Stressful Conditions Give Rise to a Novel and Cryptic Filamentous Form of Caulerpa cylindracea

Morphological plasticity can enable algae to adapt environmental change and increase their invasibility when introduced into new habitats. Nevertheless, there is still a lack of knowledge on how such affect the invasion process an invasive species. In this context, high in genus Caulerpa well documented. However, after extremely hot summer, previously unreported filamentous morphology cylindracea was detected; indeed, could only be confirmed taxonomically in-depth morphological characterization molecular analysis with genetic marker tuf A. We describe ex situ culture experiment which showed that stressful conditions, as temperatures, trigger change. Almost all thalli maintained at constant extreme temperature 29°C died, but being returned optimum began develop from surviving microscopic tissue. contrast, control 21°C regular throughout experiment. When C. develops morphology, it may act cryptic invader because difficult detect field. Furthermore, filaments likely improve ’s capabilities regard resistance, persistence dispersion have important role re-colonization process, population disappears following period conditions. Possibly, ability respond plastically conditions might explain its remarkable success