|
|
|
| Registros recuperados: 22 | |
|
|
| Romdhani, Ahlem; Chater, Ines; Ktari, Mohamed Hédi; Dufour, Jean-louis; Mahe, Kelig. |
| The age of fish in a population is fundamental to most of the questions fishery biologists attempt to answer about that population. The aim of this study was to report the parameters of the weight-length relationship and to estimate the age and growth of Phycis phycis (Linnaeus, 1766) in Gulf of Tunis. A sample of 272 specimens of P. phycis was collected from the landings of the small-scale artisanal fisheries between September 2007 and June 2010. The total length (TL) ranged from 14 to 55.5cm and total weight (TW) from 45 to 1779g. Length-weight relationship were described by allometrically positive for the females (TW = 0.0083*TL3. 0703), males (TW= 0.0063*TL3.1471), and both sexes (TW= 0.0082*TL3. 0759). No significant differences were found between... |
| Tipo: Text |
|
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00117/22790/20592.pdf |
| |
|
|
| Mahe, Kelig; Elleboode, Romain; Persohn, Cecile; Dufour, Jean-louis. |
| Age and growth of lemon sole (Microstomus kitt) were determined from 115 specimens collected in the Celtic Sea and in the North Sea in 2006 and 2007. Total length is ranged from 11 to 44 cm, while total weight varied between 12 and 1040 g. Age estimation was based on otoliths readings. The oldest male and female were estimated to be 9 years old. The length–weight relationships parameters for lemon sole in the Celtic Sea and in the North Sea were W=0.0043*TL3.2860 and W=0.0062*TL3.1505 respectively. Weight including both sexes increased with positive allometric growth. The von Bertalanffy growth equation in the North Sea was fitted on the basis of mean length-at-age data resulting in parameters values of TL∞ = 36.44 cm (S.E. = 0.484), K = 0.187 /y (S.E. =... |
| Tipo: Text |
Palavras-chave: Lemon sole; Growth; Von Bertalanffy; Celtic Sea; North Sea. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00019/13024/10002.pdf |
| |
|
|
| Healey, B.p; Mahe, Kelig; Cossitt, G.; Dufour, Jean-louis; Felix, Jerome; Hicks, H.f.; Hiscock, C.; Schwab, P.. |
| Atlantic cod (Gadus morhua) in NAFO subDivision 3Ps are exploited and jointly managed by Canada and France. Assessments of stock status incorporate age determinations from both countries when dis-aggregating total catches into catch-at-age. An otolith exchange was initiated to evaluate the degree of consistency in the age determinations of Canadian and French personnel. Both graphical and statistical analysis clearly indicate differences in interpretation between Canadian and French readers, with ages assigned by Canadian personnel generally being one-year greater than those of participants from France. However, consistency in age determinations was relatively high within Canada and within France. |
| Tipo: Text |
|
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00035/14627/11905.pdf |
| |
|
|
| Chater, Ines; Romdhani-dhahri, Ahlem; Dufour, Jean-louis; Mahe, Kelig; Chakroun-marzouk, Nadia. |
| The growth and mortality of the brown meagre, Sciaena umbra from the Gulf of Tunis, were investigated using a sample of 276 specimens, ranging from 15.3 to 49.2 cm total length and from 43 to 1565 g total weight. Specimens were collected from artisanal fisheries between October 2008 and September 2011. Otoliths were extracted, thin cross-sections were realized and radii were measured. The log-linear morphometric relationships between total length-total weight and total length-otolith radius were significant (p < 0.05), showed positive allometry (b=3.15) and isometry (b=0.90), respectively. The marginal analysis suggested that only one growth increment was deposited per year. The maximum age of the brown meagre was 22 years for males and 31 years for... |
| Tipo: Text |
Palavras-chave: Brown meagre; Thin otoliths; Growth; Mortality; Gulf of Tunis; Mediterranean Sea. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00424/53552/54415.pdf |
| |
|
|
