Structure and Trophic Niches in Mobile Epifauna Assemblages Associated With Seaweeds and Habitats of Syngnathid Fishes in Cíes Archipelago (Atlantic Islands Marine National Park, North West Iberia)

Syngnathids are vulnerable fishes closely associated with seaweeds and seagrass, which provide shelter food resources. Even though most syngnathids commonly feed on small crustaceans, the feeding regimes may differ depending species prey availability. This is first monitoring study to explain syngnathid abundances dietary within macroalgal beds in Cíes Archipelago (Atlantic Islands Marine National Park, North West Iberian Peninsula). We sampled epifaunal assemblages seaweed communities dominated by canopy-forming macroalgae Gongolaria baccata Codium spp. seasonally during 2 years. The structure was mostly represented harpacticoid copepods, amphipods (especially gammarids) gastropods. Epifauna exhibited low plant-host specificity a higher dominance of more structurally complex G. baccata. specimens were assessed for trophic using stable isotopes (? 13 C ? 15 N). three ( Hippocampus guttulatus , Syngnathus acus Entelurus aequoreus ) inhabiting sympatric. They occupied highly similar positions (TPs), but differed niche size, such way that snake pipefish E. would likely smaller prey. assessment regime dominant great S. revealed contributed bulk diet, followed isopods, carideans, whereas mysidaceans not consumed. Seasonal changes both abundance confirmed seasonal residents Archipelago, migrating other areas autumn when cover drastically reduced modified. showed importance providing rich sources potentially contributing diversity syngnathids. Ongoing reduction certain regions (e.g., Mediterranean) should be considered potential ecological concern accompanying fauna, requiring further investigations.