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We present a genome assembly from an individual Patella vulgata (the common limpet; Mollusca; Gastropoda; Patellogastropoda; Patellidae). The genome sequence is 695.4 megabases in span. Most of the assembly is scaffolded into 9 chromosomal pseudomolecules. The mitochondrial genome has also been assembled and is 14.93 kilobases in length. Gene annotation of this assembly on Ensembl identified 19,378 protein coding genes.

Limpets (Patella spp.) are marine gastropods that inhabit rocky shores along the coasts of Europe, the Mediterranean, Macaronesia and the north-west coast of Africa. Being considered key species, limpets have an important role regulating algal assemblages in coastal communities. The goal of this work was to evaluate the influence of sea temperature on the respiration rate of four limpet species occurring in mainland Portugal, in line with predictions from the metabolic theory of ecology. The individuals were collected from rocky shores in Portugal and exposed to sea temperatures ranging from 6–28°C for respiration rate assessments. Following the estimation of the relationship between oxygen consumption and temperature the activation energy was calculated. In parallel, low and high thermal thresholds were determined for three of the species. The results indicated that P. ulyssiponensis oxygen consumption increased linearly with sea temperature and the remaining species presented the same tendency. The values of activation energy ranged between 0.33–0.76 eV. For P. ulyssiponensis , the highest activation energy indicated that this species is more sensitive to temperature variations while for the tested temperatures it presented a higher thermal tolerance limit than the other species. Such findings indicate that P. ulyssiponensis is the most susceptible of these species to climate change, in line with the tolerance–plasticity trade-off hypothesis. This work provides a good starting point for understanding the effect of sea temperature on oxygen consumption in Patella spp. and for comprehending sensitivity of limpets to temperature increases under future climate change scenarios. [ABSTRACT FROM AUTHOR]

Sclerochronological data from archaeological shell middens provides crucial information about past environments and subsistence practices of coastal human populations. These studies rely on a strong knowledge of species-specific growth patterns, as it is the main driver of the quantity and quality of information recorded in biogenic carbonates. The limpet Patella vulgata is highly represented in eastern Atlantic shell middens. In this study, the micro-increment formation of its shell was investigated through in situ marking experiments, using calcein fluorochrome (150 mg.L−1) coupled with cohort study and local SST recording. Calcein-stained growth structures confirmed the efficacy of the fluorochrome, and our results shows a disturbed tidal increment formation, with on average more than one increment per day, but less than one increment per tide. Growth is not mainly influenced by environmental factors, but could be forced by competition among limpets and endogenous factor (age and sex), resulting in a highly heterogenous population in terms of growth rates. Growth interruption could not be detected solely by micro-increment observation, causing a major issue for cross-calibration with recorded temperatures, sclerochronological estimation of growth and isotopic profiles. For palaeo-environmental application, we recommend to consider that there is no general population pattern, even at a micro-habitat scale. [ABSTRACT FROM AUTHOR]

Positive species interactions such as facilitation are important for enabling species to persist, especially in stressful conditions, and the nature and strength of facilitation varies along physical and biological gradients. Expansion of coastal infrastructure is creating hotspots of invasive species which can spillover into natural habitats, but the role of positive species interactions associated with biological invasions remains understudied. Theory suggests that stronger biotic pressure in natural habitats inhibits invasion success. In space‐limited marine systems, sessile organisms can overcome this limiting resource by settling as an epibiont on a substrate organism – basibiont. Using a series of spatially extensive surveys, we explored the role of invasive and native basibionts in providing habitat for other invasive and native epibionts, and tested whether environmental context (i.e. if the receiving habitat was natural or artificial), altered ecological outcomes. Overall, provision of space by basibionts was more important for invasive epibionts than for native epibionts but was dependent on the environmental context. Invasive basibionts facilitated invasive epibionts in natural habitats, and appeared to be more important for native epibionts in artificial habitats respectively. Native basibionts facilitated invasive, but not native epibionts in both natural and artificial habitats. These results advance our understanding of facilitation and highlight the idiosyncratic nature of biofouling and epibiosis, and the potentially important influence of environmental context. The degree to which native habitat‐forming species versus invasive habitat‐forming species either do or do not facilitate other native or non‐native species is a rich area for investigation. Experimental work is required to disentangle the processes underpinning these patterns. [ABSTRACT FROM AUTHOR]

