Frontiers in Marine Science (Jun 2014)
Macrofauna associated with <i>Saccorhiza polyschides</i> (Lightfoot) Batters 1902 holdfasts
Abstract
Distribution patterns of species and the causes driving its distribution have always been central questions in ecology, as well as the mechanisms determining species composition and structure of biological assemblages. In the present work the distribution patterns of the macrofauna associated with Saccorhiza polyschides holdfasts along the western coast of Iberian Peninsula was studied. The aims of this work were to evaluate (i) the role of Saccorhiza polyschides holdfasts as suitable habitat for littoral macrofauna, (ii) the influence of latitude on the colonization patterns, and (iii) to examine the processes determining these colonization patterns. This study took place at three different locations along the western coast of Iberian Peninsula, Ferrol (Galicia, northern Spain), Viana do Castelo (northern Portugal) and Figueira da Foz (central Portugal). Sampling of macrofaunal organisms was held by scuba diving and eight samples were collected on the nearshore rocky subtidal zone of each site. All species were identified to the highest taxonomic level possible. Similarity analyses (Cluster and NMDS) showed the separation of the sampling sites in two different groups: one corresponding to the northern limits of the study area (Ferrol) and another corresponding to the two Portuguese sampling sites (Viana do Castelo and Figueira da Foz). The results showed that Saccorhiza polyschides provides a suitable habitat for 107 species, mainly small crustaceans like amphipods and molluscs. The inner species partitioning of samples suggests the additional influence of the exposure degree of each sampling area. The observed colonization patterns are consistent with habitats with high level of environmental stress, which could be related to the seasonal instability of holdfasts.
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