COLONY ARCHITECTURE OF MILLEPORA-DICHOTOMA FORSKAL

In the Gulf of flat, the hydrozoan coral, Millepora dichotoma Forskal exhibits four main morphotypes: encrusting, delicate lace-like, leaf-l ike bladed and robust ''box-work''. The distribution of these morphoty pes was found to vary with depth and between locations. The encrusting form was found in all sites and appeared to be the initial growth for m adopted by M. dichotoma. The distribution of the other three growth forms suggested that further development from the encrusting form depe nds upon environmental conditions. The encrusting form was found at al l sites but was dominant in highly energetic environments. The lace-li ke form develops from the encrusting form in low energy environments. In somewhat higher energy environments, repeated damage to the lace-li ke form moves development towards the bladed growth form and the box-w ork growth form. A model of this development is presented in which cri tical factors controlling the development of the different growth form s are sediment levels and damage to colonies. Both of these factors ar e linked with levels of turbulence in particular environments. (C) 199 8 Elsevier Science B.V.