Valentina Pieri

Water quality and diversity of the Recent ostracod fauna in lowland springs from Lombardy (northern Italy)

The Po river plain (northern Italy) is delimited to two mountain ridges, the Alps and the Apennines. It hosts peculiar lowland man-modified springs, locally known as “fontanili”, which originate from natural resurgences occurring along the alluvial fans of the main watercourses, namely in the transition zone from the higher to lower plain which is characterized by changes in slope profile and sediment granulometry. These habitats usually show low variation in hydrological, hydrochemical and thermal conditions throughout the year. Twenty-eight springs, located in the provinces of Lodi and Cremona (Lombardy) in the alpine sub-catchment of the Po river were sampled in summer and autumn of 2004. Twenty-three of them were typical alluvial-fan springs, while the remaining five were terrace springs. The two groups of springs showed marked differences in their hydrochemical and hydrological characteristics. Sixteen ostracod species in three families (Candonidae, Ilyocyprididae, and Cyprididae) were identified. The most frequent species were Cypria ophtalmica (19 sites), Herpetocypris reptans (16), and Prionocypris zenkeri (13). Five species were found only once: Chlamydotheca incisa, Scottia pseudobrowniana, Pseudocandona compressa and Candona neglecta. Up to 6 taxa were recorded from a single site and the average number of taxa for each site was c. 3. The associations among ostracod taxa and their occurrence in relation to environmental factors were examined. Finally, the results of this survey were compared with a similar study previously conducted in 31 alluvial fan springs of the apennine sub-catchment of the Po river.

Recent ostracods (Crustacea, Ostracoda) found in lowland springs of the provinces of Piacenza and Parma (Northern Italy)

The “fontanili” are artificial aquatic ecosystems, typical of the lowland plains of Northern Italy, exploiting natural resurgences of deep groundwater. These habitats are characterized by low variation in hydrologic, hydrochemical and thermal conditions throughout the year. Proper management is required to prevent the spring clogging by biomass accumulation. In spite of their importance as refugia for endangered species, many springs were completely abandoned in the last years and several of them will disappear. We report the results of a study carried out in 2001 on 31 springs of the provinces of Piacenza and Parma, distributed in seven areas defined on hydrological and geological considerations. Physical and chemical variables and parameters of waters were measured and ostracod samples were collected. Most of the springs showed high nitrate concentration, due to a diffuse pollution of agricultural origin. Twelve ostracod species in four families were identified. Ostracod valves were analysed by scanning electron microscopy. Cypria ophtalmica was found in all the springs; other relatively common species were Cyclocypris laevis, Notodromas persica, and Prionocypris zenkeri. The maximum number of species per site was four. Cypridopsis vidua, P. zenkeri, and N. persica showed a very localized distribution in the study area. The ostracod fauna of the “fontanili” was compared to other species assemblages found in spring habitats and to the available information on recent freshwater ostracods reported for Italy.

Using crustaceans to identify different pond types. A case study from the Alta Murgia National Park, Apulia (South-eastern Italy)

The aim of this study was to test the effectiveness of crustaceans in the identification of different pond types, including ‘Mediterranean Temporary Ponds’ (sensu ‘Habitats’ Directive) and ponds characterised by a range of hydroperiods. Thus, we performed a limnological study in the Alta Murgia National Park (central Apulia), conducting a three-year monitoring programme in 19 ponds, both temporary and permanent. Occurrence data for macrophytes and quantitative samples of crustaceans were collected contemporaneously with measures of water variables and environmental features. Based on macrophyte assessment, half of the studied waterbodies were found to include Mediterranean Temporary Pond priority habitats, and the possible relationships with the crustacean assemblages were analysed. All ponds were grouped into three different classes depending on their hydroperiod. Data analysis revealed that (i) there was a significant relationship between the distribution of crustaceans and macrophytes; (ii) crustacean richness was highest in ponds belonging to the shortest hydroperiod class considered and (iii) the different hydroperiod classes were associated with specific crustacean assemblages. This study indicates that crustaceans—in addition to macrophytes—can be used as an effective tool for the identification of different pond types.