In Agadir Bay, a study evaluated pollution biomarkers in the mollusk species Patella vulgata. Samples were collected seasonally from September 2021 to September 2022 at two distinct coastal sites within Agadir Bay: Cap Ghir and Anza Beach. Notable variations were observed in biomarkers like malondialdehyde, with a peak at 10.62 nmol/mg P in spring 2022 at Anza Beach. Catalase activity spiked in spring at 69.56 µmol/min/mg P for Cap Ghir and 72.73 µmol/min/mg P for Anza Beach. Acetylcholinesterase showed a decrease at 9.84 nmol/min/mg P in autumn at Anza Beach. Meanwhile, glutathione-S-transferase recorded an increase to 317.96 nmol/min/mg P at Cap Ghir in spring 2022. Using the Integrated Biomarker Response (IBR), these results were visualized, highlighting more stress in mollusks from Anza Beach compared to Cap Ghir. This research provides critical insights into the environmental effects on P. vulgata and potential conservation strategies. [Display omitted] • Patella vulgata is used to monitor pollution levels by researchers. • The IBR index confirms that Anza beach is more exposed to chemical stress than Cap Ghir. • Biomarker analysis shows heightened pollution stress in Anza beach. [ABSTRACT FROM AUTHOR]

Highlights • The embryo-larval bioassay with Patella spp. showed sensitivity to Cu, Zn, Cd and Pb, comparable to other marine bioassays. • Patella spp. accumulates higher concentrations of Cd, As and Cu than Mytilus sp. • Mytilus sp. accumulates higher concentrations of Hg, Zn, Cr and organic contaminants than Patella spp. • Accumulation in limpets showed a spatial pattern of contamination similar to that shown by mussels and sediments. • Patella spp. comes out as good substitute/complement to mussels for biomonitoring of marine pollution. Abstract The use of limpets of the genus Patella as indicators of environmental quality is a priori promising, but few data are available in relation to their sensitivity to toxicants or their ability to accumulate pollutants. The aim of this work was to evaluate the use of Patella spp. as model organisms by (1) assessing the sensitivity of limpet embryos to some common pollutants, (2) validating the use of the limpet embryo-larval bioassay using natural sediment samples, and (3) analyzing the presence of pollutants by using Patella spp. as sentinel species. The obtained EC 50 values ranged between 33 and 84 µg/L for Cu, 749–1163 for Cd, 317–1103 for Zn and 813–3411 µg/L for Pb; these sensitivity ranges were similar to those of other marine invertebrates used in ecotoxicology. It was not possible to validate the bioassay with natural samples, since the sampled sites did not cause significant toxicity. Patella spp. accumulated metals and organic pollutants in their soft tissues, showing higher concentrations than mussels for some metals (Cd, As and Cu) and lower concentrations for others (Hg, Zn, Cr), as well as for organic pollutants. Furthermore, bioaccumulation in limpets showed a spatial pattern of contamination similar to that shown by mussels and sediments, revealing limpets as a very good substitute/complement to mussels for biomonitoring marine pollution, especially in sites where mussel populations are absent or present at low numbers. [ABSTRACT FROM AUTHOR]

We present a genome assembly from an individual Patella vulgata (the common limpet; Mollusca; Gastropoda; Patellogastropoda; Patellidae). The genome sequence is 695.4 megabases in span. Most of the assembly is scaffolded into 9 chromosomal pseudomolecules. The mitochondrial genome has also been assembled and is 14.93 kilobases in length. Gene annotation of this assembly on Ensembl identified 19,378 protein coding genes., Competing Interests: No competing interests were disclosed., (Copyright: © 2023 Hawkins SJ et al.)

Zooarchaeological faunal remains are commonly examined to investigate harvesting behavior. We determined limpet (Patella vulgata) shell size and shape, and estimated shell age from several middens at the Late Norse Sandwick South Site, Unst, Shetland, UK, whose strata represent distinct occupational phases (Phase 1: AD 1100-1200, Phase 2: AD 1200-1250, Phase 3: AD 1250-1350). Our goal was to determine if the many limpets found there could provide insight into Norse harvesting behavior. Shell length, conicity, and modeled age all declined between Phases 1 and 2, suggesting intensive, size-selective harvesting of limpets and a shift to harvesting lower in the intertidal zone between phases. Length and conicity varied in Phases 2 and 3 and no major changes seem to have occurred over these periods, indicating that harvesting maintained the limpet population at an impacted level throughout the later phases. The conicity decline between Phases 1 and 2 may also have been caused by increased storminess that accompanied the onset of the Little Ice Age. The mean length of modern limpet populations near the Norse site did not differ from the archaeological phases, but did vary among collection years. Limpets were 26% larger in 2015 than in 2012 and 2013, indicating that large interannual variations in population structure can occur over short time periods. Potentially the result of extreme storms removing small limpets, this result raises the possibility that size and conicity changes during the Sandwick South Site occupation, as well as in other early populations, could also be the result of environmental factors rather than human harvesting alone. We feel, however, that the most parsimonious explanation for the patterns we document is human harvesting. [ABSTRACT FROM AUTHOR]

