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An Experimental Investigation of the Palatability of Kelp Bed Algae to the Sea Urchin Parechinus angulosus LESKE
Author(s) -
Anderson Robert J.,
Velimirov Branko
Publication year - 1982
Publication title -
marine ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.668
H-Index - 58
eISSN - 1439-0485
pISSN - 0173-9565
DOI - 10.1111/j.1439-0485.1982.tb00284.x
Subject(s) - algae , kelp , palatability , biology , sea urchin , thallus , botany , holdfast , kelp forest , brown algae , ecology , fishery , food science
. 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 2 S0 4 in the thallus. 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 2 S0 4 content, and it is non‐preferred. Our results therefore support our second hypothesis. Other implications of these results are discussed.