An annotated checklist of the Recent non-marine ostracods (Ostracoda: Crustacea) from Italy

We present an updated checklist of non-marine ostracods from Italy. Data were obtained from the published literature up to April 2013 and new collections carried out in 18 out of 20 Italian regions. Altogether, 1665 ostracod samples were collected from 1241 new sites visited between 1981 and 2013. Sites were selected to encompass the most widespread types of freshwater aquatic habitats (i.e., pools, ponds, peat bogs, springs and streams, etc.). This field study led to the identification of 89 ostracod species. Five additional taxa remained at the generic level because only few (juvenile) individuals were available or the material was damaged. Of particular interest is the occurrence of four species new to Italy: Candonocypris novaezelandiae, Eucypris elongata, Ilyocypris getica and I. hartmanni. In addition, three putative new species (Pseudolimnocythere sp., Candona sp.1 and Eucypris sp.1) are left in open nomenclature. After synonymising several species and removing invalid taxa reported in the literature, the updated checklist now includes 152 species and 5 taxa identified at supraspecific level, belonging to 57 genera and 12 families (Candonidae, Cyprididae, Cytherideidae, Darwinulidae, Ilyocyprididae, Notodromadidae, Limnocytheridae, Leptocytheridae, Loxochonchidae, Hemicytheridae, Xestoleberididae and Entocytheridae). For each species, its distribution in Italy and its bibliographic records (including synonyms) for Italy are provided.

Are aquatic assemblages from small water bodies more stochastic in dryer climates? An analysis of ostracod spring metacommunities

Metacommunity ecology describes community organisation considering both environmental and spatial processes. We tested the relative importance of environmental and spatial factors on spring ostracod assemblages from four European regions characterised by different climatic conditions (e.g. aridity). Pure and shared effects of environment and space were calculated using redundancy analysis and variation partitioning. Both environmental and spatial variables significantly explain assemblage variation, although with different relevance among areas. The amount of variation explained by environmental factors decreased with increasing climate aridity. The reduced size of spring habitats makes them prone to drying events, which are more frequent in dryer climates. Frequent disturbances may lead to local extinctions followed by colonisations from nearby sites, in a source–sink dynamics. Early recolonisation leads to random assemblages and reduces the match between organisms and environmental conditions. As a consequence, a low amount of community variation can be explained by environmental variables. Conversely, the settled communities from wetter climates best fit the ecological characteristics of sites, and deterministic processes, such as species sorting, dominate the assemblages. In conclusion, in the studied regions, ostracod communities from small water bodies of dryer climates seem to be mainly driven by stochastic dynamics when compared to more continental areas.

Cryptic diversity and speciation in endemic Cytherissa (Ostracoda, Crustacea) from Lake Baikal

Lake Baikal (Siberia) is the most ancient and deepest of all ancient lakes on Earth. It holds a (mostly endemic) diversity of thousands of animal species, including a speciose radiation of ostracods of the genus Cytherissa. Applying molecular tools to this crustacean group reveals that several morphological species are actually species clusters. Based on combined 16S and 28S DNA sequence data from thirteen classic Cytherissa species and one subspecies sensu Mazepova (1990), we recognize 26 different genetic Cytherissa species, 18 with morphological variation and eight truly cryptic species. These results suggest that the actual specific diversity of Cytherissa in Lake Baikal might easily be double of what is presently known. Baikalian endemic species most likely live in the cradle in which they originated and this opens perspectives to infer modes of speciation. Our current distribution data of Cytherissa species provide first indications for both geographic (lakes basins and shores) and ecological (sediment type, water depth) separation. Our present data thus provide the first steps towards future, rigorous testing of focussed hypotheses on the causality of speciation through either allopatric isolation or parapatric ecological clines.

(Eco)toxicological maps: A new risk assessment method integrating traditional and in silico tools and its application in the Ledra River (Italy)

Contaminants giving rise to emerging concern like pharmaceuticals, personal care products, pesticides and Endocrine Disrupting Chemicals (EDCs) have been detected in wastewaters, as reported in the literature, but little is known about their (eco)toxicological effects and consequent human health impact. The present study aimed at overcoming this lack of information through the use of in silico methods integrated with traditional toxicological risk analysis. This is part of a pilot project involving the management of wastewater treatment plants in the Ledra River basin (Italy). We obtained data to work up a global risk assessment method combining the evaluations of health risks to humans and ecological receptors from chemical contaminants found in this specific area. The (eco)toxicological risk is expressed by a single numerical value, permitting the comparison of different sampling sites and the evaluation of future environmental and technical interventions.