The effect of Patella vulgata pedal mucus on the settlement and development or propagation of Skeletonema costatum and Fucus spiralis

Investigation was made into the potential effect of Patella vulgata pedal mucus on the settlement and development (propagation) of the microalga Skeletonema costatum and propagules of the macroalga Fucus spiralis. Pedal mucus increased the settlement of S. costatum and F. spiralis by factors of 70 and 13, respectively. Following settlement, propagules of F. spiralis entrapped in pedal mucus developed at a reduced rate compared with those on a control surface, probably arising from intraspecific competition. No effect of pedal mucus on the propagation of S. costatum was observable. It is concluded that, although pedal mucus can increase the settlement of algae, this has little overall advantage for those species entrapped and therefore may only serve to increase localized resources for grazing P. vulgata.