Search results for "ards"
showing 10 items of 1705 documents
The intestinal helminth community of the spiny-tailed lizard Darevskia rudis (Squamata, Lacertidae) from northern Turkey
2015
AbstractPopulations of the lizard Darevskia rudis (Bedriaga, 1886) from northern Anatolia were examined for intestinal parasites in adult specimens. One cestode, Nematotaenia tarentolae López-Neyra, 1944 and four nematode species, Spauligodon saxicolae Sharpilo, 1962, Skrjabinelazia hoffmanni Li, 1934, Oswaldocruzia filiformis (Goeze, 1782) and Strongyloides darevskyi Sharpilo, 1976, were found. Three of these nematodes, S. saxicolae, S. hoffmanni and S. darevskyi are suggested to be part of a module in the network of Darevskia spp. and their parasites. Only one, S. darevskyi, was identified as a Darevskia spp. specialist. The very low infection and diversity parameters are indicative of th…
Through the eye of a lizard: hue discrimination in a lizard with ventral polymorphic coloration.
2017
Colour polymorphisms are thought to be maintained by complex evolutionary processes some of which require that the colours of the alternative morphs function as chromatic signals to conspecifics. Unfortunately, a key aspect of this hypothesis has rarely been studied: whether the study species perceives its own colour variation as discrete rather than continuous. The European common wall lizard (Podarcis muralis) presents a striking colour polymorphism: the ventral surface of adults of both sexes may be coloured orange, white, yellow, or with a mosaic of scales combining two colours (orange-white, orange-yellow). Here we use a discrimination learning paradigm to test if P. muralis is capable…
Intensity of male-male competition predicts morph diversity in a color polymorphic lizard.
2017
Sexual selection is one of the main processes involved in the emergence and maintenance of heritable colour polymorphisms in a variety of taxa. Here we test whether the intensity of sexual selection, estimated from population sex ratio, predicts morph diversity in Podarcis muralis, a colour polymorphic lizard with discrete white, yellow, orange, white-orange, and yellow-orange male and female phenotypes (i.e. morphs). In a sample of 116 Pyrenean populations and 5421 lizards, sex ratios (m/f) vary from 0.29 to 2.5, with the number of morphs for each sex ranging from 2 to 5. Male-biased sex ratios are associated with increased morph diversity as measured with Shannon's diversity index. The ma…
Intestinal parasites of unisexual and bisexual lizards Darevskia spp. (Lacertidae) from Northeastern Anatolia
2016
Summary Four bisexual and two unisexual species of the lizard genus Darevskia from northeastern Anatolia were searched for intestinal parasites in adult specimens. One cestode, Nematotaenia tarentolae, and two nematode species, Spauligodon saxicolae and Strongyloides darevskyi, were found, the latest identified as a Darevskia specialist. No major differences between host species were recorded. The very low infection rates and diversity result in depauperate helminth communities for all these lacertid lizards being the lowest among the Palaearctic saurians. Patterns of these helminth communities are compared with those observed in other lacertid lizards from Anatolia and Europe.
The evolution of colour pattern complexity: selection for conspicuousness favours contrasting within-body colour combinations in lizards.
2015
Many animals display complex colour patterns that comprise several adjacent, often contrasting colour patches. Combining patches of complementary colours increases the overall conspicuousness of the complex pattern, enhancing signal detection. Therefore, selection for conspicuousness may act not only on the design of single colour patches, but also on their combination. Contrasting long- and short-wavelength colour patches are located on the ventral and lateral surfaces of many lacertid lizards. As the combination of long- and short-wavelength-based colours generates local chromatic contrast, we hypothesized that selection may favour the co-occurrence of lateral and ventral contrasting patc…
Colour variation and alternative reproductive strategies in females of the Common lizard Lacerta vivipara
2007
Within-sex colour variation is a widespread phenomenon in animals that often plays a role in social selection. In males, colour variation is typically associated with the existence of alternative reproductive strategies. Despite ecological conditions theoretically favourable to the emergence of such alternative strategies in females, the social significance of colour variation in females has less commonly been addressed, relative to the attention given to male strategies. In a population of the common lizard, females display three classes of ventral colouration: pale yellow, orange and mixed. These ventral colours are stable through individual's life and maternally heritable. Females of dif…
A Marine Spatial Planning Approach to Minimize Discards: Challenges and Opportunities of the Landing Obligation in European Waters
2018
A sensible approach to minimize discards is to avoid areas or seasons where unwanted catch may be present. The implementation of a Marine Spatial Planning (MSP) approach to discard management requires the understanding of marine biological processes, as well as fishing conditions at a defined spatial scale. Mathematical models that analyze the spatio-temporal conditions of selected fishing areas allow the definition of different scenarios where discards are minimized by avoiding fishing for unwanted species and/or illegal specimens. Here we show some examples of how particular spatial models can be used for advice on MSP for discards. We introduce a geoserver GIS platform developed to produ…
Integrating spatial management measures into fisheries: The Lepidorhombus spp. case study
2020
Most fisheries management systems rely on a set of regulatory measures to achieve desired objectives. Controls on catch and effort are usually supplemented with gear restrictions, minimum landing sizes, and in the framework of the new common fisheries policy, limitation of discards and by-catch. However, the increasing use of spatial management measures such as conservation areas or spatial and temporal area closures faces new challenges for fishery managers. Here we present an integrated spatial framework to identify areas in which undersized commercial species are more abundant. Once these areas are identified they could be avoided by fishers, minimizing the fishing impact over the immatu…
Discard ban: A simulation-based approach combining hierarchical Bayesian and food web spatial models
2020
12 pages, 6 figures, 6 tables, 2 appendixes, supplementary data https://doi.org/10.1016/j.marpol.2019.103703
The ability of fish ecolabels to promote a change in the sustainability awareness
2021
Abstract Researchers, environmentalists, as well as fisheries and retailers, have been focusing their attention on the design, use and effects that fish ecolabels have on sustainability. The fish processing industry and large retailers have rapidly adopted several market-based standards, with consequences for two major stakeholders: fishermen and consumers. Although the standards have shown rather positive results, from the perspectives of marine biodiversity conservation, the fish industry and trade, it is not clear how they are able to support a change in people’s awareness about sustainability. For this reason, the present work reviews and analyses the literature, produced in the last te…