SUBSTRATE PARTICLE SIZE AND THE OCCURRENCE OF LOVENIA ELONGATA (ECHINODERMATA: ECHINOIDEA) AT TABA, GULF OF ELAT (RED SEA)

ABSTRACT

The population density of the spatangoid Lovenia elongata (Gray) was ascertained in three adjacent zones with substrates of different particle sizes. Lovenia was most numerous in the substrate with a mean particle size (M) of 280 μ and a sorting coefficient (S_o) of 1.4. The gut contents of animals in this substrate indicated selective feeding (M = 390μ S_o 1.3). A summary of characterizations of the substrate of other burrowing echinoids is given.