| Hamed, Oussama; Dufour, Jean-louis; Chakroun-marzouk, Nadia; Mahe, Kelig. |
| Age, growth and mortality of the Starry weever Trachinus radiatus were studied for the first time from 214 individuals collected in the Gulf of Tunis between February 2014 and January 2016. The significant relationship between length-weight was observed for males (a = 0.011, b = 2.992, R2 = 0.981, n = 77) and females (a = 0.010, b = 3.036, R² =0.957, n = 109). Age was estimated by the observation of otoliths transverse thin sections. Age of individuals ranged from 1 to 15 years. The precision was measured by two age estimations from two experts and indicated a good agreement between them (PA = 85.6%, CV = 3.8% and IAPE = 4.1%). The growth parameters of the von Bertalanffy model were TL∞ = 38.41 cm, W∞ = 507.47 g, K = 0.3396 year-1, t0 = 0 year for males... |
| Tipo: Text |
Palavras-chave: Growth; Age; Mortality; Trachinus radiatus; Starry weever; Gulf of Tunis; South-Central Mediterranean Sea. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00477/58905/61467.pdf |
| |
|
|
| Moore, Claire; Lynch, Deirdre; Clarke, Maurice; Officer, Rick; Mills, Jane; Dufour, Jean-louis; Brophy, Deirdre. |
| Sprat is a pelagic species of increasing commercial interest in European waters, yet little is known about its biology or the drivers of its population fluctuations. As a result, the species is currently without an analytical assessment or forecast across much of the North East Atlantic. The objectives of this study were to: verify otolithbased age estimation of sprat; assess the precision, bias and reproducibility of these age estimates; and, determine the age structure of sprat within one North East Atlantic management unit (Celtic Seas ecoregion). Samples were collected over three years (2011, 2013 & 2014) from both commercial catches and scientific surveys. Counts of daily increments in otoliths were used to establish when the first annulus was... |
| Tipo: Text |
Palavras-chave: Sprat; Age verification; Otolith; Marginal increment analysis; Age structure. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00485/59692/62883.pdf |
| |
|
| |
|
| |
|
|
| Mahe, Kelig; Dufour, Jean-louis; Brown, D; Smith, J; Beattie, S; Woods, F. |
| In this working document, the results of an otolith exchange 2016 on Cod (Gadus morhua) in the Celtic Sea are presented. Each year, stock assessment of cod in the Celtic Sea requires data to be compiled and compared. For example the age distribution from this year’s assessment is compared to historical data. In 2016, there has been a small number of one year olds. Consequently, the three main countries (France, Ireland and UK England) which contribute to the cod landings in Celtic Sea organised a small otolith exchange to verify the precision of age data between four readers. Mean precision of age estimate for individual fish had a coefficient of variation (CV) of 0.2% and percent agreement to modal age of 99.5%. There was only one image where two readers... |
| Tipo: Text |
|
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00333/44437/44105.pdf |
| |
|
|
| Souplet, Arnauld; Dufour, Jean-louis. |
| We describe here an improvement of the Lowestoft's method of otoliths readin. This new method is also based on thin sections of otoliths set in black resin, but it allows to prepare a very much greater quantity of otoliths in the same time (between 800 and 1000 otoliths of gadoid fish per day). In the same way, we can now read otoliths very quickly with a great precision and in very good working conditions. [NOT CONTROLLED OCR] |
| Tipo: Text |
|
| Ano: 1983 |
URL: http://archimer.ifremer.fr/doc/1983/rapport-4625.pdf |
| |
|
| |
|
|
| Dufour, Jean-louis; Chantre, Celina; Elleboode, Romain; Mahe, Kelig. |
