Search results for "group"
showing 10 items of 19225 documents
Paleohistological estimation of bone growth rate in extinct archosaurs
2012
The clade Archosauria contains two very different sister groups in terms of diversity (number of species) and disparity (phenotypic variation): Crurotarsi (taxa more closely related to crocodiles than to birds) and Ornithodira (pterosaurs and dinosaurs including birds). The extant species of Crurotarsi may constitute a biased sample of past biodiversity regarding growth patterns and metabolic rates. Bone histological characters can be conserved over hundreds of millions of years in the fossil record and potentially contain information about individual age at death, age at sexual maturity, bone growth rates, and basal metabolic rates of extinct vertebrates. Using a sample of extant amniotes,…
EST based phylogenomics of Syndermata questions monophyly of Eurotatoria
2008
Abstract Background The metazoan taxon Syndermata comprising Rotifera (in the classical sense of Monogononta+Bdelloidea+Seisonidea) and Acanthocephala has raised several hypotheses connected to the phylogeny of these animal groups and the included subtaxa. While the monophyletic origin of Syndermata and Acanthocephala is well established based on morphological and molecular data, the phylogenetic position of Syndermata within Spiralia, the monophyletic origin of Monogononta, Bdelloidea, and Seisonidea and the acanthocephalan sister group are still a matter of debate. The comparison of the alternative hypotheses suggests that testing the phylogenetic validity of Eurotatoria (Monogononta+Bdel…
Behavioural responses of fish groups exposed to a predatory threat under elevated CO2
2019
Most of the studies dealing with the effects of ocean acidification (OA) on fish behaviour tested individuals in isolation, even when the examined species live in shoals in the wild. Here we evaluated the effects of elevated CO2 concentrations (i.e. ∼900 μatm) on the shelter use and group cohesion of the gregarious damselfish Chromis viridis using groups of sub-adults exposed to a predatory threat. Results showed that, under predatory threat, fish reared at elevated CO2 concentrations displayed a risky behaviour (i.e. decreased shelter use), whereas their group cohesion was unaffected. Our findings add on increasing evidence to account for social dynamics in OA experiments, as living in gro…
Consumer perspectives on coastal fisheries and product labelling in France and Italy
2022
Abstract The term ‘coastal fisheries’ designates a form of fishing which is under heavy pressure due to competition by large-scale high sea fishing. Setting up markets for seafood from coastal fisheries might offer possibilities of product differentiation when appreciated by consumers. The aim of this research is to analyse the potential of marketing seafood from coastal fisheries by investigating consumers’ perception of coastal fisheries and their attitudes towards a label for coastal fishery products in France and Italy. This research combined qualitative (focus groups) and quantitative methods (online survey) in two different steps. ‘Coastal fisheries’ were mainly perceived positively, …
Mitochondrial phylogeography of the edible dormouse (Glis glis) in the western Palearctic region
2010
International audience; This study describes in detail the phylogeoraphic pattern Of the edible dormouse (Glis glis) a European rodent With pronounced hibernating behavior We Used sequences of 831 base pairs of the mitochondrial DNA cytochrome-b gene from 130 edible dormice collected at 43 localities (throughout Its distribution. Our results reveal presence of 3 main haplogroups: Sicilian, South Italian (restricted to the Calabrian region) (a widespread lineage corresponding to all remaining western, central. and eastern European populations). Examination of paleontological data confirms refugial regions for G,Its in the 3 Mediterranean peninsulas, although overall low genetic diversity is …
Mechanisms of reciprocity and diversity in social networks: a modeling and comparative approach
2018
Individual-based computer models show that different mechanisms, proximity-based or emotional bookkeeping, can lead to reciprocation. By comparing social networks from different computer models with those of empirical data, we show that the models’ social networks bear limited resemblance with some features of the observed social networks. This indicates that additional social processes (third-party awareness) may be needed in these models to represent more accurately the social behavior and interaction patterns observed in group-living animals.
Revision of the calcareous fen arachnofauna: habitat affinities of the fen-inhabiting spiders
2018
Calcareous fens are one of the most species-rich habitats of the temperate zone of the Northern Hemisphere. In spite of this species richness, however, calcareous fens are still rather poorly investigated. Consequently, the data of the fen-associated spider fauna are also largely lacking. The aim of the research was to study the spider fauna of the calcareous fens of Latvia and to draw conclusions about what kind of spider species and ecological groups typically inhabit calcareous fen habitats. Spiders were sampled in the summer months of 2010, 2011, and 2012 at nine different calcareous fens of the coastal lowland of Latvia. The spider collection was performed by pitfall traps and a sweep …
Understanding insect foraging in complex habitats by comparing trophic levels: insights from specialist host-parasitoid-hyperparasitoid systems
2019
Insects typically forage in complex habitats in which their resources are surrounded by non-resources. For herbivores, pollinators, parasitoids, and higher level predators research has focused on how specific trophic levels filter and integrate information from cues in their habitat to locate resources. However, these insights frequently build specific theory per trophic level and seldom across trophic levels. Here, we synthesize advances in understanding of insect foraging behavior in complex habitats by comparing trophic levels in specialist host-parasitoid-hyperparasitoid systems. We argue that resources may become less apparent to foraging insects when they are member of higher trophic …
Whistle variation in Mediterranean common bottlenose dolphin: The role of geographical, anthropogenic, social, and behavioral factors.
2020
Abstract The studies on the variation of acoustic communication in different species have provided insight that genetics, geographic isolation, and adaptation to ecological and social conditions play important roles in the variability of acoustic signals. The dolphin whistles are communication signals that can vary significantly among and within populations. Although it is known that they are influenced by different environmental and social variables, the factors influencing the variation between populations have received scant attention. In the present study, we investigated the factors associated with the acoustic variability in the whistles of common bottlenose dolphin (Tursiops truncatu…
Consumer acceptance and primary drivers of liking for small fruits
2018
Small fruit grow naturally in northern Italy, but also in the Sicilian region (southern Italy) there are some areas with the essential climatic conditions for the development of this crop. Nevertheless, according to official statistics, the quantities of fresh small fruits placed on the Italian market are lower than in other European countries. The objective of this study was to assess consumer acceptance for sensory attributes and other intrinsic and extrinsic quality parameters of fresh small fruit, in order to know the primary drivers of liking and have a first understanding of reasons for the poor domestic consumption. Six focus groups with sensory test were carried out to assess consum…