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Lagardere, Françoise; Troadec, Herve. |
Close similarities have been found between the otoliths of sea-caught and laboratory-reared larvae of the common sole Solea solea (L.), given appropriate temperatures and nourishment of the latter. But from hatching to mouth formation. and during metamorphosis, sole otoliths have proven difficult to read because the increments may be less regular and low contrast. In this study, the growth increments in otoliths of larvae reared at 12 degrees C were counted by light microscopy to test the hypothesis of daily deposition, with some results verified using scanning electron microscopy (SEM), and by image analysis in order to compare the reliability of the 2 methods in age estimation. Age was first estimated (in days posthatch) from light micrographs of whole... |
Tipo: Text |
Palavras-chave: Larval sole; Solea solea; Otolith; Daily increment; Validation; Image analysis. |
Ano: 1997 |
URL: http://archimer.ifremer.fr/doc/00337/44785/44488.pdf |
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Edeyer, Anaick; De Pontual, Helene; Payan, P; Troadec, Herve; Severe, Armelle; Mayer-gostan, N. |
We studied the circadian variations of the ionic composition ([Na+], [K+], [Cl-]), total CO2 ([tot CO2]), and protein concentration ([protein]) in the plasma and endolymph in the distal and proximal sides of the sacculus in the turbot Psetta maxima. Daily variations in total plasma calcium ([tot Ga]) were also recorded. Significant diurnal fluctuations occurred in most parameters and the spatial heterogeneity of the endolymph composition was maintained throughout a 24 h period. The main parameters implicated in otolith calcification, endolymph [tot CO2] and endolymph [protein], fluctuated diurnally, [tot CO2] was highest and [protein] lowest at night; the relative concentrations were reversed during the day. The inverse, alternating relationship of maximal... |
Tipo: Text |
Palavras-chave: Daily cycle; Endolymph; Otolith; Chemical composition; Teleost. |
Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/00000/10572/7603.pdf |
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Troadec, Herve. |
A method to assist the reading of calcified structures with digital images is proposed. An a priori growth pattern is introduced in the image processing to take into account both the variability of the ring size and the non-linearity of their growth. The introduction of biological knowledge is performed within a demodulation processing using the reciprocal growth function. The ring number is estimated by spectral analysis. The constraints introduced by the growth model are weak since they are restricted to the definition of L0, in the case of an exponential model, or of L∞ in the case of a Von Bertalanffy model. When applied to larval Dover sole otoliths (Solea solea) results close to the expert's are obtained. In the case of saithe otoliths (Pollachius... |
Tipo: Text |
Palavras-chave: Otolithe; Image numérique; Âge; Croissance; Solea solea / Pollachius virens; Otolith; Digital image; Age; Growth; Solea solea / Pollachius virens. |
Ano: 1991 |
URL: http://archimer.ifremer.fr/doc/00189/30072/28560.pdf |
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Baglinière, J. L.; Bomassi, P.; Bousquet, B.; Chancerel, F.; De Pontual, Helene; Dumas, J.; Euzenat, G.; Fontenelle, G.; Fournel, F.; Gayou, F.; Luquet, J. F.; Maisse, G.; Martin Ventura, J. A.; Marty, A.; Nihouarn, A.; Porcher, J. P.; Prevost, E.; Prouzet, Patrick; Pustelnik, G.; Richard, A.; Troadec, Herve. |
This report confirms interpretation criteria used in scale reading for age determination of Atlantic Salmon in freshwater and in sea water with typical examples. The difficulties for age determination of wild and reared populations by showing atypical examples are presented. Finally some recommandations to a better knowledge of Atlantic salmon population in south distribution area are proposed. |
Tipo: Text |
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Ano: 1985 |
URL: https://archimer.ifremer.fr/doc/00480/59127/61755.pdf |
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Panfili, Jacques; De Pontual, Helene; Troadec, Herve; Wrigh, Peter J.. |
Sclerochronology, the study of calcified structures to reconstruct the past history of living organisms, is central to fish biology and fisheries management. This manual aims to provide an overview of the current theoretical and practical aspects of sclerochronological studies. By providing information on the nature of calcified structures (otoliths, scales, skeleton), their uses in fish research and methods for preparation and examination, the manual constitutes a comprehensive guide for researchers, technicians and students either new to the field or interested in expanding their range of expertise. The enclosed multimedia version (DVD) is supplemented by videos illustrating the main technical procedures with an alternative navigation mode based on... |
Tipo: Text |
Palavras-chave: Age; Age determination; Biological aging; Chemistry; Growth; Otolith reading; Otoliths; Scale reading; Scales; Skeleton. |
Ano: 2002 |
URL: http://archimer.ifremer.fr/doc/00017/12801/9742.pdf |
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Latrouite, Daniel; Antoine, Loic; Cosson, Nathalie; Danel, Patrick; Desaunay, Yves; Dupouy, Herve; Galgani, Francois; Lorance, Pascal; Morandeau, Fabien; Morizur, Yvon; Rivoalen, Jean-jacques; Sacchi, Jacques; Troadec, Herve. |
The scientific cruise Observhal96 took place in August 4-27, 1996 with the underwater system for exploration and intervention « Cyana » and the support vessel « Suroît ». The goal of this IFREMER first use of a man opereted submersible for a fisheries study was to observe fishes and invertebrates in their environment, as well as fishing gears in operation. All the dives, 2 to 5 hours long, took place off Brittany in Atlantic. Five were shalower than 100 meters, nine between 100 and 200 meters, one at 400 meters and for deeper than 1000 meters. Six dives have been dedicated to in situ study of the impact of fishing gears : observation of the geometry of a monkfish tramel net and analysis of losses during hauling ; tracks of a bottom trawl and relative... |
Tipo: Text |
Palavras-chave: Fish behaviour; Fishery ecology; Submarine Cyana; Dive; Underwater observation; Comportement des poissons et invertébrés; Ecologie halieutique; Submersible Cyana; Observation sous marine. |
Ano: 1996 |
URL: http://archimer.ifremer.fr/doc/1996/rapport-1554.pdf |
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