A new study reveals that the long-snouted seahorse can hunt successfully in different habitats, even if they are full of invasive algae, which reinforces the importance of underwater vegetation for the recovery of the species.
The seahorses of the Ria Formosa continue to surprise our researchers.
A new study conducted by Filipe Parreira, shows that the long-snouted seahorse (Hippocampus guttulatus) is a highly adaptable predator. Even in the face of the advance of the invasive algae Caulerpa prolifera, this species manages to maintain its feeding success — a discovery that brings hope for the survival and even recovery of its populations in the Ria Formosa.
“The sea horse is a curious fish — it is not a great swimmer, but it is a patient and efficient hunter. It uses the vegetation around it as camouflage and shelter, whether native or invasive,” explains Filipe Parreira.
The experiments, carried out in the Ramalhete Experimental Station, recreated three types of habitats typical of the Ria Formosa: seagrass, sediment and Caulerpa prolifera.
In each of these, the researchers tested three different factors that influence the predatory success of seahorses:
- Prey identity – to understand whether food choice depends on the type of habitat or the type of prey available;
- Prey availability – simulating scenarios of scarcity and abundance;
- Habitat complexity – to assess how vegetation density (more or less structured) affects hunting ability.
Hopeful results
Results show that increased vegetation density, both in seagrass and Caulerpa prolifera itself, doubles the success of seahorses in capturing prey.
This effect is due to the physical structure of the vegetation, which provides shelter and camouflage, allowing them to hunt stealthily and effectively.
In addition, seahorses proved to be highly adaptable:
- They can feed successfully in any of the habitats tested;
- They remain efficient even in situations of food scarcity;
- They become more selective when there is greater prey diversity, demonstrating flexible feeding behaviours.
“These results are very encouraging. They show that, despite rapid changes in the Ria Formosa, seahorses have a remarkable ability to adapt. However, healthy and dense seagrass beds remain essential for their success and recovery,” stresses the researcher.
A future reliant on underwater vegetation
The study emphasises that, although Caulerpa prolifera may temporarily offer refuge and structure, seagrass beds remain irreplaceable for the ecological balance of the Ria Formosa.
Their preservation and restoration are essential not only for seahorses, but for all other animals that inhabit this lagoon ecosystem.
References
The article “Predatory success of the long-snouted seahorse (Hippocampus guttulatus) across different habitats: implications for resilience under habitat change” was published in Marine Environmental Research.
📄 DOI: https://doi.org/10.1016/j.marenvres.2025.107247
🎥 Complementary videos of the experiments are available on the @Seaghorse YouTube channel,with a focus on “Experiências de eficiência alimentar”
