Search results for "Ostracod"
showing 10 items of 58 documents
Ecologia d’ostracodes de zones humides costaneres, i aproximació a les capacitats dispersives dels microcrustacis
2016
Els aiguamolls costaners de l’est de la península Ibèrica són uns ecosistemes molt particulars que han sigut afectats de forma persistent per les activitats humanes al llarg dels segles. Les comunitats d’invertebrats aquàtics en general, i els ostracodes en particular, són alguns dels organismes que es troben en aquests ecosistemes, dels que un bon exemple a València són la Marjal dels Moros i el Racó de l’Olla. L’estudi d’aquests aiguamolls ens pot ajudar a entendre quins canvis ambientals s’han produït en els darrers anys i quins són els factors que regulen la dinàmica de les comunitats actuals. En el Racó de l’Olla i la Marjal dels Moros vam estudiar la dinàmica temporal de les comunitat…
Artificial dam lakes as suitable habitats for exotic invertebrates: Ostracoda ecology and distribution in reservoirs of the Eastern Iberian Peninsula
2014
Reservoirs are the most common deep lakes in Spain, as a consequence of water needs and dry climate. Although these aquatic systems can play an important ecological role in such an area with few large natural lakes, they can also provide new habitats for exotic species, which can colonize ecosystems that native species have not explored yet. Here we present our results for a biannual survey of the ostracod fauna from 24 reservoirs in Xuquer River basin. We check which variables affect ostracod presence, test for differences between winter and summer assemblages, and compare our data with previous available ostracod records from the same river drainage network. Our results reveal that ostrac…
Factors affecting the distribution of recent lacustrine ostracoda from the Caicedo de Yuso-Arreo Lake (Western Ebro Basin, Spain)
2005
Recent Ostracoda assemblages of the Caicedo de Yuso Lake have been described as representative of palustrine/lacustrine environments in Iberian temperate lakes. This study considers the changes in assemblages at a fixed station during two consecutive annual cycles, as well as their distribution in summer and winter profiles of the lake. Total sample-assemblages have been quantified as species diversities, measured by the Shannon-Wiener index H (S). The trends of this index are compared to physical parameters (temperature, conductivity, dissolved oxygen, CO2) of the bottom waters of this lake. The Ostracoda assemblages (8100 adults and juvenile living specimens, belonging to 20 species) are …
Depositional environment and biofacies characterisation of the Triassic (Carnian to Rhaetian) carbonate succession of Punta Bassano (Marettimo Island…
2007
AThe aims of this study are to reconstruct the geological setting of the Punta Bassano series (Marettimo Island, Egadi Archipelago, western Sicily) and its palaeogeographic evolution. The reference section for the Upper Triassic of Marettimo shows an alternation of marl and limestone beds together with brecciated levels. The limestones are both homogeneous mudstones with evaporite pseudomorphs and laminated with fenestrae. Foraminiferal, palynomorph, and ostracod associations constrain the Punta Bassano sequence to the Carnian-Rhaetian interval. The Punta Bassano succession represents a shallow inner ramp, ranging from open-marine environment with good water circulation to lagoonal and peri…
Ostracod and conodont faunal changes across the Frasnian-Famennian (Devonian) boundary at Els Castells, Spanish central Pyrenees
2008
Diverse conodont and silicified ostracod assemblages were found in the Spanish Pyrenees (Els Castells section), in the Frasnian/Famennian boundary beds (laterhenana and/orlinguiformis to latetriangularis zones), in strata below and above the well-known Kellwasser Extinction Event. Many of the ostracods studied here are conspicuous elements of the “Thuringian Mega-Assemblage”, and show maximum affinities with faunas from the southeastern Cantabrian Mountains (Spain), eastern Thuringia and the Harz (Germany). The composition of the faunas, however, is not uniform through the Els Castells section. A rather sharp break exists, roughly coinciding with the Frasnian/Famennian boundary. The break i…
