European eel larval quality and feeding regime: Establishing first-feeding culture
Development of closed-cycle hatchery technology is pivotal for sustainable aquaculture production of the European eel ( Anguilla anguilla ). In this context, the research conducted within this PhD project contributes to generating the knowledge needed to establish larval culture of European eel by a...
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| Format: | Book |
| Language: | English |
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DTU Aqua
2022
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| Online Access: | https://orbit.dtu.dk/en/publications/7fbc90b0-4023-45dd-baf2-4092b38dce96 https://backend.orbit.dtu.dk/ws/files/282254159/Elisa_Benini_PhD_thesis.pdf https://backend.orbit.dtu.dk/ws/files/282254161/Correction_sheet.docx |
| Summary: | Development of closed-cycle hatchery technology is pivotal for sustainable aquaculture production of the European eel ( Anguilla anguilla ). In this context, the research conducted within this PhD project contributes to generating the knowledge needed to establish larval culture of European eel by addressing biochemical, nutritional and developmental factors influencing early larval stages. This involves experimental studies, which use an integrative set of tools to elucidate relations between offspring survival, developmental indicators and molecular mechanisms in the pursuit of insights into the early life history of the enigmatic eel larvae. The thesis frames the outcomes of four studies within three main topics: i) larval quality and biochemical composition, ii) maturation of the gut during the transition between endogenous and exogenous feeding and iii) first-feeding diets and dietary regimes for eel larval culture. All those aspects influence larval development and survival thereby being vital for advancing the establishment of feeding larval culture of European eel. In aquaculture, variable egg quality from captive broodstock is a common problem affecting viable offspring production. A stable supply of high quality eggs requires comprehensive understanding of the factors that regulate gamete and offspring quality. For the European eel, reproductive protocols involve administration of pituitary extracts from carp (CPE) or salmon (SPE) to induce and sustain oocyte development and vitellogenesis. During vitellogenesis that lasts several months, yolk constituents (for example protein, lipid, and amino acid) are incorporated into the oocytes. In this regard, Study 1 compared the effects of CPE and SPE on the biochemical composition of eggs and yolk sac larvae as well as the subsequent nutrient utilization by the developing larvae during the yolk-sac stage. The results showed that the type of pituitary extract used to induce vitellogenesis in female eel influenced the biochemical composition of the offspring, ... |
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