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| Flahauw, Emilie; Davenel, Armel; Quellec, Stéphane; Quillien, Virgile; Degremont, Lionel; Lapegue, Sylvie; Hatt, Philippe-jacques. |
| Biological parameters of the cupped oyster Crassostrea gigas such as growth, reproductive effort (duration of the gametogenesis, date of spawning, and fecundity) differ widely among oysters in the same location. Furthermore, most of the traditional methods, like histological observations, could lead to large variability on the observations and the measurements ofthese traits, and large uncertainties on their changes over time. These can be drastically reduced by using Magnetic Resonance Imaging (MRI) which is a non invasive method allowing to measure the same individual during its development. Forty oysters were assessed using MRI for the volume of whole soft body, the intra valves space, the adductor muscle, and the gonad, which also include the digestive... |
| Tipo: Text |
Palavras-chave: Molluscs; Crassostrea gigas; Gonad; Histology; MRI. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00107/21784/19370.pdf |
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| Bugeon, Jerome; Lefevre, Florence; Cardinal, Mireille; Uyanik, Ayhan; Davenel, Armel; Haffray, Pierrick. |
| Rainbow trout with different fillet yield [56 and 65% for low (LY) and high yield (HY), respectively] were examined for muscle organization and flesh quality (instrumental and sensorial evaluations). Both groups had similar body weight (3.6 kg in mean), but the HY group had a higher carcass yield (+15%). Higher total muscle area in the HY group (+20%) was associated with a higher number of muscle fibers (+22%). Flesh of the HY group presented a higher area of myosepta (+10%), fat content (+10%) and luminosity (+6%). Raw fillet mechanical resistance was higher for the HY group; an opposite result was obtained for cooked flesh. Sensorial evaluation of cooked flesh revealed no important differences between groups. Smoked fillet from the HY group presented... |
| Tipo: Text |
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| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00014/12532/9532.pdf |
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| Davenel, Armel; Gonzalez, Ricardo; Suquet, Marc; Quellec, Stephane; Robert, Rene. |
| Previous studies have shown that magnetic resonance imaging is a very appropriate non-invasive technique for quantifying the growth of somatic and gonadic tissues and sex determination in the Pacific oyster, Crassostrea gigas. Despite a thinner gonad, harder to distinguish than that of the Pacific oyster, we showed in this study that it was possible to distinguish and quantify the development of the gonad of the European flat oyster, Ostrea edulis, using a 3D MRI sequence with a suitable finer resolution. Compared to T2-weighted images, theoretically the most appropriate for good anatomical description, T1-weighted images were more suited to gonad observation. The gonad development was quantified by the number of voxels with higher grey level. Larvae were... |
| Tipo: Text |
Palavras-chave: Oyster; Ostrea edulis; Gonad development; Magnetic resonance imaging. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00014/12508/9363.pdf |
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| Hatt, Philippe-jacques; Davenel, Armel; Eliat, Pierre-antoine; Quellec, Stephane. |
| To make a preliminary exploration of the possibilities and limits of magnetic resonance imaging (MRI) for assessing body growth and gonad development of the Pacific oyster, Crassostrea gigas, individual monitoring was conducted on diploid and triploid oysters in their second year, maintained from February to October in a pond on the French Atlantic coast. Magnetic resonance imaging was done on each oyster on five dates during the study period. From these images, variations in the volumes of the flesh, digestive gland-gonad and adductor muscle, and the surface of the gills were measured over time. Apart from the well known differences between diploids and triploids related to maturation of gametes, other original observations of assessing growth were made... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Oyster; Gonad development; Growth; Magnetic resonance imaging; MRI. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6872.pdf |
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| Davenel, Armel; Pouvreau, Stephane; Cambert, Mireille; Suquet, Marc; Mariette, Francois. |
| MR imaging is the most appropriate non-invasive technique for quantifying the growth of somatic and gonad tissues and to determine sex in the Pacific oyster, Crassostrea gigas. However, this technique is too costly for field studies where oysters are used as bioindicators of environmental quality or to be applied routinely in hatcheries. We have tested the ability of low Nuclear Magnetic Resonance relaxometry, a much less expensive technique, to obtain phenotype parameters that can be used to monitor the physiological state of oysters. NMR measurements were carried out at three different periods using a low field spectrometer equipped with a 50 mm diameter probe to investigate 60 oysters in their first year of maturity, which were then dissected to measure... |
| Tipo: Text |
Palavras-chave: Sex identification; Growth; NMR; Crassostrea gigas; Phenotype characterization. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6456.pdf |
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| Davenel, Armel; Quellec, Stéphane; Pouvreau, Stephane. |
| The aim of this study was to test the ability of magnetic resonance imaging (MRI) technique to characterize gonad development and to determine the sex of live Pacific oysters through their shells. A preliminary nuclear magnetic resonance (NMR) retaxometry study was conducted to characterize T-1 and T-2 NMR relaxation parameters for the main oyster organs. This showed that T-1-weighted MRI sequences were most appropriate to optimize contrasts between tissues in images. The results showed that gray levels of gonads in images acquired with gradient-echo sequence were variably affected by T-2* weighting effect. However, the ovaries systematically gave a hypersignal in spin-echo T-1-weighted images, and stack histograms of female oysters showed a peak well... |
| Tipo: Text |
Palavras-chave: Spin echo; Gradient echo; Sex determination; Gonad maturation; Oyster. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1987.pdf |
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