M. Zuschin et We. Piller, BIVALVE DISTRIBUTION ON CORAL CARPETS IN THE NORTHERN BAY-OF-SAFAGA (RED-SEA, EGYPT) AND ITS RELATION TO ENVIRONMENTAL PARAMETERS, Facies, 37, 1997, pp. 183-194
Bivalve assemblages on coral carpets in the Northern Bay of Safaga do
not form distinct associations, but gradually shift in faunal composit
ion. The taxonomic shift is accompanied by continuous variations in bi
valve density and percentage of living individuals as well as by a cha
nge of coral associations and potential bivalve habitats. The gradual
lateral change of associations is best documented by Tridacna maxima a
nd jewel box clams (Chamoidea) and is probably due to variations of th
e suspension load in the water column. High suspension loads in the wa
ter column are additionally indicated by 'giant oysters' (extremely la
rge individuals of Hyotissa hyotis) and striking agglomerates of Lopha
cristagalli. The vertical differentiation is best documented by the d
ecrease of the zooxanthellate Tridacna maxima and is probably due to t
he depth-dependent light penetration in the water column, which is att
enuated in areas of high suspension load.