The

No abstract

Four perennial rheocrene springs located between 919 and 1252 m a.s.l. on substrata characterized by different lithologies were studied. Water samples and invertebrates were collected seasonally for one year. The crenic fauna was collected using three sampling techniques: moss washing, drift tubes and benthic traps. Each sampling technique was particularly efficient for collecting specific taxa typical of the different habitats (crenophilous crustaceans and crenoxenic benthic insects were dominant in benthic traps and moss; crenophilic, stygophilic and stygobiotic crustaceans in drift tubes). A total of 3,284 invertebrates belonging to 54 taxa were collected. Ostracoda, Harpacticoida, and Diptera were the most abundant taxa. Species assemblages collected at each spring, in each season, in traps and mosses, differed among springs, and, based on invertebrate assemblages, the ordination of the investigated springs did not correspond to that based on environmental parameters. Of the environmental variables only pH and temperature explained the diversity pattern. Assemblages collected from different habitats also differed: benthic traps collected mainly Chironomidae, Ostracoda, other Diptera, crenophilous Harpacticoida, and Gastropoda; in moss assemblages, the fauna was mostly represented by crenophilic Harpacticoida, Ostracoda, Plecoptera, Chironomidae. Finally, the groundwater assemblages, collected with drift tubes, were dominated by crenophilous Harpacticoida, Chironomidae and Plecoptera. Variation in number of taxa over time was observed in traps and moss samples, whereas drift tubes showed no seasonality. Meiofauna (i.e., permanent meiofauna, represented by Nematoda, Copepoda, Ostracoda, and Hydrachnidia, and temporary meiofauna, represented by early instars of insect larvae) dominated all habitats, probably because of constant flow and favourable habitats such as moss. The presence of mosses was a factor that increased the species diversity of the investigated springs; drift tubes allowed most of the stygobiotic taxa to be collected, although this technique did not necessarily increase the total number of taxa collected. In addition to the array of habitats, other factors, such as geology, might influence the structure of invertebrate communities. The diversity of the investigated springs was strictly dependent on the presence of different microhabitats and local environmental conditions

Ilyocypris Brady and Norman () is a widespread freshwater ostracod genus including about 30 living and 190 fossil species. The specific identification of the living Ilyocypris relies mainly on the appendages. An identification exclusively based on valves is rather complicated because of a high intraspecific variability of their characters in several species. This study aims to test the taxonomic significance of the valves characters through the examination of specimens unambiguously identified on the basis of their soft part morphology, in order to provide useful taxonomic criteria for the identification of Ilyocypris shells in fossil assemblages. Sixty‐five ilyocypridid specimens collected in mainland Italy and surrounding islands were analyzed. The patterns of valve surface ornamentation and of marginal ripplets were examined by electron microscopy. Moreover, the geometric morphometric analysis of the valve outlines was performed. Sixty‐two specimens could be easily accommodated in eight Ilyocypris species (I. bradyi, I. decipiens, I. getica, I. gibba, I. hartmanni, I. inermis, I. monstrifica, and I. salebrosa) according to the morphology of their appendages. Three additional specimens, with soft parts typical of Ilyocypris but clearly distinct valve morphology, were left in open nomenclature. Our results show that the outline analysis is often a valid tool to discriminate between different species. Conversely, valve ornamentation displays different degrees of intraspecific variability in some Ilyocypris species. The marginal ripplets are constant within each species population, but they do not always mirror the patterns reported by other authors; therefore, we do not consider them as reliable diagnostic character for specific determination. This study confirms that the identification of Ilyocypris species requires accurate description of appendages as well as external and internal carapace characteristics, and stresses the advantage of a combined neontological and paleontological investigation in solving taxonomic problems related to non‐marine ostracods.

From August 1981 to July 2007, 200 inland water bodies were sampled to gather information on the Recent ostracod fauna of Friuli Venezia Giulia (NE Italy). A total of 320 samples were collected from surface, interstitial and ground waters. Whenever possible, ostracod identification was performed at species level based on the morphology of both valves and limbs. Seventy-four taxa in 30 genera belonging to 9 different families (Darwinulidae, Candonidae, Ilyocyprididae, Notodromadidae, Cyprididae, Limnocytheridae, Cytheridae, Leptocytheridae and Xestoleberididae) were identified. The maximum number of taxa per site was seven. The most common species was Cypria ophthalmica (133 records), followed by Cyclocypris ovum (86 records), C. laevis (49 records), Cypridopsis vidua (40 records) and Notodromas persica (28 records). Of particular relevance is the occurrence of six species new to Italy: Microdarwinula zimmeri, Penthesilenula brasiliensis, Fabaeformiscandona wegelini, Pseudocandona semicognita, Candonopsis scourfieldi, and C. mediosetosa. Scanning electron microscopy images of valves are provided for most of the described taxa. Geographical distribution of ostracods and their occurrence in relation to environmental variables were examined. The results of this study indicate that Friuli Venezia Giulia hosts a very diverse ostracod fauna, representing a significant proportion of all ostracod taxa known thus far from Italy