Popis: |
American lobsters (Homarus americanus) were presented with various numerical combinations of sea urchins (Strongyhcentrotus droebachiensis) and rock crabs (Cancer irroratus) in long-term laboratory feeding experiments. They exhibited a 5:1 preference for crabs when the numerical ratio of urchins to crabs varied from 0.25:1 to 8:1. Lobsters presented with a superabundance of sea urchins (urchin:crab ratios of 16:1 and 100:1) maintained relatively constant proportions of urchins and crabs in their diet. Direct observation indicated that lobsters feed selectively. Their role as key predators in kelp–sea urchin communities is discussed. Key words: food preference, predation, Canadian Atlantic, bioenergetics |