Search results for " Z"

Following the Antarctic Circumpolar Current: patterns and processes in the biogeography of the limpet Nacella (Mollusca: Patellogastropoda) across th…

2017

14 pages; International audience; AimWe use an integrative biogeographical approach to further understand the evolution of an important Southern Ocean marine benthic element, the limpet genus Nacella (Mollusca: Patellogastropoda).LocationSouthern Ocean.MethodsWe used multi-locus time-calibrated phylogeny of Nacella at the scale of the whole Southern Ocean to elucidate the underlying processes involved in the origin and diversification of the genus.ResultsDivergence-time estimates suggest that soon after its origin during the mid-Miocene (c. 12.5 Ma), Nacella separated into two main lineages currently distributed in (1) South America and (2) Antarctica and the sub-Antarctic islands. We ident…

Woody Plant Declines. What’s Wrong with the Microbiome?

2020

National audience; Woody plant (WP) declines have multifactorial determinants as well as a biological and economic reality. The vascular system of WPs involved in the transport of carbon, nitrogen, and water from sources to sinks has a seasonal activity, which places it at a central position for mediating plant–environment interactions from nutrient cycling to community assembly and for regulating a variety of processes. To limit effects and to fight against declines, we propose: (i) to consider the WP and its associated microbiota as an holobiont and as a set of functions; (ii) to consider simultaneously, without looking at what comes first, the physiological or pathogenic disorders; and (…

Morphological and molecular analysis of Henricia Gray, 1840 (Asteroidea: Echinodermata) from the Northern Atlantic Ocean

2017

The genus Cyclops (Copepoda, Cyclopoida) in Europe

2016

16 páginas, 23 figuras, 1 tabla, información suplementaria.

Females pay the oxidative cost of dominance in a highly social bird.

2018

12 pages; International audience; Understanding the evolution and maintenance of social behaviour requires a better understanding of the physiological mechanisms underlying the trade-offs between the benefits and costs of social status. Social dominance is expected to provide advantages in terms of access to resources and to reproduction but acquiring and maintaining dominance may also entail physiological costs. Dominant individuals are likely to engage more frequently in aggressive behaviours and/or may allocate a substantial amount of energy and resources to signal their status. Hence, dominance is likely to involve multiple physiological processes that stimulate aerobic metabolism and l…

Opportunity costs resulting from scramble competition within the choosy sex severely impair mate choosiness.

2016

12 pages; International audience; Studies on mate choice mainly focus on the evolution of signals that would maximize the probability of finding a good-quality partner. Most models of sexual selection rely on the implicit assumption that individuals can freely compare and spot the best mates in a heterogeneous population. Comparatively few studies have investigated the consequences of the mate-sampling process. Several sampling strategies have been studied from theoretical or experimental perspectives. They belong to two families of decision rules: best-of-n strategies (individuals sample n partners before choosing the best one within this pool) or threshold strategies (individuals sequenti…

No Evidence for Enforced Alloparental Care in a Cooperatively Breeding Parrot

2016

In cooperatively breeding species, in which non-breeding helpers assist in rearing the offspring of breeding individuals, conflicts of interest commonly occur between breeders and helpers over their respective contributions to offspring care. During such conflicts, breeders might use aggressive behavior to enforce contributions of helpers to offspring care, especially if helpers are not related to the breeders and their offspring and thus do not stand to gain indirect fitness benefits by helping. Using a combination of behavioral and genetic data, we investigated in the cooperatively breeding El Oro parakeet Pyrrhura orcesi (i) whether breeders are commonly dominant over helpers, (ii) wheth…

Biological control of potato soft rot caused by Dickeya solani and the survival of bacterial antagonists under cold storage conditions

2018

Dickeya and Pectobacterium are responsible for causing blackleg of plants and soft rot of tubers in storage and in the field, giving rise to losses in seed potato production. In an attempt to improve potato health, biocontrol activity of known and putative antagonists was screened using in vitro and in planta assays, followed by analysis of their persistence at various storage temperatures. Most antagonists had low survival on potato tuber surfaces at 4 °C. The population dynamics of the best low‐temperature tolerant strain and also the most efficient antagonist, Serratia plymuthica A30, along with Dickeya solani as target pathogen, was studied with TaqMan real‐time PCR throughout the stora…

Private information alone can trigger trapping of ant colonies in local feeding optima.

2015

Ant colonies are famous for using trail pheromones to make collective decisions. Trail pheromone systems are characterised by positive feedback, which results in rapid collective decision making. However, in an iconic experiment, ants were shown to become 'trapped' in exploiting a poor food source, if it was discovered earlier. This has conventionally been explained by the established pheromone trail becoming too strong for new trails to compete. However, many social insects have a well-developed memory, and private information often overrules conflicting social information. Thus, route memory could also explain this collective 'trapping' effect. Here, we disentangled the effects of social …

Extended winters entail long-term costs for insect offspring reared in an overwinter burrow

2018

International audience; Winter imposes an ecological challenge to animals living in colder climates, especially if these adverse conditions coincide with reproduction and offspring rearing. To overcome this challenge, some insects burrow in the soil to protect adults, larvae, or eggs from negative effects of winter. However, whether this protection is effective against any long-term consequences of changes in winter duration is unclear. Here, we investigated the long-term effects of winter length variation on eggs of the European earwig Forficula auricularia. In this insect, females construct and maintain a burrow between late autumn and spring, in which they provide extensive forms of care…