Mapping species' geographical distribution is fundamental for understanding current patterns and forecasting future changes. Living on rocky shores along the intertidal zone, limpets are vulnerable to climate change, as their range limits are controlled by seawater temperature. Many works have been studying limpets' potential responses to climate change at local and regional scales. Focusing on four Patella species living on the rocky shores of the Portuguese continental coast, this study aims to predict climate change impacts on their global distribution, while exploring the role of the Portuguese intertidal as potential climate refugia. Ecological niche models combine occurrences and environmental data to identify the drivers of these species' distributions, define their current range, and project to future climate scenarios. The distribution of these limpets was mostly defined by low bathymetry (intertidal) and the seawater temperature. Independent of the climate scenario, all species will gain suitable conditions at the northern distribution edge while losing in the south, yet only the extent of occurrence of P. rustica is expected to contract. Apart from the southern coast, maintenance of suitable conditions for these limpets' occurrence was predicted for the western coast of Portugal. The predicted northward range shift follows the observed pattern observed for many intertidal species. Given the ecosystem role of this species, attention should be given to their southern range limits. Under the current upwelling effect, the Portuguese western coast might constitute thermal refugia for limpets in the future. • Ecological niche models were used to predict limpets' distributions while projecting to future climate scenarios. • Seawater temperature is the major driver of limpets' global distribution. • Poleward shifts with possible northward expansion were predicted for the future. • The Portuguese western coast is probably a thermal refugium for limpets in the future. [ABSTRACT FROM AUTHOR]

Experiments and observations were carried out to investigate the response of the Patella vulgata limpet shell to impact. Dropped-weight impact tests created damage that usually took the form of a hole in the shell's apex. Similar damage was found to occur naturally, presumably as a result of stones propelled by the sea during storms. Apex holes were usually fatal, but small holes were sometimes repaired, and the repaired shell was as strong as the original, undamaged shell. The impact strength (energy to failure) of shells tested in situ was found to be 3.4-times higher than that of empty shells found on the beach. Surprisingly, strength was not affected by removing the shell from its home location, or by removing the limpet from the shell and allowing the shell to dry out. Sand abrasion, which removes material from the apex, was found to have a strong effect. Shells were also subjected to repeated impacts, which caused failure after 2-120 repetitions. In situ shells performed poorly in this test. It is proposed that the apex acts as a kind of sacrificial feature, which confers increased resistance but only for a small number of impacts. Microscopy showed that damage initiates internally as delamination cracks on low-energy interfaces, leading to loss of material by spalling. This mode of failure is a consequence of the layered structure of the shell, which makes it vulnerable to the tensile and shear stresses in the impact shock wave. [ABSTRACT FROM AUTHOR]

As climate change is expected to impose increasing thermal stress on intertidal organisms, understanding the mechanisms by which body temperatures translate into major biogeographic patterns is of paramount importance. We exposed individuals of the limpet Patella vulgata Linnaeus, 1758, to realistic experimental treatments aimed at disentangling the contribution of water and air temperature for the buildup of thermal stress. Treatments were designed based on temperature data collected at the microhabitat level, from 15 shores along the Atlantic European coast spanning nearly 20° of latitude. Cardiac activity data indicated that thermal stress levels in P. vulgata are directly linked to elevated water temperature, while high air temperature is only stressful if water temperature is also high. In addition, the analysis of the link between population densities and thermal regimes at the studied locations suggests that the occurrence of elevated water temperature may represent a threshold P. vulgata is unable to tolerate. By combining projected temperatures with the temperature threshold identified, we show that climate change will likely result in the westward expansion of the historical distribution gap in the Bay of Biscay (southwest France), and northward contraction of the southern range limit in south Portugal. These findings suggest that even a minor relaxing of the upwelling off northwest Iberia could lead to a dramatic increase in thermal stress, with major consequences for the structure and functioning of the intertidal communities along Iberian rocky shores. [ABSTRACT FROM AUTHOR]

The use of three limpet species, Patella vulgata Linnaeus, 1758, Patella depressa Pennant, 1777 and Patella ulyssiponensis Gmelin, 1791 as model organisms in marine ecotoxicology has been evaluated. Initial laboratory experiments were aimed to standardize a biological test with embryos and larvae of Patella spp , establishing the percentage of normal trochophore larvae as endpoint. Before conducting in vitro fertilization, oocytes must be maturated artificially by incubation in an alkaline solution; therefore, alkalinizing agent, pH and time of eggs alkalinization were evaluated. Moreover, time of sperm activation, optimum sperm and oocytes concentration during fertilization, gamete contact time, use of stirring during the fertilization, egg concentration and incubation temperature were examined. Minimum sample size per treatment was also estimated. Exposure of oocytes for 10 min to FSW alkalinized with NH 4 OH at pH 9.0, the use of undiluted sperm pre-activated during 45 min and a concentration of 200 oocytes mL −1 , a gamete-contact time of 180 min and egg incubation at 18 °C during 24 h at a concentration of 80 eggs mL −1 were the conditions allowing maximal embryo-larval development success. With an error of 0.05, a sampling size ≥320 allows a 95% confidence in the estimate. This Patella spp . acute bioassay fulfills a number of important a priori requirements to be used in ecotoxicological studies. Nevertheless, in vitro fertilization requires considerable handling, which may lead to failure in fecundation. Such difficulties are also addressed, in order to facilitate the routine use of this protocol by other laboratories. [ABSTRACT FROM AUTHOR]

