Alternate Title

Habitat Selection Among Fishes and Shrimp in the Pelagic Sargassum Community: The Role of Habitat Architecture


The pelagic Sargassum community represents an excellent model system to advance our understanding of how a complex habitat can influence biotic interactions. This study examined the habitat architecture of pelagic Sargassum fluitans to determine its effects on habitat selection for one shrimp species (Leander tenuicornis) and two fish species (Stephanolepis hispidus and Histrio histrio). Specifically, we manipulated interthallus spacing and depth of Sargassum habitats independently (i.e., in separate experimental trials) to test whether spatial components of habitat architecture influence habitat selection by these animal inhabitants. Additionally, two differing habitats (Sargassum vs intermingled seagrass species, Thalassia testudinum and Syringodium filiforme) were tested to determine whether structural components of habitat architecture influenced habitat selection. Results showed no significant effect of habitat selections for interthallus spacing experiments for L. tenuicornis and S. hispidus. However, H. histrio selected habitats with medium interthallus spacing characteristics in two experiments. All three animals selected habitats with a greater depth aspect. Finally, L. tenuicornis and H. histrio selected habitats with greater structural complexity (i.e., Sargassum habitat). These results demonstrate that habitat architecture (i.e., spatial and structural components) of Sargassum influences habitat selection by the aforementioned fauna and further illustrate that this pelagic macroalga is an essential habitat for multiple species.