ABSTRACT: The mineralogical features of the substrate were generally considered a minor factor in structuring marine benthic communities. The aim of this work is to verify whether the presence of quartz minerals in rock may explicate differences, usually explained in terms of substrate roughness or other factors, in epibenthic communities. Laboratory tests on the hydroid Eudendrium glomeratum showed that its planulae settle preferentially on carbonatic, rather than quartzitic, substrates. To test the influence of quartz on established communities, we analysed the species composition and quantitative structure of sublittoral sessile assemblages on different rocks in several localities of the Ligurian and Tyrrhenian seas. The observed differences appeared to be related to the presence of quartz in the substrate rock. The interactions between organisms and minerals (bio-mineralogy) might play a significant role on benthic communities, affecting not only the initial colonisation, but also later assemblages. This potential role has been largely neglected to date and further studies are needed to prove its importance.

KEY WORDS: Substrate colonisation · Mineral composition · Marine benthos distribution · Hard substrates · Bio-mineralogy

Published in MEPS Vol. 193 (2000) on February 28
ISSN: 0171-8630. Copyright © Inter-Research, Oldendorf/Luhe, 2000