The structuring role of microhabitat type in coral degradation zones: a case study with marine nematodes from Kenya and Zanzibar
Raes, M.; De Troch, M.; Ndaro, G.M.; Muthumbi, A.; Guilini, K.; Vanreusel, A. (2007). The structuring role of microhabitat type in coral degradation zones: a case study with marine nematodes from Kenya and Zanzibar. Coral Reefs 26(1): 113-126. dx.doi.org/10.1007/s00338-006-0184-8
Nematode genus assemblages were identified from four locations in coral degradation zones (CDZs) along the African east coast: Watamu and Tiwi Beach (Kenya) and Matemwe and Makunduchi (Zanzibar). Three microhabitat types were distinguished: coralline sediment, coral gravel and coral fragments. Nematode community composition was comparable to that of other studies dealing with the same habitat. The presence of a common genus pool in CDZs was reXected in the considerable similarities between samples. The addition of coral fragments as a habitat for nematodes resulted in an increased importance of taxa typical for coarse sediments and large substrata. Local and regional turnover were of the same order of magnitude. The structuring effect of microhabitat type clearly overrode the eVect on a local and regional scale. Differences in sediment characteristics were more important in structuring the nematode assemblages than diVerences between the coralline sediment and coral fragments. No effect related to the three-dimensional structure of coral fragments was found. Differences between nematode assemblages in the coralline sediment and on coral fragments were attributed to the exposed nature of the latter habitat, its large surface area and its microbial or algal cover. Differences in available food sources were refected in nematode trophic composition.