Understanding the physiological abilities of organisms to cope with heat stress is critical for predictions of species’ distributions in response to climate change. We investigated physiological responses (respiration and heart beat rate) of the ectotherm limpet Patella vulgata to heat stress events during emersion and the role of seasonal and microclimatic acclimatization for individual thermal tolerance limits. Individuals were collected from 5 microhabitats characterized by different exposure to solar radiation in the high intertidal zone of a semi-exposed rocky shore in winter and summer of 2014. Upper thermal tolerance limits (heat coma temperatures – HCT s, and heart rate Arrhenius break temperatures - ABT s) were determined for individuals from each microhabitat in both seasons under laboratory conditions. While we found a clear seasonal acclimatization, i.e., higher HCT s and ABT s in summer than in winter, we did not find evidence for microhabitat-specific responses that would suggest microclimatic acclimatization. However, operative limpet temperatures derived from in-situ temperature measurements suggest that individuals from sun exposed microhabitats have a much narrower thermal safety margins than those from less exposed surfaces or within crevices. Microhabitat specific thermal safety margins caused by high thermal heterogeneity at small spatial scales and the lack of short term acclimatization will likely shape small scale distribution patterns of intertidal species in response to the predicted increase in the frequency and intensity of heat waves. [ABSTRACT FROM AUTHOR]

The abundance, accessibility and value of limpets as a source of food and bait for coastal peoples have resulted in their high frequency in shell middens worldwide. The limpet Patella vulgata is found in middens from the Mediterranean to Norway, and morphometric and sclerochronological analyses of its shell can provide insight into harvesting patterns and paleoenvironmental variables valuable in reconstructing climate. Previous work with P. vulgata has relied on lines on the exterior of the shell, or on lines exiting on the shell surface in shell cross-section, as annual or sub-annual markers. Shell damage may compromise these lines and limit the use of some shells, but growth lines are also found in the better-preserved shell apex. We investigated whether the growth lines in the apex of P. vulgata from two locations in Northern Europe are annual using calcein-marking and recapture. Investigations were performed at one site in the Shetland Islands (UK) and at one site at the northern limit of P. vulgata's range in Northern Norway. We also used laser ablation to measure the concentration of minerals in the shells of two individuals from Shetland to determine if patterns of minerals suggested as bioproxies for temperature and productivity varied annually. All individuals deposited one growth line in the apex during their year in the field, and the lowest ratios of Sr/Ca and Ba/Ca and to a lesser extent Mg/Ca were coincident with annual lines on the shells from Shetland. Growth at both sites was modelled using the von Bertalanffy growth function, and apex growth was nearly five times faster in Shetland than in Norway, probably a result of differences in temperature between the two locations. [ABSTRACT FROM AUTHOR]

The limpet Patella vulgata is a key species of northern Atlantic rocky shore-associated communities, and is commonly considered to be important in regulating populations of canopy-forming Ascophyllum nodosum, through consumption of propagules and young recruits. Although P. vulgata is usually regarded as a non-selective epilithic biofilm grazer, a role in the collapse of established A. nodosum through grazing of adult plants has been repeatedly suggested. Factors controlling the preference of P. vulgata for epilithic biofilm or adult algae are still not clearly established. Here, we test the hypothesis that the diet of P. vulgata is mainly driven by the local availability of food sources. Limpets were sampled along the first 6 metres of an A. nodosum bed–bare rock gradient. Stable isotope ratios of their muscle tissue and digestive glands were measured. The contribution of A. nodosum to the diet of limpets was the highest in the immediate vicinity of macroalgae beds, which confirmed our initial hypothesis. However, the contribution of epilithic biofilm did not match our hypothesis, being the lowest for limpets colonizing bare rock. Instead, these limpets relied on a wide array of sources, including ephemeral green algae, biofilm and drifting A. nodosum fragments. Overall, our results indicate that A. nodosum can be readily grazed by limpets, which challenges the hypothesis that these macroalgae dominate rocky shores due to the absence of strong top-down control exerted by herbivores. Our results also highlight the need to consider the small spatial scale to understand the dynamic of herbivore–algae interactions in natural environments. [ABSTRACT FROM PUBLISHER]

