sp., C. aspera, C. globularis, C. hispida, C. vulgaris, Lychnothamnus sp. and Sphaerochara sp. occurred in the samples. The ostracod, fish, and gyrogonite records all indicate that the Fevzipasa Formation was deposited in a paleoenvironmental setting characterized by permanent and shallow water bodies. According to the identified Ostracoda assemblages and combining all available stratigraphic data, the age of middle part of the Fevzipasa Formation is suggested as Early Pleistocene (Calabrian).