The effect of live feeds bathed with the red seaweed Asparagopsis armata on the survival, growth and physiology status of Sparus aurata larvae.
Larval rearing is affected by a wide range of microorganisms that thrive in larviculture systems. Some seaweed species have metabolites capable of reducing the bacterial load. However, no studies have yet tested whether including seaweed metabolites on larval rearing systems has any effects on the larvae development. This work assessed the development of Sparus aurata larvae fed preys treated with an Asparagopsis armata product. Live prey, Brachionus spp. and Artemia sp., were immersed in a solution containing 0.5% of a commercial extract of A. armata (Ysaline 100, YSA) for 30 min, before being fed to seabream larvae (n = 4 each). In the control, the live feed was immersed in clear water. Larval parameters such as growth, survival, digestive capacity (structural-histology and functional-enzymatic activity), stress level (cortisol content), non-specific immune response (lysozyme activity), anti-bacterial activity (disc-diffusion assay) and microbiota quantification (fish larvae gut and rearing water) were monitored. Fish larvae digestive capacity, stress level and non-specific immune response were not affected by the use of YSA. The number of Vibrionaceae was significantly reduced both in water and larval gut when using YSA. Growth was enhanced for YSA treatment, but higher mortality was also observed, especially until 10 days after hatching (DAH). The mortality peak observed at 8 DAH for both treatments, but higher for YSA, indicates larval higher susceptibility at this development stage, suggesting that lower concentrations of YSA should be used until 10 DAH. The application of YSA after 10 DAH onwards promotes a safer rearing environment.
Portuguese Institute for the Ocean and Atmosphere (IPMA), Aquaculture Research Station (EPPO), Av. 5 de Outubro s/n, 8700-305, Olhão, Portugal.
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Castanho
Microbial Ecology and Evolution Research Group, Centre of Marine Sciences (CCMAR), Algarve University, Gambelas Campus, 8005-139, Faro, Portugal.|Institute for Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, Lessingstraat 8, D-07743, Jena, Germany.
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Califano
Portuguese Institute for the Ocean and Atmosphere (IPMA), Aquaculture Research Station (EPPO), Av. 5 de Outubro s/n, 8700-305, Olhão, Portugal.
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Soares
Microbial Ecology and Evolution Research Group, Centre of Marine Sciences (CCMAR), Algarve University, Gambelas Campus, 8005-139, Faro, Portugal.|IBB-Institute for Bioengineering and Biosciences, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, 1049-001, Lisbon, Portugal.
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Costa
MACRO-the Centre for Macroalgal Resources and Biotechnology and College of Science and Engineering, James Cook University, Townsville, QLD, 4811, Australia.
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Mata
Portuguese Institute for the Ocean and Atmosphere (IPMA), Aquaculture Research Station (EPPO), Av. 5 de Outubro s/n, 8700-305, Olhão, Portugal.
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Pousão-Ferreira
Portuguese Institute for the Ocean and Atmosphere (IPMA), Aquaculture Research Station (EPPO), Av. 5 de Outubro s/n, 8700-305, Olhão, Portugal. lribeiro@ipma.pt.
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Ribeiro
D000821:Animal Feed / Q000382:microbiology*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology; D001156:Artemia / Q000382:microbiology*; D001419:Bacteria / Q000187:drug effects; D004032:Diet / Q000662:veterinary; D004063:Digestion / Q000187:drug effects / Q000502:physiology; D005247:Feeding Behavior / Q000187:drug effects; D007814:Larva / Q000187:drug effects / Q000254:growth & development; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D000461:Rhodophyta / Q000737:chemistry*; D012403:Rotifera / Q000382:microbiology*; D021541:Sea Bream / Q000254:growth & development*
D000900:Anti-Bacterial Agents; D010936:Plant Extracts
Aquaculture; Cortisol; Digestive capacity; Growth; Lysozyme; Macroalgae; Microbiota; Seabream larvae