14 research outputs found

    Behavioural responses in a congested sea: an observational study on a coastal nest-guarding fish

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    The deleterious effects of anthropogenic noise on animal communication are nowadays recognised, not only in urban environments but also in terrestrial habitats and along coasts and in open waters. Yet, the assessment of short- and long-term exposure consequences of anthropogenic noise in marine organisms remains challenging, especially in fish and invertebrates. Males of the Mediterranean damselfish Chromis chromis vocalise and perform visual displays (multimodal communication) to attract mates. The frequency-range of courtship vocalisations overlaps with low-frequency noise generated by maritime activities, resulting in a reduced detection distance among conspecifics. We quantified the number of courtship-related visual displays performed by males living in areas with different levels of maritime traffic. We also tried to manipulate ambient noise in the field to test male short-term response to increased noise levels. Males living in busier areas (near to a harbour) performed significantly more visual displays than those living in less congested areas. When exposed to artificially-increased ambient noise level (playback of boat noise), males did not adjust the number of visual displays accordingly. Yet, we note how assessing the actual effect of maritime traffic in marine populations in their natural environments is particularly difficult, as the effects of boat noise cannot be easily disentangled from a variety of other intrinsic or environmental factors, discussed in the paper. We thus present suggestions to obtain more robust analyses of variations of courtship behaviours in territorial fishes. We hope this will facilitate a further understanding of the potential long-term effects of anthropogenic noise, whose analyses should be prioritised in the context of environmental impact assessment, resource management and biodiversity conservation

    A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

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    Colonial nesting and the importance of the brood size in male parasitic reproduction of the Mediterranean damselfish Chromis chromis (Pisces: Pomacentridae)

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    We investigated male parasitic spawning in a protected natural population of Mediterranean damselfish. Chromis chromis nested in colonies, inside which males showed a high variability in mating success. Our field observations indicate that the egg batches obtained by the most successful fish were five times bigger than the ones obtained by the less successful fish and many males never received ovipositions. On the other hand, reproductive parasitism was a common tactic within the colony. Successful nesting males sneaked into their neighbours' nests depending on the amount of eggs in their nest, with small clutch size inducing the males to parasitic reproduction. Males failing to receive egg depositions on their nests showed a significantly higher parasitism rate than successful males. Non-territorial males occupied stations in the water column above the breeding grounds and whenever the opportunity arose, they disrupted spawning in progress, stealing copulation with females. We observed that the likelihood of males being parasitized by sneakers was not correlated with the size of their own clutch; on the contrary, it depended both on the number of neighbouring nests and on the number of neighbouring males with barren nests (i.e. unsuccessful males). No correlation was found between parasitic behaviour and male size, suggesting males may switch between spawning in their own and in their neighbour's nests depending on mating opportunity. The hypothesis that colonial nesting facilitates parasitic reproduction is here discussed

    Colonial nesting and the importance of the brood size in male parasitic reproduction of the Mediterranean damselfish Chromis chromis (Pisces: Pomacentridae)

    No full text
    We investigated male parasitic spawning in a protected natural population of Mediterranean damselfish. Chromis chromis nested in colonies, inside which males showed a high variability in mating success. Our field observations indicate that the egg batches obtained by the most successful fish were five times bigger than the ones obtained by the less successful fish and many males never received ovipositions. On the other hand, reproductive parasitism was a common tactic within the colony. Successful nesting males sneaked into their neighbours' nests depending on the amount of eggs in their nest, with small clutch size inducing the males to parasitic reproduction. Males failing to receive egg depositions on their nests showed a significantly higher parasitism rate than successful males. Non-territorial males occupied stations in the water column above the breeding grounds and whenever the opportunity arose, they disrupted spawning in progress, stealing copulation with females. We observed that the likelihood of males being parasitized by sneakers was not correlated with the size of their own clutch; on the contrary, it depended both on the number of neighbouring nests and on the number of neighbouring males with barren nests (i.e. unsuccessful males). No correlation was found between parasitic behaviour and male size, suggesting males may switch between spawning in their own and in their neighbour's nests depending on mating opportunity. The hypothesis that colonial nesting facilitates parasitic reproduction is here discussed

    Protection effects on fish, and comparison of two visual-census techniques in shallow artificial rocky habitats in the northern Adriatic Sea

