Comparison of epifaunal assemblages between Cymodocea nodosa and Caulerpa prolifera meadows in Gran Canaria (eastern Atlantic)

Abstract

Epifaunal invertebrates are sensitive to changes in the identity of the dominant host plant, so assessing differences in the diversity, abundance and structure of epifaunal assemblages is particularly pertinent in areas where seagrasses have been replaced by alternative vegetation (e.g. green seaweeds). In this study, we aimed to compare the diversity, abundance and structure of epifaunal assemblages, with particular emphasis on amphipods, between meadows dominated by Cymodocea nodosa and the green algae Caulerpa prolifera on shallow soft bottoms of Gran Canaria Island, determining whether patterns were temporally consistent. The epifaunal assemblage structure (abundance and composition) consistently differed between both plants, being more diverse and abundant epifaunal assemblages associated with C. prolifera-dominated beds than those inhabiting C. nodosa meadows. Amphipods constituted ca. 70% of crustaceans for the overall study, including 37 species belonging to 16 families. The amphipods abundance recorded was ca. 3 times larger in C. prolifera-dominated beds (1248.13 ± 136.83 ind. m-2, mean ± SE) than in C. nodosa meadows (396.88 ± 77.36 ind. m-2). Multivariate analysis of the community showed significant differences between habitats, with a clear segregation of the species. For instance, Microdeutopus stationis, Dexamine spinosa, Aora spinicornis, Ischyrocerus inexpectatus and Apherusa bispinosa were more abundant in C. prolifera-dominated beds; while the new genus, new species of caprellid, Mantacaprella macaronensis, dominated in C. nodosa meadows. However, some species such as Pseudoprotella phasma and Ampithoe ramondi were found without significant differences in both habitats.