The reproductive cycle and physiological status of five populations of Patella vulgata have been studied along the Galician coast from July 2010 to June 2011. The use of generalized linear model has allowed to obtain parameters such as Day 50 and Day 95 , which helped compare reproductive cycles among populations and allowed to determine the significance of the effect of size and degree of exposure on the start and duration of the cycle. On the other hand, a standardized condition index has been established, which enables the comparison of samples collected in different sites or seasons and composed by individuals of different size. Moreover, the use of a generalized nonlinear least squares model has allowed assessing the temporal variability of the physiological status of the populations and the effect of size and degree of exposure on its different components. This has contributed some useful information for planning a sustainable exploitation of this resource: sheltered areas turned out to be more productive, in terms of biomass. The reproductive cycle starts earlier and its duration is longer in sheltered areas. In addition, organisms showed minimum condition indexes during spawning periods, which makes these periods less suitable for the exploitation, both from a biological and from a commercial point of view. Larger organisms showed longer spawning periods. This highlights the importance of taking size composition into account, seeking to maintain a size structure which enables a reproductive period which is long enough to ensure future recruitment success. [ABSTRACT FROM AUTHOR]

The inter- and intra-crystalline fractions of Patella vulgata limpets recovered from archaeological sites in Northern Spain (covering Neolithic, Mesolithic, Magdalenian, Solutrean, and Aurignacian periods) were examined for amino acid composition and racemisation over time. The calcitic apex and rim areas of the shells were found to probably be composed of similar proteins, as the D/L values and amino acids were comparable and varied in the same way with increasing age; however, the mineral structures present in these areas differed. The aragonitic intermediate part of the shell showed a distinctly different amino acid composition and mineral structure. The main protein leaching from the inter-crystalline fraction occurred within the first 6000 yr after the death of the organism. In contrast, the intra-crystalline fraction — comprised of a different protein composition than the inter-crystalline fraction — appeared to behave as a closed system for at least 34 ka, as reflected by the lack of a significant decrease in the amino acid content; however, changes in the amino acid percentages occurred during this period. The concentration of aspartic acid remained almost constant with age both in inter- and intra-crystalline proteins, and its contribution to the total amino acid content increased with age at the expense of other amino acids such as glutamic acid, serine, glycine and alanine. Temperature is thought to play a key role in the amino acid racemisation of P. vulgata and could explain why in the localities belonging to the Gravettian and Solutrean period, which formed during relatively cold conditions, D/L values were similar to those detected in shells from sites formed during the Magdalenian. [ABSTRACT FROM AUTHOR]

This study investigated the characterization of proteins from the Irish limpet ( Patella vulgata ) and assessed the in vitro biological activities of hydrolysates obtained following gastrointestinal digestion (INFOGEST) of a limpet protein concentrate (LPC). The physicochemical properties and the digestibility of the LPC were investigated, along with the angiotensin-converting enzyme (ACE) inhibition and antioxidant activities of the LPC-digested samples. All the digested samples examined outperformed the LPC in terms of activity. Peptides were identified using LC-MS/MS after digestion. A total of 38 and 19 peptides were identified in LPC-G and LPC-GI, respectively, using a database search and a de novo approach. Most of the identified peptides had hydrophobic amino acids, which may contribute to their antioxidant and ACE inhibitory activities. The findings of this study showed that LPC has high nutritional quality with good digestibility and could serve as a potential source of antioxidative and ACE inhibitory peptides following gastrointestinal digestion.

Abstract: Artificial diagenesis of the intra-crystalline proteins isolated from Patella vulgata was induced by isothermal heating at 140 °C, 110 °C and 80 °C. Protein breakdown was quantified for multiple amino acids, measuring the extent of peptide bond hydrolysis, amino acid racemisation and decomposition. The patterns of diagenesis are complex; therefore the kinetic parameters of the main reactions were estimated by two different methods: 1) a well-established approach based on fitting mathematical expressions to the experimental data, e.g. first-order rate equations for hydrolysis and power-transformed first-order rate equations for racemisation; and 2) an alternative model-free approach, which was developed by estimating a “scaling” factor for the independent variable (time) which produces the best alignment of the experimental data. This method allows the calculation of the relative reaction rates for the different temperatures of isothermal heating. High-temperature data were compared with the extent of degradation detected in sub-fossil Patella specimens of known age, and we evaluated the ability of kinetic experiments to mimic diagenesis at burial temperature. The results highlighted a difference between patterns of degradation at low and high temperature and therefore we recommend caution for the extrapolation of protein breakdown rates to low burial temperatures for geochronological purposes when relying solely on kinetic data. [Copyright &y& Elsevier]

