Suchergebnisse

Because the meagre (Argyrosomus regius) is not currently found around the Balearic Islands (western Mediterranean), the Balearic government is carrying out a restocking programme to recover its population. The success of this programme is critically dependent on improved knowledge of the meagre's life cycle, and particularly its reproductive biology. Data on key reproductive parameters based on both reared and wild specimens are reported here. Histological examinations and gonadosomatic indices from 342 reared specimens demonstrated that 1) the potential reproductive season ranged from April to June and peaked in May, and 2) length at maturity (L50) was 49.3 cm for males and 57.2 cm for females, age at maturity (A50) was 2.7 years for males and 3.5 years for females, and weight at maturity (W50) was 1396 g for males and 1892 g for females. Histological examinations of 37 wild fish from Cádiz (SW Spain) demonstrated that the meagre has determinate fecundity. The annual potential fecundity of reared females ranged from 0.9 to 4.2 million oocytes, which is exponentially dependent upon female size. ; La corvina (Argyrosomus regius) actualmente no se encuentra en las Islas Baleares (Mediterráneo Occidental) y, por tanto, se están realizando esfuerzos para recuperar su población a través de un programa de repoblación que se está llevando a cabo por el Gobierno Balear. El éxito del programa de recuperación depende fundamentalmente de la mejora de los conocimientos del ciclo de vida de la corvina, y en particular de su biología reproductiva. Este estudio presenta datos sobre los principales parámetros reproductivos de la especie, basándose tanto en ejemplares criados en cautividad como salvajes. Los exámenes histológicos e índices gonadosomáticos de 342 especímenes criados en cautividad demostraron lo siguiente: 1) la potencial época de puesta se extendió de abril a junio y alcanzó su punto máximo en mayo, y 2) la talla de madurez (L50) fue de 49.3 cm para los machos y 57.2 cm para las hembras, la edad de madurez (A50) fue de 2.7 años para los machos y 3.5 años para las hembras, y el peso de madurez (W 50) fue de 1396 g para los machos y 1892 g para las hembras. Los exámenes histológicos de 37 peces salvajes procedentes de Cádiz (SO de España) demostraron que la corvina tiene fecundidad determinada. La fecundidad potencial anual de las hembras criadas en cautividad, la cual está exponencialmente relacionada con el tamaño de la hembra, osciló entre 0.9 y 4.2 millones de ovocitos.

Because the meagre (Argyrosomus regius) is not currently found around the Balearic Islands (western Mediterranean), the Balearic government is carrying out a restocking programme to recover its population. The success of this programme is critically dependent on improved knowledge of the meagre's life cycle, and particularly its reproductive biology. Data on key reproductive parameters based on both reared and wild specimens are reported here. Histological examinations and gonadosomatic indices from 342 reared specimens demonstrated that 1) the potential reproductive season ranged from April to June and peaked in May, and 2) length at maturity (L50) was 49.3 cm for males and 57.2 cm for females, age at maturity (A50) was 2.7 years for males and 3.5 years for females, and weight at maturity (W50) was 1396 g for males and 1892 g for females. Histological examinations of 37 wild fish from Cádiz (SW Spain) demonstrated that the meagre has determinate fecundity. The annual potential fecundity of reared females ranged from 0.9 to 4.2 million oocytes, which is exponentially dependent upon female size. ; This work has been funded by the Plan Nacional de Cría de Corvina 2005-2007 (JACUMAR MAPA-CC.AA.) and by the INIA projects RTA-2007 00033-C02-01 and RTA-2011 00056-C02-00 ; Peer Reviewed

SIMPLE SUMMARY: Wide fluctuations in abundance arising from variations in reproductive success are characteristic of many marine fish populations, including several pelagic fish species. The European anchovy is an economically and ecologically important resource, representing one of the most abundant species of the total Mediterranean fishery production. According to recommendations by the European Union, management plans should improve estimates of model parameters or biomass evaluation to provide a sustainable stock exploitation. The proportion of females spawning per day is one of the main parameters, including ichthyoplankton methods, for spawning biomass evaluation and is usually assessed by the postovulatory follicle (POF) method. Because of POF resorption rate is species-specific and influenced by residence temperature, the application of this method needs validation for species and area. This manuscript aimed to evaluate the resorption rate of postovulatory follicles in European anchovy in the central Mediterranean Sea, describing each degeneration stage based upon its histological features and estimating the duration of each POF stage in relation to water temperature experienced by the target species during the spawning peak. The provided results should allow for methodological advances in estimating the spawning biomass and in studying of reproductive output fluctuations, particularly for sustainable exploitation purposes. ABSTRACT: Accurate stock assessment estimates of fish resources are essential in fishery management. Wide fluctuations in abundance arising from variations in reproductive success are characteristic of many marine fish populations, including multiple spawner species. The proportion of females spawning per day is crucial in the application of egg production methods for spawning biomass evaluation and, usually, is assessed by postovulatory follicle (POF) method. Describing each degeneration stage of POF based upon its histological features allows for obtaining an aging key for ...

