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An Experimental Investigation of the Palatability of Kelp Bed Algae to the Sea Urchin Parechinus angulosus LESKE |
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| Authors: | Robert J Anderson Branko Velimirov |
| Institution: | Botany Department, University of Cape Town, Rondebosch 7700, South Africa;Institut für Zoologie der Universität Wien, Althanstr. 14, A-1090 Vienna, Austria. |
| Abstract: | Abstract. The relative palatability of 13 algae common in the kelp beds of the west coast of the Cape Peninsula, South Africa, is experimentally investigated with respect to feeding by the sea urchin Parechinus angulosus. We investigated 2 hypotheses: 1) that this important herbivore would feed selectively on these algae and 2) that Desmarestia firma, one of these algae, would be unattractive to Parechinus on account of the H Algal preferences are determined from 3 types of feeding experiment, results of which support our first hypothesis, and allow us to group the algae into 3 arbitrary categories: "preferred", "intermediate", and "non-preferred". To explain these patterns, we measured "relative astringen-cy" of each species (essentially a phenol measurement), and phenol content of 4 species (FOUN-DENIS method). Rates of feeding on single species are negatively correlated with relative astringen-cies (r = 0.76, P = 0.99). The high relative astringency of D. firma is caused by its high (18 % per dry mass) H |
| Keywords: | Kelp Desmarestia sea urchins palatability astringency phenol content feeding |