Éditeur(s) : Elsevier
Résumé : Polyploids can be defined as organisms with one or more additional chromosome sets with respect to the number most frequently found in nature for a given species. Triploids, organisms with three sets of homologous chromosomes, are found spontaneously in both wild and cultured populations and can be easily induced in many commercially relevant species of fish and shellfish. The major consequence of triploidy is gonadal sterility, which is of advantage in the aquaculture of molluscs since it can result in superior growth. In fish, the induction of triploidy is mainly used to avoid problems associated with sexual maturation such as lower growth rates, increased incidence of diseases and deterioration of the organoleptic properties. Triploidy can also be used to increase the viability of some hybrids, and is regarded as a potential method for the genetic containment of farmed shellfish and fish. This review focuses on some current issues related to the application of induced polyploidy in aquaculture, namely: 1) the artificial induction of polyploidy and the effectiveness of current triploidisation techniques, including the applicability of tetraploidy to generate auto- and allotriploids; 2) the performance capacity of triploids with respect to diploids; 3) the degree and permanence of gonadal sterility in triploids; and 4) the prospects for the potential future generalised use of triploids to avoid the genetic impact of escapees of farmed fish and shellfish on wild populations. Finally, directions for future research on triploids and their implementation are discussed. (C) 2009 Elsevier B.V. All rights reserved.
Aquaculture (0044-8486) (Elsevier), 2009-08 , Vol. 293 , N. 3-4 , P. 125-156

Droits : 2009 Elsevier Ltd All rights reserved.
http://archimer.ifremer.fr/doc/2009/publication-6648.pdf
DOI:10.1016/j.aquaculture.2009.04.036
http://archimer.ifremer.fr/doc/00000/6648/

Éditeur(s) : HAL CCSD Frontiers Media
Résumé : International audience
The early 2000s marked the end of the Golden age of the antibiotics and the beginning of the awareness on the potential threat to human health due to the dissemination of antimicrobial resistance. As a base-line study, we investigated the antimicrobial susceptibility of 99 strains of non-O1/non-O139 Vibrio cholerae isolated fromwastewater and shellfish in 2000/2001 within La Rance estuary (Brittany, France). All isolates were susceptible to amoxicillin-clavulanic acid, cefotaxime, imipenem, chloramphenicol, nalidixic acid, ciprofloxacin, norfloxacin, amikacin, gentamicin, tetracycline, doxycycline, trimethoprim-sulfamethoxazole, and erythromycin. The only resistances were to streptomycin, sulfonamides and ampicillin: 54.6% of the isolates had acquired resistance to at least one antimicrobial agent among them and only six isolates from cockles were multidrug resistant. On the basis of the distribution of a limited selection of resistance associated genes, our study shows that V. cholerae can constitute an environmental reservoir for these genes. However, none of our isolates harbored integron. This result casts doubt on the capacity of non-O1/non-O139 V. cholerae to acquire resistance-associated genes in such context, and on its potential role of indicator of the dissemination of antimicrobial resistance in the aquatic environment.
ISSN: 1664-302X

hal-01616065
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01616065
DOI : 10.3389/fmicb.2017.01637
PUBMED : 28955305

Éditeur(s) : Elsevier Science Bv
Résumé : We developed a growth model for Crassostrea gigas oyster shells based on the use of in situ temporal manganese markings to calibrate natural cathodoluminescence (CL) changes in the shell hinge sections. A 30 min to 4-h exposure period with Mn2+ (90-120 mg l(-1)) was sufficient to create a detectable mark in the shells. This makes the Mn2+ markings the fastest mollusc shells marking technique to date. The natural CL from juvenile and adult shells cultured in four standard shellfish-farming locations along the English Channel and French Atlantic coasts, exhibited a seasonal pattern (maximum CL intensity occurring during summer periods, minimum CL intensity occurring during winter). Hydrobiological data recorded at Baie des Veys site allows us to attribute the seawater temperature as the main parameter controlling CL of shells. Chlorophyll a and seawater manganese concentration were not decisive in the luminescence intensity of the shells. A relationship between oyster hinge growth and the length of shells makes the umbo investigations a promising tool for oyster-farming and/or wild stock assessments. Shell growth varied at spatial and temporal scales (higher growth rates were observed during summer-autumn and lower during the winter period), depending on seawater temperature changes. Sub-monthly Mn2+ markings support the fact that shell deposition can occur under temperatures below 6 degrees C, which has to be taken into account for both shellfish production and environmental monitoring derived from chemical compositions of the shells. Finally, our results point out the efficiency of age and shell growth rate determination by CL analysis in further shellfish ecosystem researches.
Aquaculture (0044-8486) (Elsevier Science Bv), 2010-02 , Vol. 300 , N. 1-4 , P. 206-217

Droits : 2010 Elsevier B.V. All rights reserved.
http://archimer.ifremer.fr/doc/00002/11300/7912.pdf
DOI:10.1016/j.aquaculture.2009.12.018
http://archimer.ifremer.fr/doc/00002/11300/