Distribution and trophic structure of annelid assemblages in a Caulerpa prolifera bed from southern Spain

Abstract

The main subject of this study was to evaluate the effects of the temporal variation of the Caulerpa prolifera cover on the composition and trophic structure of the annelid assemblage in a meadow from Southern Spain. A total of 51 species of polychaetes and 1 oligochaete were identified, of which only 6 species represented more than 80% of the total dominance (the oligochaete Aktedrilus cf. monospermathecus, the capitellids Notomastus latericeus and Capitella capitata, the syllid Exogone verugera, the nereidid Neanthes caudata and the cirratulid Aphelochaeta filiformis). The annelid assemblage was similar to others found in seagrass systems from nearby geographic areas. As opposed to other taxonomic group such as molluscs and crustaceans, annelid distribution was more influenced throughout the meadow by the percentage of organic matter in sediment than by algal cover. With respect to trophic structure, the meadow was dominated quantitatively by surface and subsurface deposit feeders; surface deposit feeders and carnivores showed the more homogeneous distribution throughout sampling periods and stations; omnivores were abundant in high cover and high organic matter content stations, meanwhile subsurface deposit feeders were abundant in the rest of the meadow.