SELFDOTT REPORT 2010-2011
In reproduction, genotyping of a large number of broodstock throughout the Mediterranean indicated that although the samples were not in Hardy-Weinberg equilibrium, there was no signal of a single population structure. In the broodstocks maintained in Spain we obtained spontaneous (without the use o...
| Autores: | , |
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| Tipo de recurso: | otro |
| Fecha de publicación: | 2013 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/313587 |
| Acceso en línea: | http://hdl.handle.net/10261/313587 |
| Access Level: | acceso abierto |
| Palabra clave: | Centro Oceanográfico de Murcia Bluefin tuna Acuicultura Thunnus thynnus Atún rojo Domestication Domesticación Culture Cultivo Reproduction Reproducción Scombridae |
| Sumario: | In reproduction, genotyping of a large number of broodstock throughout the Mediterranean indicated that although the samples were not in Hardy-Weinberg equilibrium, there was no signal of a single population structure. In the broodstocks maintained in Spain we obtained spontaneous (without the use of any hormonal treatments), long-term and high fecundity and fertility spawning in both years, whereas in Malta fish spawned successfully after GnRHa treatment. Parentage contribution analysis demonstrated that 15 individuals were engaged in the majority of the crosses (460 out of 530 crosses) of the 2009 spawning season, with the remaining 10 fish being responsible for 13% of the crosses. It is important to note that both GnRHa implanted and control broodstocks participated in spawning. The study of puberty in captive BFT indicated that reproductive maturation begins after the 3rd year in males and the 4th in females, but rearing conditions may result in further delays. It was also shown that sexual dimorphic differences may exist in the regulation of puberty in this species. In the study of broodstock nutrition, the experimental diet resulted in a superior growth, higher GSI values and a more advanced gonadal development, and lower occurrence of apoptosis of vitellogenic oocytes. A method was developed for the monitoring of fish size and behavior in captivity. The closing of the life-cycle of bonito (Sarda sarda) in captivity was achieved. In 2010 and 2011, encouraging survival and growth results allow us to assume that BFT domestication should be feasible in a next future. But, larval rearing is still at the research stage and has not reached the status of a commercial level. Mesocosm and pseudo-green methodologies implemented in large tanks have been substantially improved as it is evident from the survival of the best rearing trials (2.5 -3 % at 25DPH). The knowledge base in larval and fingerlings rearing have been substantially documented both at the academic and at the rearing levels and gave us clear indications for improving rearing techniques and biological performances. The logistics of the eggs transport should be further considered (temperature management) to guarantee the smooth transfer of eggs. Currents, luminosity parameters and feed quality which have a significant effect on vision, feed intake, growth and survival as soon as the early stages have to be fine tune. It is still impossible to sustain an acceptable growth and survival without YSL post 17DPH whatever the rearing methods. So, even if weaning of juveniles (post 25DPH) on artificial diet was achieved, the later have to be improved and lead to better results. An alternative feed source as copepods could significantly contribute to enhance the early performances of the larvae while it seems that an early weaning window could lead to feeding sequence simplification. Artificial rearing methods (pseudo green and clear water) implemented in small tanks although improved still does not performed as mesocosm or pseudo-green ones in large tanks and have to be further improved to meet the needs of an experimental comprehensive/comparative approach. 376 YOTYs have been captured from the wild. 233 living fish have been placed in two floating cages for the feeding trials. A technique for transporting from the wild and from the cages, to the land based facilities has been successfully developed. The stomach contents analysis of wild dead fish shown that juveniles are opportunistic and generalist feeders. The tuna feed formulation must include appropriate ingredients in order to achieve higher dietary amino acid and protein concentrations, lower total lipid content, higher dietary n-3 concentrations and higher vitamin C and E concentrations. A dry food has been developed and tested in wild and full reared juveniles. Dissemination activities were carried out including specialized sessions at the EAS meeting in Rhodes and a stakeholder workshop in Madrid. |
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