Abstract: This study successfully isolates a fraction of intra-crystalline proteins from shells of the marine gastropod Patella vulgata and assesses the suitability of these proteins for IcPD (Intra-crystalline Protein Diagenesis) geochronology. We discuss the mineralogical composition of this gastropod, investigated for the first time by X-ray diffraction mapping, and use the results to inform our sampling strategy. The potential of the calcitic rim and of a bulk sample (containing both apex and rim) of the shell to act as stable repositories for the intra-crystalline proteins during diagenesis is examined. The composition and the diagenetic behaviour of the intra-crystalline proteins isolated from different locations within the shell are compared, highlighting the necessity of targeting consistent sampling positions. We induced artificial diagenesis of both intra-crystalline and whole-shell proteins by conducting high-temperature experiments in hydrous environment; this allowed us to quantify the loss of amino acids by leaching and therefore evaluate the open- or closed-system behaviour of the different fractions of proteins. The results obtained provide further confirmation that patterns of diagenesis vary according to the protein sequence, structure, and location within or outside the intra-crystalline fraction. As Patella is frequently found in the fossil record, both in archaeological and geological contexts, the application of IcPD geochronology to this biomineral opens up the possibility to obtain reliable age information from a range of sites in different areas of the world. [Copyright &y& Elsevier]

Intertidal molluscs are known to possess specific respiratory organs that permit aerial breathing during emersion. Patella vulgata is a widely distributed intertidal species found from low-water spring tide to high-water neap tidal level. In order to determine metabolic adaptations to habitat, carbon fluxes associated with respiration and calcification of P. vulgata living at high-shore, middle-shore and low-shore levels were compared. Seasonal aerial respiration was measured using an infrared gas analyser; seasonal underwater respiration and calcification were calculated from dissolved inorganic carbon and total alkalinity. P. vulgata showed net CaCO deposition at all seasons, although the high-shore level limpet annual calcification rate was relatively low due to longer air exposure. Both aerial and underwater respiration rates were highly correlated with seasonal temperature variations and followed the vertical shore gradient, with stronger fluxes for low-shore tidal level limpets and lower fluxes for high-shore level limpets that must limit energy expenditure. P. vulgata appears to be well adapted to aerial exposure, with average hourly respiration fluxes stronger in air than in water. This study demonstrates that P. vulgata calcification and respiration are reduced in upper shore levels and are important factors determining the upper distribution limit of the species. [ABSTRACT FROM AUTHOR]

Abstract: Seasonal sea-surface temperature (SST) variability during the Medieval Climate Anomaly (MCA), which corresponds to the height of Viking exploration (800–1200AD), was estimated using oxygen isotope ratios (δ18O) obtained from high-resolution samples micromilled from archaeological shells of the European limpet, Patella vulgata. Our findings illustrate the advantage of targeting SST archives from fast-growing, short-lived molluscs that capture summer and winter seasons simultaneously. Shells from the 10th to 12th centuries (early MCA) were collected from well-stratified horizons, which accumulated in Viking shell and fish middens at Quoygrew on Westray in the archipelago of Orkney, Scotland. Their ages were constrained based on artifacts and radiocarbon dating of bone, charred cereal grain, and the shells used in this study. We used measured δ18OWATER values taken from nearby Rack Wick Bay (average 0.31±0.17‰ VSMOW, n=11) to estimate SST from δ18OSHELL values. The standard deviation of δ18OWATER values resulted in an error in SST estimates of ±0.7°C. The coldest winter months recorded in the shells averaged 6.0±0.6°C and the warmest summer months averaged 14.1±0.7°C. Winter and summer SST during the late 20th century (1961–1990) was 7.77±0.40°C and 12.42±0.41°C, respectively. Thus, during the 10th to 12th centuries winters were colder and summers were warmer by ~2°C and seasonality was higher relative to the late 20th century. Without the benefit of seasonal resolution, SST averaged from shell time series would be weighted toward the fast-growing summer season, resulting in the conclusion that the early MCA was warmer than the late 20th century by ~1°C. This conclusion is broadly true for the summer season, but not true for the winter season. Higher seasonality and cooler winters during early medieval times may result from a weakened North Atlantic Oscillation index. [Copyright &y& Elsevier]

Abstract: Seasonal sea-surface temperature variability for the Neoglacial (3300–2500BP) and Roman Warm Period (RWP; 2500–1600BP), which correspond to the Bronze and Iron Ages, respectively, was estimated using oxygen isotope ratios obtained from high-resolution samples micromilled from radiocarbon-dated, archaeological limpet (Patella vulgata) shells. The coldest winter months recorded in Neoglacial shells averaged 6.6±0.3°C, and the warmest summer months averaged 14.7±0.4°C. One Neoglacial shell captured a year without a summer, which may have resulted from a dust veil from a volcanic eruption in the Katla volcanic system in Iceland. RWP shells record average winter and summer monthly temperatures of 6.3±0.1°C and 13.3±0.3°C, respectively. These results capture a cooling transition from the Neoglacial to RWP, which is further supported by earlier studies of pine history in Scotland, pollen type analyses in northeast Scotland, and European glacial events. The cooling transition observed at the boundary between the Neoglacial and RWP in our study also agrees with the abrupt climate deterioration at 2800–2700BP (also referred to as the Subboreal/Subatlantic transition) and therefore may have been driven by decreased solar radiation and weakened North Atlantic Oscillation conditions. [Copyright &y& Elsevier]

