Seahorses (Hippocampus spp.) are marine fish of high ecological and commercial value, but their aquaculture is often limited by high mortality rates during early developmental stages. Scaling up from experimental to commercial-scale production adds further challenges, particularly in maintaining consistent aquaculture conditions and survival across larger systems.
The present study was performed at CEPAM-ECOMARE (University of Aveiro, Portugal) and focuses on the optimization of the rearing protocols of Hippocampus erectus through improvements in water quality, feeding regimes, and tank management. The production system consists of a 10,000-L Recirculating Aquaculture System (RAS) operated in greenhouse facilities. Broodstock were maintained in 200-L tanks with controlled aeration and water flow to support feeding efficiency and biosecurity. Newborn seahorses were fed Artemia metanauplii enriched in DHA, gradually transitioning to frozen mysids as they matured.
Over a 7-month period, 18 hatching events from two breeding pairs resulted in 2,942 offspring. Eleven batches were reared up to 80 days post-hatching, with survival ranging from 63% to 98% and averaging 88%, far surpassing typical values reported in the literature (<30%). No consistent mortality patterns were observed, with long stable periods interrupted by occasional mortality events. The use of natural seawater, which did not lead to significant health issues, combined with regular cleaning and size-based sorting, contributed to tank stability and reduced stress.
The viability of H. erectus aquaculture was demonstrated by using relatively standard rearing tanks and procedures. The present protocol offers a promising basis for commercial-scale production and may serve as a model for rearing other seahorse species under controlled conditions.
This study was performed under project “BLUE BIOECONOMY PACT” (Project Nº. C644915664-00000026), co-funded by the Next Generation EU European Fund, under the incentive line “Agendas for Business Innovation” within Component 5—Capitalization and Business Innovation of the Portuguese Recovery and Resilience Plan (RRP), as well as project “PUFAPODS Merging blue and green food systems - Using marine gammarid amphipods supplied with plant food processing side streams to produce n-3 LC-PUFA” which is supported by FCT/MEC (https://doi.org/10.54499/LA/P/0094/2020).