Improvements in the production technology of red porgy (Pagrus pagrus) larvae and fry: importance of rearing conditions and diet nutritional value on their quality
The main objective of this study was “to improve the production technology of red porgy (Pagrus pagrus) larvae and fry”. Specific objectives were divided in two complementary and consecutive phases; the first part was mainly based on a biological approach where specific aspects of the first developm...
| Autores: | , |
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| Tipo de recurso: | tesis doctoral |
| Fecha de publicación: | 2009 |
| País: | España |
| Repositorio: | accedaCRIS portal de investigación de la Universidad de las Palmas de Gran Canaria |
| OAI Identifier: | oai:accedacris.ulpgc.es:10553/4599 |
| Acceso en línea: | http://hdl.handle.net/10553/4599 |
| Access Level: | acceso abierto |
| Palabra clave: | 310502 Piscicultura Bocinegro (Peces) |
| Sumario: | The main objective of this study was “to improve the production technology of red porgy (Pagrus pagrus) larvae and fry”. Specific objectives were divided in two complementary and consecutive phases; the first part was mainly based on a biological approach where specific aspects of the first development stages of this species were described. Followed by a second part where this knowledge was applied to develop a standard larval rearing protocol for commercial production of this species. In this sense, it was determined that red porgy larvae are visual feeders and hatch with an incomplete and nonfunctional visual and digestive system. Along the third and fourth days posthatch, major structural changes took place in the visual and digestive systems, with the definition and pigmentation of the primary photoreceptors (cones) and mouth opening. At this moment, the first digestive activity was detected in the midgut, which enables the larva to begin its exogenous feeding. The second most important change in relation to visual system development was detected around 20dah, when second photoreceptors nuclei appeared (rods), these structures prepared larvae with a greater sensitivity and visual acuity, allowing them to prey under restricted light conditions. These changes, agreed with the detection of the first gastric cells and the progressive migration of the larvae, from shallow to depth water, suggesting changes in feeding habits and culture conditions at this stage. |
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