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    Fish assemblages associated with shallow (4-7 in deep) artificial rocky habitats (i.e. breakwaters) have been assessed between July 2002 and September 2003, at the marine protected a rea of Miramare and adjacent areas outside the reserve (northern Adriatic sea). Our purpose was to: (1) detect possible differences between 'protected vs fished' breakwaters; and (2) compare two visual-census techniques for fish assessment (i.e. strip transects vs stationary points). The fish assemblages observed between protected and fished breakwaters during all four sampling periods were statistically different. More fish taxa were found at the protected than fished breakwaters, while there was no difference in total fish density. Most fish species targeted by fisheries had a greater density (e.g. Sciaena umbra, Dicentrarchus labrax, Sparus aurata, Diplodus vulgaris, Diplodus sargus and Diplodus puntazzo) and/or size (e.g. S. aurata and D. aunularis) at the protected than fished breakwaters. There was a significant difference in fish assemblages due to assessment method. In general, the number of taxa was greater when assessed by strip transects than stationary points. fish density was almost unaffected by the method used, while total density of demersal fish (i.e. excluding schooling species) tended to be greater when evaluated by strip transects, although the difference was statistically significant only in one sampling period out of four. These results indicate that protection from fishing may have the potential to influence fish assemblages associated with breakwaters. Additionally, caution should be used when comparing fish assemblage data collected by different visual assessment techniques

    Monitoring the miramare marine reserve: Assessment of protection efficiency

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    The Miramare Reserve, in the Gulf of Trieste (North Adriatic-Italy), is a small marine protected area (121 hectares) for research, education and conservation and is managed by WWF Italy. Different techniques for taking a qualitative and quantitative census of the fish species, for mapping the nests of Gobius cruentatus, Tripterygion delaisi and Cbromis chromis, for studying the reproductive behaviour of C. cbromis and for measuring the sea ambient noise were used. Visual census techniques were applied in the comparison of two areas which were similar from a morphological point of view, but differed in human activity. © 1998 Taylor & Francis Group, LLC

    Why are many anthropogenic agroecosystems particularly species-rich?

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    Species-rich meadow and pasture habitats are recognised by the European Union Habitats Directive as targets for biodiversity conservation. High species richness is hypothesised to be associated with diversity in plant functional traits and life-history strategies, which are potentially restricted in situations of extremely high and low biomass production. However, variability in functional traits has yet to be investigated across a broad biomass range in nature. We measured variability in a range of functional traits and Grime\u2019s competitor, stress-tolerator, ruderal (CSR) strategies for species comprising lowland meadows, subalpine pastures, abandoned grassland and field margins at sites in northern Italy, alongside peak above-ground biomass. The factor most highly and positively correlated with species richness was strategy richness (the number of CSR strategies; Pearson\u2019s r = 0.864, P , 0.0001, n = 39), followed by variance in traits involved in leaf resource economics and the timing of flowering. Species richness, trait variance and strategy richness were greatest at intermediate biomass. Thus whilst extremes of biomass production were associated with relatively few taxa exhibiting similar trait values and specialised strategies, greater species richness was apparent in meadows and pastures in which species exhibited divergence in resource economics trait values, reproductive timing and strategy richness

    The characteristics of patients with bilateral absent evoked potentials after post-anoxic brain damage: A multicentric cohort study.

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    Patients with bilateral absence of cortical response (N20 <sub>ABS</sub> ) to somatosensory evoked potentials (SSEPs) have poor neurological outcome after cardiac arrest (CA). However, SSEPs are not available in all centers. The aim of this study was to identify predictors of N20 <sub>ABS</sub> . Retrospective analysis of institutional databases (2008-2015) in three ICUs including all adult admitted comatose patients undergoing SSEPs between 48 and 72 h after CA. We collected clinical (i.e. absence of pupillary reflexes, PLR, myoclonus and absent or posturing motor response and myoclonus on day 2-3), electroencephalographic (EEG; i.e. unreactive to painful stimuli; presence of a highly malignant patterns, such as burst-suppression or flat tracings) findings during the first 48 h, and the highest NSE levels on the first 3 days after CA. Unfavorable neurological outcome (UO) was assessed at 3 months using the Cerebral Performance Categories of 3-5. We studied 532 patients with SSEPs, including 143 (27%) without N20 <sub>ABS</sub> ; UO was observed in 334 (63%) patients. Median time to SSEPs was 72 [48-72] h after CA. No patient with absent PLR and myoclonus during the ICU stay had N20 present; similar results were observed with the combination of absent PLR, myoclonus and any EEG pattern (i.e. unreactive or highly malignant). Similar results were observed in the subgroup of patients where NSE was available (n = 303). In a multivariate logistic regression, non-cardiac etiology of arrest, unreactive EEG to painful stimuli, absence of pupillary reflexes and posturing motor response, were independent predictors of N20 <sub>ABS</sub> . When available, the highest NSE was also an independent predictor of N20 <sub>ABS</sub> . Clinical and EEG findings predicting patients with N20 <sub>ABS</sub> , confirm that N20 <sub>ABS</sub> reflects a severe and permanent cerebral damage after CA
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