ECOLOGY AND TAXONOMY OF Halimeda 



215 



Fig. 71. Early stages in the clonal de\cl()i)iiieiit in H. inonile bj- disintegration of older 

 thallus, and eventual development of new holdfasts near the bases of actively 

 growing branches. In this way several vegetative thalli are produced. Two of the 

 actively growing erect branches have whitish to pale green apical segments which 

 are less than 48 hours old. Scale bar is 1 cm. 



parental filament is epii3hyte-free. Cloning in Halimeda serves as a 

 defence against epiphytes even as it increases the numbers of the plants. 



C. Reproduction in other Caulerpales 



The genera Penicillus, Ehipocephalus and Udotea also produce new 

 thalli by filamentous runners from holdfast filaments (Colin vaux et al, 

 1965; Colinvaux, 1968b, c; Hilhs -Colin vaux, 1973, includes earlier 

 literature). In aquaria the filamentous connections have been of a single 

 filament or several to many intertwined filaments. The connections 

 observed have been considerably more delicate than the rhizome-like 

 connections illustrated by Duchassaing (1850) for Penicillus ( =Nesea), 

 and by Ernst (1904) for Udotea, and they do not appear to persist. New 