| Le merlan (merlangius merlangus) est une espèce commerciale importante suivie au niveau européen. La pièce calcifiée utilisée pour l’estimation de l’âge du merlan est l'otolithe. Parmi les 3 paires d'otolithes, ce sont toujours les plus gros, les sagittae qui sont utilisés. Ils conservent la séquence complète des marques de croissance enregistrées (Panfili et al., 2002). Pour observer au mieux ces structures, la technique de coupe transversale a été retenue comme la plus précise (ICES WKARWHG2 REPORT 2016). Les images obtenues sont soumises à l’interprétation par les experts européens. Ce rapport propose de décrire précisément les structures observables sur les images obtenues par la technique de coupe transversale. La variabilité des structures est... |
| Tipo: Text |
Palavras-chave: Merlan; Otolithe; Age; Radiale; Analyse d’images; Croissance. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00627/73941/73376.pdf |
| |
|
| |
|
|
| Romdhani, Ahlem; Ktari, Mohamed-hedi; Dufour, Jean-louis; Mahe, Kelig; Francour, Patrice. |
| Background. The greater forkbeard, Phycis blennoides (Brünnich, 1768), is a gadiform species, which has economical value and its population is dwelling in a 60–800 m depth range throughout the Atlantic and the Mediterranean. Along African north coast, there is a lack of information about the biology (age, growth, sex-ratio) of this species. This study provides the first data on population parameters of P. blennoides in Tunisia. Materials and Methods. Specimens of Phycis blennoides were collected from the landings of the artisanal fisheries between September 2007 and June 2010. The length–weight relations were determined according to the allometric equation: W = aTLb. Growth parameters were estimated using the von Bertalanffy growth equation. Results.... |
| Tipo: Text |
Palavras-chave: Otolith; Biological traits; Length-weight relation; Von Bertalanffy growth function. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00324/43532/43077.pdf |
| |
|
|
| Khoufi, Widien; Dufour, Jean-louis; Jaziri, Hela; Elfehri, Safouene; Elleboode, Romain; Bellamy, Elise; Ben Meriem, Sadok; Romdhane, Mohamed Salah; Mahe, Kelig. |
| Growth parameters of any species are fundamental for biological or dynamic studies. The quality of the estimation for these parameters directly impacts on species stock assessment and, as a consequence, on fisheries management. In order to improve fishery and species stock management, growth analysis, especially by sex, is recommended. In this study, otoliths were used to estimate growth parameters of Merluccius merluccius Rafinesque, 1810. Hake is well-known as being a species in which otolith interpretation is extremely difficult. To estimate growth parameters, the first daily increment was validated as the tool for age determination. Otolith interpretation was done according to the last results of ICES cooperative research report. In total, a sample of... |
| Tipo: Text |
Palavras-chave: Merlucciidae; Merluccius merluccius; Tunisia; Western Mediterranean; Age estimation; Growth model; Otolith. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00191/30238/28662.pdf |
| |
|
|
| Bled--defruit, Geoffrey; Chantre, Celina; Dufour, Jean-louis; Elleboode, Romain; Tribouilloy, Karine; Telliez, Solene; Badts, Vincent; Mahe, Kelig. |
| Ce guide présente les modes et règles de prélèvement puis d'envois des pièces calcifiées dans le cadre de réseaux d’observation coordonnés au niveau international, en particulier au sein du règlement européen sur la collecte des données halieutiques (DCF jusqu'en 2013 puis DCMAP, Data Collection Multi Annual Programme à partir de 2014). Ce guide a pour but de standardiser les prélèvements effectués à l'Ifremer. Il reprend et complète la synthèse française des procédures d'estimation d'âge (Mahé et al., 2009) et le manuel d'utilisation du fichier : "Parametres biologiques v8.xls" (Mahé et al., 2007). Les procédures décrites dans ce guide sont conformes aux référentiels de la base Harmonie de l'Ifremer. |
| Tipo: Text |
|
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00116/22764/64995.pdf |
| |
|
|
| Cresson, Pierre; Rouquette, Manuel; Marco-miralles, Francoise; Dufour, Jean-louis; Causse, Romain; Bouchoucha, Marc; Mahe, Kelig. |
