Myxozoans as biological tags for stock identification of the Argentine hake, Merluccius hubbsi (Gadiformes: Merlucciidae)

SUMMARYMyxozoans have been successfully used as tags for fish stock identification around the world. However, few studies using myxozoan tags have been carried out in the Southern Atlantic, a region with complex oceanography that constitutes a potentially suitable scenario for testing the utility of myxozoans as indicators. Its usefulness was tested using six samples of Merluccius hubbsi in two different regions of the Argentine Sea. Generalized linear models were performed to assess the effects of fish size and sex, and year and region of capture and selected using the Information Theoretic approach. Three myxozoan species were recorded: Kudoa rosenbuschi, Myxoproteus meridionalis and Fabespora sp. Results of modelling species individually showed differential capabilities for detecting geographical population structure at different spatial scales, with K. rosenbuschi and Fabespora sp. allowing the discrimination of northern and southern stocks, but Fabespora sp. also as a promissory indicator of intrapopulation sub-structure due to different migratory routes during non-reproductive periods. This work confirms that myxozoans offer a set of suitable markers at different spatial scales, which can be selected individually or in any combination, depending on the geographical extent of the study, constituting tools adaptable to the objectives of further research on fish population structure.

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Integrating Anisakis spp. parasites data and host genetic structure in the frame of a holistic approach for stock identification of selected Mediterranean Sea fish species

Parasitology ◽

10.1017/s0031182014001103 ◽

2014 ◽

Vol 142 (1) ◽

pp. 90-108 ◽

Cited By ~ 17

Author(s):

S. MATTIUCCI ◽

R. CIMMARUTA ◽

P. CIPRIANI ◽

P. ABAUNZA ◽

B. BELLISARIO ◽

...

Keyword(s):

Mediterranean Sea ◽

Stock Assessment ◽

Spatial Scales ◽

Holistic Approach ◽

Fish Population ◽

Fish Host ◽

Fish Stock ◽

Stock Identification ◽

Fish Stocks ◽

Fish Stock Assessment

SUMMARYThe unique environment of the Mediterranean Sea makes fish stock assessment a major challenge. Stock identification of Mediterranean fisheries has been based mostly from data on biology, morphometrics, artificial tags, otolith shape and fish genetics, with less effort on the use of parasites as biomarkers. Here we use some case studies comparing Mediterranean vs Atlantic fish stocks in a multidisciplinary framework. The generalized Procrustes Rotation (PR) was used to assess the association between host genetics and larval Anisakis spp. datasets on demersal (hake) and pelagic (horse mackerel, swordfish) species. When discordant results emerged, they were due to the different features of the data. While fish population genetics can detect changes over an evolutionary timescale, providing indications on the cohesive action of gene flow, parasites are more suitable biomarkers when considering fish stocks over smaller temporal and spatial scales, hence giving information of fish movements over their lifespan. Future studies on the phylogeographic analysis of parasites suitable as biomarkers, and that of their fish host, performed on the same genes, will represent a further tool to be included in multidisciplinary studies on fish stock structure.

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Habitat selection by nesting and brood-rearing sharp-tailed grouse

Canadian Journal of Zoology ◽

10.1139/z09-016 ◽

2009 ◽

Vol 87 (4) ◽

pp. 326-336 ◽

Cited By ~ 6

Author(s):

Alicia D. Goddard ◽

Russell D. Dawson ◽

Michael P. Gillingham

Keyword(s):

Spatial Scales ◽

Conditional Logistic Regression ◽

Habitat Type ◽

Theoretic Approach ◽

Information Theoretic ◽

Logistic Regression Models ◽

Brood Rearing ◽

Shrub Steppe ◽

Information Theoretic Approach ◽

Selection Of

Breeding success is a critical component of population stability and is often influenced by the habitats used during the breeding season. Current hypotheses suggest that sharp-tailed grouse ( Tympanuchus phasianellus (L., 1758)) select nest and brood-rearing habitats that provide both lateral and overhead cover to avoid detection by predators. We examined the selection of nesting and brood-rearing habitats of sharp-tailed grouse at three spatial scales (landscape, patch, and site) in northeastern British Columbia using standard and conditional logistic regression models and an information–theoretic approach. At the patch and site scales, our results validate our predictions, as nesting females selected shrub–steppe habitats, greater shrub and grass cover, taller vegetation, and greater residual vegetation compared with random sites. Brood-rearing females selected for agricultural habitats during the early brood-rearing period (0–14 days), but did not show selection of any habitat type or site attribute during the late brood-rearing period (15–49 days). We suggest that the selection of shrub-dominated habitats by nesting females supports the hypothesis that females select sites and habitats that maximize concealment. We further suggest that selection of shrub-dominated habitat is occurring in response to changes in habitat conditions and availability, as natural grassland communities have diminished across the landscape.