International audience ; Independence of science and best available science are fundamental pillars of the UN-FAO code of conduct 41 for responsible fisheries and are also applied to the European Union (EU) Common Fishery Policy (CFP), 42 with the overarching objective being the sustainable exploitation of the fisheries resources. CFP is 43 developed by DG MARE, the department of the European Commission responsible for EU policy on 44 maritime affairs and fisheries, which has the Scientific, Technical and Economic Committee for Fisheries 45 (STECF) as consultant body. In the Mediterranean and Black Sea, the General Fisheries Commission for the 46 Mediterranean (FAO-GFCM), with its own Scientific Advisory Committee on Fisheries (GFCM-SAC), plays a 47 critical role in fisheries governance, having the authority to adopt binding recommendations for fisheries 48 conservation and management. During the last years, advice on the status of the main stocks in the 49 Mediterranean and Black Sea has been provided both by GFCM-SAC and EU-STECF, often without a clear 50coordination and a lack of shared rules and practices. This has led in the past to: i) duplications of the 51 advice on the status of the stocks thus adding confusion in the management process and, ii) a continuous 52 managers' interference in the scientific process by DG MARE officials hindering its transparency and 53 independence. Thus, it is imperative that this stalemate is rapidly resolved and that the free role of science 54 in Mediterranean fisheries assessment and management is urgently restored to assure the sustainable 55 exploitation of Mediterranean marine resources in the future.

International audience ; Independence of science and best available science are fundamental pillars of the UN-FAO code of conduct 41 for responsible fisheries and are also applied to the European Union (EU) Common Fishery Policy (CFP), 42 with the overarching objective being the sustainable exploitation of the fisheries resources. CFP is 43 developed by DG MARE, the department of the European Commission responsible for EU policy on 44 maritime affairs and fisheries, which has the Scientific, Technical and Economic Committee for Fisheries 45 (STECF) as consultant body. In the Mediterranean and Black Sea, the General Fisheries Commission for the 46 Mediterranean (FAO-GFCM), with its own Scientific Advisory Committee on Fisheries (GFCM-SAC), plays a 47 critical role in fisheries governance, having the authority to adopt binding recommendations for fisheries 48 conservation and management. During the last years, advice on the status of the main stocks in the 49 Mediterranean and Black Sea has been provided both by GFCM-SAC and EU-STECF, often without a clear 50coordination and a lack of shared rules and practices. This has led in the past to: i) duplications of the 51 advice on the status of the stocks thus adding confusion in the management process and, ii) a continuous 52 managers' interference in the scientific process by DG MARE officials hindering its transparency and 53 independence. Thus, it is imperative that this stalemate is rapidly resolved and that the free role of science 54 in Mediterranean fisheries assessment and management is urgently restored to assure the sustainable 55 exploitation of Mediterranean marine resources in the future.

International audience ; Independence of science and best available science are fundamental pillars of the UN-FAO code of conduct 41 for responsible fisheries and are also applied to the European Union (EU) Common Fishery Policy (CFP), 42 with the overarching objective being the sustainable exploitation of the fisheries resources. CFP is 43 developed by DG MARE, the department of the European Commission responsible for EU policy on 44 maritime affairs and fisheries, which has the Scientific, Technical and Economic Committee for Fisheries 45 (STECF) as consultant body. In the Mediterranean and Black Sea, the General Fisheries Commission for the 46 Mediterranean (FAO-GFCM), with its own Scientific Advisory Committee on Fisheries (GFCM-SAC), plays a 47 critical role in fisheries governance, having the authority to adopt binding recommendations for fisheries 48 conservation and management. During the last years, advice on the status of the main stocks in the 49 Mediterranean and Black Sea has been provided both by GFCM-SAC and EU-STECF, often without a clear 50coordination and a lack of shared rules and practices. This has led in the past to: i) duplications of the 51 advice on the status of the stocks thus adding confusion in the management process and, ii) a continuous 52 managers' interference in the scientific process by DG MARE officials hindering its transparency and 53 independence. Thus, it is imperative that this stalemate is rapidly resolved and that the free role of science 54 in Mediterranean fisheries assessment and management is urgently restored to assure the sustainable 55 exploitation of Mediterranean marine resources in the future.

International audience Independence of science and best available science are fundamental pillars of the UN-FAO code of conduct 41 for responsible fisheries and are also applied to the European Union (EU) Common Fishery Policy (CFP), 42 with the overarching objective being the sustainable exploitation of the fisheries resources. CFP is 43 developed by DG MARE, the department of the European Commission responsible for EU policy on 44 maritime affairs and fisheries, which has the Scientific, Technical and Economic Committee for Fisheries 45 (STECF) as consultant body. In the Mediterranean and Black Sea, the General Fisheries Commission for the 46 Mediterranean (FAO-GFCM), with its own Scientific Advisory Committee on Fisheries (GFCM-SAC), plays a 47 critical role in fisheries governance, having the authority to adopt binding recommendations for fisheries 48 conservation and management. During the last years, advice on the status of the main stocks in the 49 Mediterranean and Black Sea has been provided both by GFCM-SAC and EU-STECF, often without a clear 50coordination and a lack of shared rules and practices. This has led in the past to: i) duplications of the 51 advice on the status of the stocks thus adding confusion in the management process and, ii) a continuous 52 managers' interference in the scientific process by DG MARE officials hindering its transparency and 53 independence. Thus, it is imperative that this stalemate is rapidly resolved and that the free role of science 54 in Mediterranean fisheries assessment and management is urgently restored to assure the sustainable 55 exploitation of Mediterranean marine resources in the future.