Colonisation and growth strategies in two Codium species (Bryopsidales, Chlorophyta) with different thallus forms

Abstract

In clonal macroalgae, evidence of guerrilla and phalanx growth strategies has been related to a differential response due to a heterogeneous habitat. However, some species of the green algal genus Codium may exhibit different growth strategies at different times of their development. Since the crustose species C. bernabei and the erect C. fragile had different thallus forms as well as ecological and geographic distributions, we used them to test the idea that despite morphological and growth differences, both species exhibited a similar propagation strategy. We cultured, under controlled conditions, individuals of both species to determine, first, if isolated utricles can function as propagation units; second, the type of growth at different stages of development; and, third, if species show differences in specific growth rate. Our results indicated that isolated utricles could be used for propagation because they had the ability to regenerate young mat-forming thalli in both species.