Search results for "Patella caerulea"
showing 7 items of 7 documents
Oxygen isotopes from limpet shells: Implications for palaeothermometry and seasonal shellfish foraging studies in the Mediterranean
2017
Limpet shells are common components of many archaeological sites in the Mediterranean. To test whether δ18O values from archaeological Patella caerulea shells can serve as a reliable palaeothermometer for the Mediterranean and a reliable archive of season of collection information, we collected live P. caerulea from eight Mediterranean locations in Croatia, Israel, Libya, Malta, Tunisia, and Turkey. Shell growth patterns were studied in section, and samples for oxygen isotope analysis were milled from the shells and used to calculate sea surface temperature (SST). As with other species of limpet, SST reconstructed from P. caerulea δ18O values were lower than expected from observational reco…
Artificial environmental conditions can affect allozyme genetic structure of the marine gastropod Patella caerulea
2001
Samples of the Mediterranean limpet Patella caerulea collected from 10 sites were examined for genetic population structure. Six of the 20 identified enzymatic loci were polymorphic. The AAT* locus was polymorphic only in two samples from an artificial environment (TI2 and PE). The proportion of polymorphic loci ranged from 0.20 to 0.30, and the observed and expected mean heterozygosity varied between 0.098 and 0.076 and between 0.109 and 0.086, respectively. Mean Fis values were significantly positive in AAT*, ESTD*, PEPC-2*, and PEPD*, showing heterozygosity deficiency. In all, mean Fst value of 0.007 indicated high genetic homogeneity between the samples analyzed, whereas single-locus Fs…
Variations in physiological responses to thermal stress in congeneric limpets in the Mediterranean Sea
2014
Cardiac activity (Arrhenius breakpoint temperatures and Q10 relationships) and heat shock response (hsp70 expression) were measured in the congeneric limpets Patella rustica, P. caerulea and P. ulyssiponensis in order to test the relationship between their vertical distribution and physiological thermal tolerance. These species exhibit different vertical distributions along Mediterranean shores and despite the narrow tidal range in the Mediterranean, they experience different environmental conditions and consequently had specific thermal windows. Cardiac activity of the upper zoned P. rustica was maintained at higher temperatures than its mid- or low shore counterparts, P. caerulea and P. u…
Trace elements in shells of common gastropods in the near vicinity of a natural CO<sub>2</sub> vent: no evidence of pH-de…
2014
Abstract. There is concern that the use of natural volcanic CO2 vents as analogs for studies of the impacts of ocean acidification on marine organisms are biased due to physiochemical influences other than seawater pH alone. One issue that has been raised is whether potentially harmful trace elements in sediments that are rendered more soluble and labile in low pH environments are made more bioavailable, and sequestered in the local flora and fauna at harmful levels. In order to evaluate this hypothesis, we analyzed the concentrations of trace elements in shells (an established proxy for tissues) of four species of gastropods (two limpets, a topshell and a whelk) collected from three sites …
Morphological and molecular tools in identifying the Mediterranean limpets Patella caerulea, Patella aspera and Patella rustica
2003
Allozyme electrophoresis, a partial nucleotide sequence of a mitochondrial gene for cytochrome oxidase I (COI) and discriminant analysis of shell morphometric characters were used to study the relationships among the Sicilian marine gastropods of the Patella genus. Allozyme and mtDNA markers unequivocally distinguished the species and were very useful markers in correctly classifying the different species when morphological characters overlapped each other. Several allozyme loci and many nucleotide positions were diagnostic of species. In contrast, the discriminant analysis of simple morphometric shell characters failed to adequately discriminate the species, suggesting that environmental f…
Local consumers are the first line to control biological invasions: a case of study with the whelk Stramonita haemastoma (Gastropoda: Muricidae)
2016
The increasing spread of invasive species in the Mediterranean Sea determines several alterations in local food webs, changing the feeding habits of native organisms. The whelk Stramonita haemastoma is a widespread Mediterranean gastropod that consumes bivalves, barnacles and limpets. Previous studies showed a shift in its diet from the bivalve Mytilaster minimus to the invasive mussel Brachidontes pharaonis, presumably due to a higher energy gain. Here we tested whelks’ preference among natives and a novel prey, calculating the profitability ratio, and integrating those results with biochemical analysis on prey tissues and the routine metabolism of the whelks. Further, we used the scaled f…
Seawater carbonate chemistry and shell mineralogy, microstructure, and mechanical strength of four Mediterranean gastropod species near a CO2 seep
2017
Marine CO2 seeps allow the study of the long-term effects of elevated pCO2 (ocean acidification) on marine invertebrate biomineralization. We investigated the effects of ocean acidification on shell composition and structure in four ecologically important species of Mediterranean gastropods (two limpets, a top-shell snail, and a whelk). Individuals were sampled from three sites near a volcanic CO2 seep off Vulcano Island, Italy. The three sites represented ambient (8.15 pH), moderate (8.03 pH) and low (7.73 pH) seawater mean pH. Shell mineralogy, microstructure, and mechanical strength were examined in all four species. We found that the calcite/aragonite ratio could vary and increased sign…