Abstract: The concentrations of 24 parental and methylated polycyclic aromatic hydrocarbon (PAH) levels in common limpet (Patella vulgata) were measured in 15 coastal localities of the southern Bay of Biscay and 2 sites per locality for 2 years (spring and autumn of 2004 and 2005, respectively). Although the average concentrations shown a wide variability among the sites and the season, several sites showed a remarkable high concentration (PAHtot>900ngg−1 d.w.) or medium (300–800ngg−1 d.w) levels, but in most of the cases the initial high concentrations decreased sharply from one campaign to the following. Moreover, based on ratios of individual isomers concentration, petrogenic and pyrolitic sources were distinguished suggesting more than one source. Finally, based on the results of this work and comparing with previously reported data, it can concluded that limpets can be used as sentinel organisms in coastal environmental monitoring, even when oil spills are involved. [Copyright &y& Elsevier]

Abstract: Concentration of 99Tc has been measured in fucoids and molluscs, sampled in a sheltered intertidal at the southwest coast of Norway from February to November 2006. The concentrations of 99Tc in molluscs differed significantly between species. The filtering bivalve Mytilus edulis had the lowest concentrations with averages of 2.3–5.9Bqkg−1 d.w., while the herbivorous gastropods Littorina littorina, Littorina obtusata and Patella vulgata had higher concentrations. P. vulgata and L. obtusata had the highest concentrations, 40–47 and 26–30Bqkg−1 d.w., respectively. L. obtusata has a specialized habit of living, and prefers to feed on fucoids. P. vulgata can graze extensively on the fucoid Ascophyllum nodosum when available. Fucoids are known to have very high uptake of 99Tc, and this was also found in the present study. The high 99Tc-concentrations of L. obtusata and P. vulgata are most likely due to their habit of feeding on fucoids. [Copyright &y& Elsevier]

Intertidal gastropods and bivalves are important hosts for a wide range of metazoan parasites, which may exert a variety of negative effects on their hosts with consequences for mollusc population dynamics and community structure. Although vital for our understanding of the relative importance of parasites in intertidal ecosystems, quantitative information on macroparasite communities in molluscs is still largely missing. We examined the macroparasite community in Littorina littorea, Nucella lapillus, Patella vulgata and Mytilus edulis/galloprovincialis from rocky shore habitats on the south coast of Ireland. In total, twelve macroparasite taxa belonging to four major parasite groups were found in 3900 examined host individuals from sixteen intertidal localities. Digenean trematodes were the dominant parasite group, occurring in all of the investigated mollusc species and at all sampling sites. The macroparasite community in gastropods was largely similar to the species composition reported from other European shore localities, possibly due to a wide distribution of bird final hosts. In contrast, the parasite community composition observed in mussels showed obvious differences when compared to data on macroparasites in mussels from soft sediment habitats, which is probably related to differences in the species composition of gastropods acting as first intermediate hosts on rocky shores. Comparatively low infection rates in molluscs on the south coast of Ireland indicate differences in the abundance of bird final hosts as well as less suitable conditions for parasite transmission. Thus, effects of parasitism on the molluscan hosts can be assumed to be rather low, which is favourable from an economic point of view, since periwinkles and mussels are commercially exploited in Ireland. [ABSTRACT FROM AUTHOR]

The reproductive cycles of four limpet species, Patella depressa, Patella ulyssiponensis, Patella vulgata and Patella rustica are described for several locations in northern and central Portugal. Patella depressa and P. ulyssiponensis displayed almost continual gonad activity, with two main spawning periods, September–January and March–June, and minor spawning events dispersed throughout the year. Patella vulgata and P. rustica exhibited highly synchronized reproductive cycles, with well-defined breeding and resting periods. Gonad development in P. vulgata started in September and spawning took place from November–December to March. In P. rustica development started in June and spawning occurred from September–October to December–January. Compared to the 1980s these results suggest that breeding periods are becoming longer in southern species and shorter in northern species. [ABSTRACT FROM PUBLISHER]

