Effect of increasing docosahexaenoic acid content in weaning diets on survival,growth and skeletal anomalies of longfin yellowtail (Seriola rivoliana,Valenciennes 1833) |
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| Authors: | Antonio Mesa‐Rodriguez Carmen Maria Hernández‐Cruz Mónica Beatriz Betancor Hipólito Fernández‐Palacios Marisol S Izquierdo Javier Roo |
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| Institution: | 1. Grupo de Investigación en Acuicultura, Parque Científico Tecnológico Marino, Universidad de Las Palmas de Gran Canaria, Telde, Canary Islands, Spain;2. Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, UK |
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| Abstract: | Five isoproteic (54.8%) and isolipidic (24.1%) microdiets, which varied in their docosahexaenoic acid (DHA) content (0.25%, 0.75%, 1.64%, 1.99% and 3.17%; dw), were manufactured to determine its effects on longfin yellowtail Seriola rivoliana larvae in terms of fish biological performance, whole body fatty acid profile and incidence of skeletal anomalies from 30 dah (11.31 ± 1.79 Total Length, TL) to 50 dah (19.80 ± 0.58 mm TL). The inclusion of dietary DHA up to 3.17% (dw) improved larval resistance to air exposure, although DHA did not significantly affect fish final growth or final survival. Indeed, high levels of dietary DHA (1.99% and 3.17%, dw) tended to increase the incidence of skeletal anomalies in S. rivoliana larvae, albeit no significant differences were observed. Furthermore, the occurrence of severe anomalies such as kyphosis and lordosis, was mainly associated to the larvae fed the highest levels of dietary DHA. In terms of survival, increasing dietary DHA levels did not significantly affect longfin yellowtail survival rate, despite a tendency for enhanced survival. The results of the present study proved that the inclusion of dietary DHA in inert diets up to a 3.17% (dw) and a DHA/EPA ratio above 3.1 increased the final survival and stress resistance in S. rivoliana larvae. |
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| Keywords: | docosahexaenoic acid fish larvae longfin yellowtail microdiets skeletal anomalies |
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