| Popis: |
Cassis tuberosa (L.) feeds on seaurchins at night, apparently detecting its prey by chemoreception. It generally bores one hole into the urchin test by cutting out a disc with its radula. The sutures of many tests appeared to have been chemically softened. All the internal tissue of the urchin except the gut contents are consumed. Afterwards varying proportions of the spines and tube feet are eaten. When C. tuberosa was presented with equal numbers of similarly sized Echinometra lucunter (L.) and Tripneustes ventricosus (Lamarck), significantly more E. Lucunter were eaten. Diadema antillarum (Phillipi) Eucidaris tribuloides (Lamarck), Meoma ventricosus (Lamarck) and Mellita quinquiesperforata (Leske) were not eaten. A type 2 functional response curve for Cassis tuberosa feeding on Echinometra lucunter was obtained by plotting changes in the number of prey eaten against changes in the number of prey offered. |