1. On thermally stressful rocky shores, small, slow-moving ectotherms such as limpets exhibit morphological characteristics such as high-spired and heavily ridged shells which may reduce the likelihood of reaching stressful or lethal body temperatures. 2. The effects of shell height and shell surface area on predicted limpet body temperatures were tested with a previously developed heat budget model. The model was parameterized with morphological data from three species ( Lottia gigantea, Patella vulgata and Siphonaria gigas), which differ dramatically in their morphology and in the body temperatures they are likely to reach in the field. 3. Limpet models and standard cones with higher height : length ratios lost heat to convection more readily than models with lower spired shells. 4. Heavily ridged shells lost heat to convection more readily than smoother shells, but this effect was only pronounced at high wind velocities. 5. When the heat budget model parameters were applied to a real environmental data set, the model predicts that maximum body temperatures and cumulative thermal stress vary among species. These differences are related primarily to the height : length ratio of the shell, and to a lesser extent to the presence of ridges. 6. These results suggest that some intra- and interspecific variation in limpet morphology may be phenotypic or evolutionary responses to variation in environmental temperatures. Our findings are supported by observed patterns of limpet morphological variation across natural thermal gradients. [ABSTRACT FROM AUTHOR]

Abstract: The fast increase of anthropogenic activities has led to a continual influx of xenobiotics into the marine ecosystems. Quantifying biochemical parameters in marine invertebrates makes possible the evaluation of pollutants’ damaging effect. In fact, to examine the health state of Tangier''s bay, we focused on the study of catalase, esterase, acetylcholinesterase and α-amylase activities as biomarkers in two species of marine invertebrates Nereis diversicolor (Polychaeta, Nereidae) and Patella vulgata (Mollusca, Prosobranchia), collected from different sites along the Mediterranean coastline of Tangier. Our results showed that these biochemical parameters are disturbed following the level of decreasing environmental quality, and for this reason they are promising in the biomonitoring studies of the Moroccan marine environment. [Copyright &y& Elsevier]

Biodiversity is defined by the scales at which organisms coexist. Coexistence at larger spatial scales may be underpinned by segregation at smaller spatial scales or temporal variability in behaviour and/or distribution. Limpets of the genus Patella are keystone grazers controlling the growth of macro-algae on many rocky shores. This study examined the distribution and abundance of P. vulgata and P. ulyssiponensis in relation to habitat and to each other at a range of spatial scales. Limpets were sampled on four shores on each of the east and west coasts of Ireland, in two different transects (10 m apart) at each of three shore heights in winter 2003 and summer 2004. P. vulgata and P. ulyssiponensis coexist around the coast of Ireland, but on shores where they co-occur, the pattern of coexistence begins to break down at the level of shore height: P. ulyssiponensis were more abundant on the low-shore than mid-shore, and P. vulgata were distributed evenly throughout the low and the mid-shore. At the level of habitat (pools vs. open rock), the two species exhibited a high degree of segregation: P. vulgata of all sizes were more common on open rock and P. ulyssiponensis of all sizes were more common in pools. The presence or absence of P. ulyssiponensis had no effect on the distribution of juvenile P. vulgata with respect to pools. Unexpectedly, however, a greater proportion of adult P. vulgata were found in pools at sites where P. ulyssiponensis were present in the pools than at sites where they were absent. The results of this study emphasize the need for multiple-scale analyses of the distribution and abundance of organisms to understand the organisation of natural assemblages. [ABSTRACT FROM AUTHOR]

Abstract: The characteristic variability of grazing has potential consequences for intertidal productivity and community structure, particularly as many of the underlying functional relationships are thought to be non linear. As a first approximation, it can be hypothesised that grazing is patchy over short time periods before a more uniform coverage is established over longer time scales. This prediction is supported by relatively short term observations previously made of limpet foraging. We used eight arrays of wax disks on each of four shores to test the hypothesis that grazing is patchy in the short term, but that this pattern is lost as the pattern of grazing averages out over longer time scales. Wax disk arrays were exposed for two weeks at a time for a period of six weeks in 2001 and in 2002 using the same set of disk holes each time. Grazing at the same disk location could therefore be measured over two weeks and over longer periods by averaging successive deployments. We used all three successive deployments to estimate the average grazing at each disk location over a six week period in 2001 and 2002. All six deployments were used to characterise the pattern of grazing at longer time scales. The spatial pattern of grazing in arrays was summarized using semivariogram analyses. For two-week deployments, the average standardized semivariance of grazing for disks separated by 20 cm was less than one. This pattern implies spatial autocorrelation of grazing at this scale. There was no support for the hypothesis that small scale patchiness in grazing would disappear over time. The average strength of spatial autocorrelation increased when data were integrated over longer periods. A preliminary analysis indicated that the degree of autocorrelation within arrays increased with grazing intensity at short time scales. Surface roughness disrupted autocorrelation of grazing over both short and long time scales. The persistent patchiness of grazing is likely to have implications for biofilm productivity, particularly on smoother shores. [Copyright &y& Elsevier]