Where should I settle? An investigation into the larval settlement patterns of Mesocentrotus franciscanus

Abstract

The red sea urchin, Mesocentrotus franciscanus, is an ecologically and economically important species. Although there has been extensive work on the life of the adults, little work has been done on the larval stage of its life history, namely the settlement cues of competent larvae. This study tested 6 treatments, with 24 hour exposure, to test which factor induced the most efficient larval settlement. At the conclusion of this study, Calliarthron tuberculosum, showed significantly higher settlement results for larvae, with an average of 12 ± 0.632 out of 15. Biofilms from purple urchins and urchin free environments also seemed to have an effect on settlement, but this was not as significant of a difference as the coralline algae. Red urchin biofilm, kelp detritus, and sea water did not have a significant effect on the settlement of the larvae.