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Diagnosing the causes of territory abandonment by the Endangered Egyptian vulture Neophron percnopterus: the importance of traditional pastoralism and regional conservation

Oryx ◽

10.1017/s0030605310000189 ◽

2010 ◽

Vol 44 (3) ◽

pp. 424-433 ◽

Cited By ~ 20

Author(s):

Patricia Mateo-Tomás ◽

Pedro P. Olea

Keyword(s):

Linear Models ◽

Nest Site ◽

Spatial Scales ◽

Conservation Strategies ◽

Theoretic Approach ◽

Prediction Ability ◽

Multi Scale ◽

Egyptian Vulture ◽

Neophron Percnopterus ◽

Scale Models

AbstractIdentifying threats to declining species and prescribing ways of preventing their extinction are basic challenges for biodiversity conservation. We analysed the causes underlying the loss of territories of the Endangered Egyptian vulture Neophron percnopterus in a key population at the north-western edge of its distribution in Europe by developing multi-scale models that combined factors from nest site to landscape. We used generalized linear models and an information-theoretic approach to identify the optimal combination of scales and resolutions that could explain territorial abandonment. Those models combining nest-site and landscape scales considerably improved prediction ability compared to those considering only one scale. The best combined model had a high predictive ability (96.9% of correctly classified cases). Small cliffs at high altitudes in rugged areas with declining livestock (especially of sheep and goats) increased the likelihood of territory abandonment. Our findings highlight the importance of developing region-specific multi-scale models to determine reliably the factors driving territory loss and of designing effective conservation strategies accordingly. Conservation measures for the studied population should be developed at two spatial scales. At the smaller scale it is necessary to closely control nest sites to avoid direct disturbances. At a larger scale it is essential to implement policies that can support traditional pastoralism.

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Predicting the occurrence of the quokka, Setonix brachyurus (Macropodidae:Marsupialia), in Western Australia's northern jarrah forest

Wildlife Research ◽

10.1071/wr06161 ◽

2007 ◽

Vol 34 (3) ◽

pp. 194 ◽

Cited By ~ 15

Author(s):

Matt W. Hayward ◽

Paul J. de Tores ◽

Michael J. Dillon ◽

Peter B. Banks

Keyword(s):

Linear Models ◽

Parameter Estimate ◽

Weight Of Evidence ◽

Theoretic Approach ◽

Age Classes ◽

Jarrah Forest ◽

Explanatory Variables ◽

Model Average ◽

Information Theoretic Approach ◽

Fox Control

The quokka, Setonix brachyurus, is a medium-sized, macropodid marsupial that is endemic to south-western Australia. It has declined markedly in its distribution and abundance since the early 1930s and is listed as vulnerable under IUCN criteria. The presence or absence of quokka populations at 66 sites in the northern jarrah forest of Australia was investigated using generalised linear models (GLM). We hypothesised that fox control and the presence of a mosaic of post-fire seral stages within Agonis linearifolia swamp vegetation were important in predicting the presence of quokkas. The number of poison meat baits delivered per hectare, the average number of years since the swamps burnt and the number of post-fire age classes within the swamps (mosaic value) were used as explanatory variables. Two models had substantial support (ΔAICc < 2), with the best approximating model including the variables ‘baiting’ and ‘swamp age’, and the second-best model including the additional variable ‘swamp mosaic value’. The two best models had Akaike weights (weight of evidence as being the best model of the data) of 0.465 and 0.308 respectively. We used an information-theoretic approach and multimodel inference to determine the best approximating model of baiting, swamp age and swamp mosaic, and Akaike weights to assess model fit and to rank variable importance. Baiting had a model average parameter estimate of 98, swamp age 79 and a mosaic of swamp age classes 42, implying that baiting was more than twice as important as the number of swamp ages classes at a site in predicting the occurrence of quokkas. Evidence from our analysis therefore supports previous studies that concluded that continued fox control and the maintenance of a mosaic of early seral stage (<10 years since fire) and long unburnt habitat (>19 years since fire) are essential for its conservation.

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Towards an Information-Theoretic Approach to Population Structure

10.29007/268w ◽

2018 ◽

Author(s):

Omri Tal

Keyword(s):

Population Structure ◽

Quantitative Information ◽

Axiomatic Approach ◽

Information Measure ◽

Theoretic Approach ◽

Information Theoretic ◽

Decision Theoretic Approach ◽

Information Theoretic Measures ◽

Source Populations ◽

Information Theoretic Approach

This paper uses an information-theoretic perspective to propose multi-locus informativeness measures for ancestry inference. These measures describe the potential for correct classification of unknown individuals to their source populations, given genetic data on population structure. Motivated by Shannon's axiomatic approach in deriving a unique information measure for communication (Shannon 1948), we first identify a set of intuitively justifiable criteria that any such quantitative information measure should satisfy, and then select measures that comply with these criteria. It is shown that standard information-theoretic measures such as multidimensional mutual information cannot completely account for informativeness when source populations differ in size, necessitating a decision-theoretic approach.

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