Trace element variability in single ostracod valves as a proxy for hydrochemical change in Nam Co, central Tibet, during the Holocene
2014
Ostracod shells, belonging to three taxa (Leucocytherella sinensis Huang, 1982, ?Leucocythere dorsotuberosa Huang, 1982 and ?L. dorsotuberosa f. postilirata sensu Pang, 1985), were collected from two sediment cores from Lake Nam Co, on the central Tibetan Plateau. Two variants of LA–ICP–MS (laser ablation–inductively coupled plasma–mass spectrometry), spot and line-scan analyses, were used to investigate trace element concentrations (Mg, Sr, Ba, U and rare earth elements [REEs]) in single ostracod shells. The results suggest that the line-scan method can provide better precision than the spot analysis and is therefore preferred. No significant difference in trace element composition between…
On the non-malacostracan crustaceans (Crustacea: Branchiopoda, Copepoda, Ostracoda) from the inland waters of Fthiotida (Greece)
2019
In the frame of the activities of the LIFE11 NAT/GR/1014 ForOpenForests, some water bodies occurring in the "Ethnikos Drymos Oitis" (GR2440004) and "Oros Kallidromo" (GR2440006) (Sterea Ellada) were investigated with the aim of providing a first census of the composition and diversity of their crustacean fauna. Overall, the sampling of 15 water bodies (7 of them listed as "Mediterranean temporary ponds" sensu EU "Habitats Directive") led to the finding of 13 branchiopod, 11 copepod, and 7 ostracod taxa, including 4 species new for mainland Greece, i.e. the copepods Arctodiaptomus alpinus (Imhoff, 1885) and Diaptomus cf. serbicus, and the branchiopods Leptestheria dahalacensis (Rüppel, 1837)…
Rice fields as facilitators of freshwater invasions in protected wetlands: the case of Ostracoda (Crustacea) in the Albufera Natural Park (E Spain)
2014
Background: Previous studies have identified rice fields in the Mediterranean region as ‘hot spots’ for the introduction of alien freshwater organisms. Consequently, special attention should be paid when rice fields are located inside or near protected areas for the conservation of native, endangered species. To analyse the relationship between rice field environmental traits and the ecology of aquatic invaders, a study of zoobenthic communities was carried out in JulySeptember 2008 and May-August 2009 in ten rice fields located in the Albufera Natural Park (E Spain), with focus on Ostracoda. Results: A total of nine ostracod species were found including four considered exotic: Candonocypri…
The distribution of sexual reproduction of the geographic parthenogenEucypris virens(Crustacea: Ostracoda) matches environmental gradients in a tempo…
2013
Niche segregation may prevent competitive exclusion and promote local coexistence. This typically results in the occupation of different habitats. In the freshwater ostracod Eucypris virens (Jurine, 1820), the distribution of sexual and parthenogenetic populations in the temporary Lake Caracuel, central Spain, was not homogeneous. Parthenogens were found everywhere including the littoral, whereas sexuals were restricted to the centre. We investigated the hypothesis that spatial distribution responded to ecological differences. We studied the ecological significance of this segregation by linking environmental data to male presence, sexual fraction, ploidy, and genetic structure of our model…
Extreme tolerance to environmental stress of sexual and parthenogenetic resting eggs ofEucypris virens(Crustacea, Ostracoda)
2012
Summary 1. The freshwater ostracod (Ostracoda), Eucypris virens, is commonly found in European temporary pools, where its long-term persistence completely relies on the build-up of resting egg banks. Extreme tolerance of dormant eggs and seeds is widely assumed, but freshwater ostracod eggs are relatively poorly studied. The study of ostracod resting eggs is of particular relevance as it may yield the key to understanding the distribution of the sexes in many species capable of both sexual and asexual reproduction. 2. We assessed the tolerance of dried resting eggs produced by females originating from three populations with males and three all-female E. virens populations. Hatching time and…