Julien Chopelet

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The concept of effective population size (Ne) was developed under a discrete-generation model, but most species have overlapping generations. In the early 1970s, J. Felsenstein and W. G. Hill independently developed methods for calculating Ne in age-structured populations; the two approaches produce the same answer under certain conditions and have(More)
The aim of this study was to evaluate the effect of temperature on growth and aerobic metabolism in clones of Daphnia magna from different thermal regimes. Growth rate (increment in size), somatic juvenile growth rate (increment in mass), and oxygen consumption were measured at 15 and 25 degrees C in 21 clones from one northern and two southern sites. There(More)
Large variance in reproductive success is the primary factor that reduces effective population size (Ne) in natural populations. In sequentially hermaphroditic (sex-changing) fish, the sex ratio is typically skewed and biased towards the 'first' sex, while reproductive success increases considerably after sex change. Therefore, sex-changing fish populations(More)
As a result of the global decline of fish stocks, an increasing number of fish species are becoming targets of heavy exploitation, often concomitantly with a lack of biological knowledge on their structure and demographics. Here we present 11 new polymorphic microsatellite loci, isolated from the slinger sea bream (Chrysoblephus puniceus, Sparidae), a(More)
Sandbanks are marine habitats of conservation importance under the EU Habitats Directive. These habitats are becoming subject to impacts of several human activities including fishing, aggregation extraction, and construction of offshore wind farms that may have detrimental effects on their structure and functioning. We characterised and compared the(More)
Fisheries are known to selectively remove larger and older individuals from wild populations. In sequential hermaphrodites, size-selectivity also becomes ‘sex-selectivity’, as the largest and oldest individuals of a sex-changing population primarily belong to one sex. Plasticity in size-at-sex-change is believed to circumvent the undesirable effects of(More)
Sequentially hermaphroditic fish change sex from male to female (protandry) or vice versa (protogyny), increasing their fitness by becoming highly fecund females or large dominant males, respectively. These life-history strategies present different social organizations and reproductive modes, from near-random mating in protandry, to aggregate- and(More)
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