Carnivory in Acartia tonsa : a marine larviculture perspective

• Autor(a) principal: Aires, Pedro Nuno Leite Anjos
• Data de Publicação: 2015
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/14941
• topic: Biologia aquática; Artémia - Cultura (Biologia); Ácidos gordos

The nutritional component of copepods is one of the crucial factors for its good performance as live prey in marine larviculture. Carnivory is a crucial aspect of calanoid copepods diet, being its implications relevant for aquaculture. This study investigated i) the predatory behaviour between Acartia tonsa (Copepoda, Calanoida) and other live prey commonly used in marine larviculture (artemia and rotifers), taking into account the influence of temperature and microalgae availability, and ii) the diet supplementation of A. tonsa with artemia, in terms of eggs production, 48 h hatchability and fatty acid composition. The presence of A. tonsa significantly reduced artemia and rotifers survival. This predatory behaviour was shown to be dependent on copepod sex, being mainly associated with females. Predation decreased with decreasing temperature and with increasing availability of microalgae. The supplementation of A. tonsa diet with artemia did not promoted significant differences in egg production and 48 h hatchability. The fatty acid composition analysis revealed significant differences between eggs and copepods produced with the different diets tested, mainly due to C18:3 (n3) and C18:4 (n3). However, the percentages of HUFAs and DHA/EPA ratios were kept approximately constant. Overall, the supplementation of copepods with artemia does not improve its nutritional quality nor does it enhances egg production or quality.