Age and growth of the dusky grouper Epinephelus marginatus (Lowe 1834) in an exploited population of the western Mediterranean Sea
نویسندگان
چکیده
The age and growth of the dusky grouper, Epinephelus marginatus, in the Balearic Islands (western Mediterranean) were studied by otolith analysis from a sample of 358 specimens ranging in total length (LT) from 6 6 to 105 6 cm. The specimens came from commercial artisanal and recreational spear fisheries between 1999 and 2003. Otoliths grew asymmetrically throughout the range of LT studied, showing a clear pattern of alternating translucent and opaque bands. Marginal increment analysis of specimens up to 8 years-old indicated that a single opaque band was formed each year during spring and summer. Whole otoliths allowed ageing specimens up to 10 years old, but above that age whole otoliths yielded lower age estimates than sectioned otoliths. The maximum estimated age was 61 years, which significantly extends the estimated life span of the species from a maximum of 36 years in a previous study. The von Bertalanffy growth parameters were estimated as LN 1⁄4 95 5 cm LT, K 1⁄4 0 087 and TO 1⁄4 1 12. The study revealed differences in mean LT at age and age structure between the shallowand deep-water samples which may be attributed to different fishing pressure and environmental conditions. # 2007 Instituto Español de Oceanografı́a
منابع مشابه
Histological and histochemical study of female germ cell development in the dusky grouper Epinephelus marginatus (Lowe, 1834).
The developmental stages of female germ cells were analysed in a wild population of the protogynous teleost Epinephelus marginatus (Lowe, 1834). 321 wild dusky grouper females were collected in the South Mediterranean Sea during the spawning season and their ovaries analysed using histological and histochemical techniques. Oocyte morphology, nucleus-cytoplasm ratio (N/C) range, location and mov...
متن کاملEcology and ethnoecology of dusky grouper [garoupa, Epinephelus marginatus (Lowe, 1834)] along the coast of Brazil
Dusky grouper (garoupa, Epinephelus marginatus) is an important catch for several artisanal small-scale fisheries along the Brazilian coast. It is a sedentary, monandric, and late maturing protogynous species, which makes it vulnerable to overharvesting even though it is mainly caught through hook and line or spear fishing through free diving. Lack of information on the ecology and biology of t...
متن کاملAn investigation of the health status of wild Libyan dusky grouper, Epinephelus marginatus (Lowe), with characterisation of a new disease, Dusky Grouper Dermatitis (DGD) A THESIS SUBMITTED TO THE UNIVERSITY OF STIRLING FOR THE DEGREE OF DOCTOR OF PHILOSOPHY
متن کامل
Low Connectivity between Mediterranean Marine Protected Areas: A Biophysical Modeling Approach for the Dusky Grouper Epinephelus marginatus
Marine protected areas (MPAs) are major tools to protect biodiversity and sustain fisheries. For species with a sedentary adult phase and a dispersive larval phase, the effectiveness of MPA networks for population persistence depends on connectivity through larval dispersal. However, connectivity patterns between MPAs remain largely unknown at large spatial scales. Here, we used a biophysical m...
متن کاملHelicometrina nimia Linton, 1910 (Digenea: Opecoelidae) in dusky grouper Epinephelus marginatus (Lowe, 1834) (Teleostei: Serranidae) from southeastern Brazil.
Helicometrina nimia (Opecoelidae) is a digenean with wide distribution. Fish families most commonly used as hosts for H. nimia are Serranidae, Pomodasydae, Scorpaenidae and Clinidae. In the present study, a new host and a new host locality are presented for the species. A description of the studied specimens, besides comments concerning its taxonomic status and biometrically compared tables of ...
متن کامل