|
|
|
|
|
| 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 |
| |
|
|
| Du Pontavice, Hubert; Randon, Marine; Lehuta, Sigrid; Vermard, Youen; Savina-rolland, Marie. |
| In fisheries science, a mismatch between the delineation of a fish stock and the underlying biological population can lead to inaccurate assessment and management. Previous results suggested a potential spatial structuration of the Eastern English Channel (EEC) stock of common sole, Solea solea, in three sub-populations. In this article, we propose to investigate the spatial population structure of common sole in the EEC using the von Bertalanffy Growth Function parameters as indicators of population segregation. In order to test the sub-population hypothesis and evaluate its robustness to data sources, we developed three models, all including an area effect on growth parameters. The first model was aimed at testing a potential data source effect (in... |
| Tipo: Text |
Palavras-chave: Key-words; Von Bertalanffy growth function; Stock structuration; Solea solea; Flatfish; Life-history traits; Metapopulation. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00445/55625/57301.pdf |
| |
|
|
| Cormon, Xochitl; Ernande, Bruno; Kempf, Alexander; Vermard, Youen; Marchal, Paul. |
| North Sea saithe Pollachius virens, a major top predator in the area, supports the fishery economy of several European countries. However, recent stock assessments suggested a decrease in spawning stock biomass along with a decline in saithe mean weight-at-ages. In this context, we investigated North Sea saithe growth characteristics at the population level. First, saithe annual weight increments and age-length relationships were studied. Modelling of saithe age-length relationships was carried out using (1) the traditional von Bertalanffy growth function model, (2) the Verhulst logistic model and (3) an empirical linear model. Second, the effects of environmental factors on saithe growth were investigated. Explanatory environmental factors included food... |
| Tipo: Text |
Palavras-chave: Bottom-up processes; Von Bertalanffy growth function; Logistic growth; Norway pout; Prey availability effects; Density-dependence; Predator-prey interactions; Resource limitation; Competition. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00314/42499/41875.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 |
| |
|
|
|
