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showing 10 items of 487 documents
Distribution of sea urchins living near shallow water CO2 vents is dependent upon species acid-base and ion-regulatory abilities.
2013
To reduce the negative effect of climate change on Biodiversity, the use of geological CO2 sequestration has been proposed; however leakage from underwater storages may represent a risk to marine life. As extracellular homeostasis is important in determining species' ability to cope with elevated CO2, we investigated the acid-base and ion regulatory responses, as well as the density, of sea urchins living around CO2 vents at Vulcano, Italy. We conducted in situ transplantation and field-based laboratory exposures to different pCO2/pH regimes. Our results confirm that sea urchins have some ability to regulate their extracellular fluid under elevated pCO2. Furthermore, we show that even in cl…
Modelling the effects of more selective trawl nets on the productivity of European hake (Merluccius merluccius) and deep-water rose shrimp (Parapenae…
2018
Single-species Gadget models were used to assess the effects of using a sorting grid mounted on the traditional trawl net used by Sicilian trawlers to exploit the deep-water rose shrimp in the Strait of Sicily. The main commercial by-catch species of this fleet is the European hake (Merluccius merluccius), often caught at sizes well below the minimum conservation reference size. Selectivity curves based on the results of an experimental survey carried out in the area using a commercial trawler equipped with an ad hoc-designed sorting grid were incorporated into single-species Gadget models to forecast the effects of changing fishery selectivity on the performance of the two stocks in terms …
Cuticular hydrocarbons as potential mediators of cryptic species divergence in a mutualistic ant association
2019
International audience; Upon advances in sequencing techniques, more and more morphologically identical organisms are identified as cryptic species. Often, mutualistic interactions are proposed as drivers of diversification. Species of the neotropical parabiotic ant association between Crematogaster levior and Camponotus femoratus are known for highly diverse cuticular hydrocarbon (CHC) profiles, which in insects serve as desiccation barrier but also as communication cues. In the present study, we investigated the association of the ants' CHC profiles with genotypes and morphological traits, and discovered cryptic species pairs in both genera. To assess putative niche differentiation betwee…
Genome sequence of the pea aphid Acyrthosiphon pisum
2010
The genome of the pea aphid shows remarkable levels of gene duplication and equally remarkable gene absences that shed light on aspects of aphid biology, most especially its symbiosis with Buchnera.
Spatial heterogeneity of spring phytoplankton in a large tropical reservoir: could mass effect homogenize the heterogeneity by species sorting?
2018
Reservoirs are river–lake hybrid ecosystems characterized by a marked longitudinal zonation and variable flushing rates depending on the use of stored waters. The structure of their phytoplankton is therefore subjected to the interplay between the environmental conditions of the different zones (species sorting) and the strength of the unidirectional flow (mass effect). The spatial distribution of spring phytoplankton was investigated in a tropical reservoir across its different zones. Phytoplankton displayed heterogeneous spatial patterns from the turbulent, nutrient-rich riverine zones to the relatively stable lacustrine zone. The analysis of this spatial heterogeneity revealed the relati…
Characterization of the biodegradation, bioremediation and detoxification capacity of a bacterial consortium able to degrade the fungicide thiabendaz…
2017
Thiabendazole (TBZ) is a persistent fungicide used in the post-harvest treatment of fruits. Its application results in the production of contaminated effluents which should be treated before their environmental discharge. In the absence of efficient treatment methods in place, biological systems based on microbial inocula with specialized degrading capacities against TBZ could be a feasible treatment approach. Only recently the first bacterial consortium able to rapidly transform TBZ was isolated. This study aimed to characterize its biodegradation, bioremediation and detoxification potential. The capacity of the consortium to mineralize 14C-benzyl-ring labelled TBZ was initially assessed. …
Harvesting changes mating behaviour in European lobster
2018
Removing individuals from a wild population can affect the availability of prospective mates and the outcome of competitive interactions, with subsequent effects on mating patterns and sexual selection. Consequently, the rate of harvest‐induced evolution is predicted to be strongly dependent on the strength and dynamics of sexual selection, yet there is limited empirical knowledge on the interplay between selective harvesting and the mating systems of exploited species. In this study, we used genetic parentage assignment to compare mating patterns of the highly valued and overexploited European lobster (Homarus gammarus) in a designated lobster reserve and nearby fished area in southern Nor…
Size-assortative pairing in Gammarus pulex (Crustacea: Amphipoda): a test of the prudent choice hypothesis.
2010
6 pages; International audience; Positive assortative mating is a widespread phenomenon in the animal kingdom. Several hypotheses have been proposed to explain this reproductive pattern in natural populations, but growing evidence suggests that assortative mating most often results from sexual mating preferences. Recently, conditiondependent mate choice in the face of costly competition for mates has been proposed to explain assortative mating in natural populations. Variation in competitive ability may generate variation in both the strength and the direction of mate preference, resulting in assortative mating with respect to individual quality if low-quality competitors are less choosy, o…
Influence of female moulting status on pairing decisions and size‐assortative mating in amphipods
2012
8 pages; International audience; Precopulatory mate guarding is a common strategy, which has evolved in species where the female receptivity (and thus egg fertilization) is predictable, but also limited to a short period. Although males are larger than females in many amphipods, the largest males pair with the largest females, leading to a positive sizeassortative pairing. Size-assortative pairing has received much attention but how moulting physiology could affect pairing decisions has rarely been studied. Here, we tested the hypothesis that the size-assortative pairing in the freshwater amphipod Gammarus pulex is closely related to the female moult cycle. We characterized moulting status …
Assortative mating by size without a size-based preference: the female-sooner norm as a mate-guarding criterion.
2013
7 pages; International audience; The study of size-assortative mating, or homogamy, is of great importance in speciation and sexual selection. However, the proximate mechanisms that lead to such patterns are poorly understood. Homogamy is often thought to come from a directional preference for larger mates. However, many constraints affect mating preferences and understanding the causes of size assortment requires a precise evaluation of the pair formation mechanism. Mate-guarding crustaceans are a model group for the study of homogamy. Males guard females until moult and reproduction. They are also unable to hold a female during their own moult and tend to pair with females closer to moult…