| In June 2015, an individual of Diretmichthys parini (Post and Quero, 1981) was trawled at 530 m depth, in the North Sea off Norway and donated to research. This capture, the first for this species in the North Sea was the northernmost recorded so far, and provided an opportunity to document some aspects of the biology and ecology of this data-poor species. This individual was a female, 331 mm total length of 33 years old, with low mercury content in muscle and liver (~ 0.2 μg g− 1 wet mass). Stable isotope ratios (C and N) in muscle and liver were consistent with the planktonic diet expected for this species. The capture of this fish at the northern latitude known so far would be consistent with the extension of the home range and the latitudinal shift... |
| Tipo: Text |
Palavras-chave: Diretmichthys parini; Diet; North Sea; Latitudinal shift; Mercury. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00357/46805/46977.pdf |
| |
|
|
| Chater, Ines; Romdhani, Ahlem; Dufour, Jean-louis; Mahe, Kelig; Francour, Patrice; Chakroun-marzouk, Nadia. |
| Background. Bastard grunt, Pomadasys incisus (Bowdich, 1825), is reported as a well-established species in the Mediterranean Sea. Although bastard grunt has rapidly expanded its area of distribution in the Mediterranean, there is no information about its age and growth. The aim of this study was to provide data about growth, condition, and first sexual maturity of the species in order to contribute to a better management of its fishery. Materials and methods. A total of 515 specimens of bastard grunt were caught in the Gulf of Tunis. The age was determined from otoliths. Length–weight relation, von Bertalanffy equation, and growth rate were employed to evaluate the fish growth. Also the condition factor and length at first sexual maturity were calculated.... |
| Tipo: Text |
Palavras-chave: Sagittal otoliths; Biological traits; Von Bertalanffy growth function; Length-weight relation; Pomadasys incisus. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00259/37006/35502.pdf |
| |
|
|
| Mahe, Kelig; Dufour, Jean-louis; Mccausland, Ian; Sainza, Maria; Leal, Ana; Gonzalez, Cristina; Elleboode, Romain. |
| In September 2015, the Working Group on Biological Parameters (WGBIOP) recommended the first otolith exchange for Pollachius pollachius in 2016 (Otolith Exchanges proposals for 2016/2017; ICES, 2015). Kélig Mahe (IFREMER, France) was decided to be the responsible to organise this otolith exchange. A total of 5 readers from 2 countries (France & Spain) participated at the exchange of 2016. The otoliths of 314 individuals sampled from 2011 to 2015 in Southern stock (ICES area: IXa; n=99) and in (ICES areas: IVc, VIId, VIIe, VIIj-h; n=215) were used for this exchange. For the Northern stock, the precision values for both stocks were very high but the value for Northern stock (PA=91.6%, CV=3.8%; APE= 0.8%) was higher than this for Southern stock (PA=74.5%,... |
| Tipo: Text |
|
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00351/46200/45899.pdf |
| |
|
|
| Mahe, Kelig; Bellail, Robert; Dufour, Jean-louis; Boiron-leroy, Anne; Dimeet, Joel; Duhamel, Erwan; Elleboode, Romain; Felix, Jerome; Grellier, Patrick; Huet, Jerome; Labastie, Jacques; Le Roy, Didier; Lizaud, Oceann; Manten, Marie-line; Martin, Stephane; Metral, Luisa; Nedelec, Daniel; Verin, Yves; Badts, Vincent. |
| This document presents all the techniques used in routine by Ifremer to estimate the age of fish from the calcified piece. The procedure for estimating age describes each technical stage from the taking of the calcified piece through to the supplying of key sizes/ages to the European work groups. This procedure is specific to each species and even each population of fish. |
| Tipo: Text |
Palavras-chave: Poisson; TNPC; Préparation; Procédure; Age; Ecaille; Illicium; Otolithe; Sclérochronologie; Fish; TNPC; Preparation; Procedure; Age; Scale; Illicium; Otolith; Sclerochronology. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00000/7294/rapport-7294.pdf |
| |
| Registros recuperados: 22 | |
|
|
|
