“…The latter are released in concert (Drew and Abel, 1988) in species-specific short intervals (Clifton, 1997;Clifton and Clifton, 1999 Ballantine, 1982;Dong and Tseng, 1980;Drew, 1993Drew, , 1995Hillis-Colinvaux, 1980;Noble, 1986). They abound in a range of reef habitats (Gilmartin, 1960;Hillis-Colinvaux, 1980Roberts et al, 1987;Taylor, 1950Taylor, , 1960Tsuda and Kamura, 1991;Tsuda and Wray, 1977;Van den Hoek et al, 1978). Several morphological traits seem to be linked to particular habitats, e.g., unconsolidated substrata or wave exposed sites (Hillis-Colinvaux, 1980); these traits must have been acquired once or more depending on whether adaptation to these environments occurred once or multiple times.…”