BODY-SIZE DISTRIBUTION IN A MARINE METAZOAN COMMUNITY AND THE FRACTALDIMENSIONS OF MACROALGAE

Habitat architecture has two major components, size and structural var iety. Both these attributes are incorporated in measurements of fracta l dimensions which are essentially an expression of habitat size in re lation to the scale of measurement. Therefore, the fractal dimensions of a habitat, coupled with energy requirements, may be one explanation for the species abundance/body size distribution of the associated an imal assemblages. This concept is tested in the marine environment by an analysis of the fractal dimensions and epifaunal assemblages of fou r species of macroalgae on the Isles of Scilly. It is shown that the s lope of the regression of animal abundance against body size (estimate d by sieve mesh size) is related to the fractal dimension of each weed . The application of the energetic equivalence rule, however, overesti mates the abundance of smaller animals. In general, smaller animals ap pear to use proportionately less of the community resources. It is sug gested that this is a result of unequal availability of resources due to the different feeding and resource partitioning traits between macr ofauna and meiofauna.