Phenology of a deep-water population of Caulerpa racemosa var. cylindracea in the northwestern Mediterranean Sea

Abstract

Thalli of the invasive alga Caulerpa racemosa (Caulerpales, Chlorophyta) were measured monthly at 22 m depth off Villefranche-sur-Mer (southeastern France, Mediterranean Sea). C. racemosa was perennial at this site. Stolons (attaining up to 1 km/m2) comprised most of the thallus, with stolon biomass up to 12 times higher than the frond biomass. Biomass, stolon and frond lengths, and the number of fronds varied over the year, being lowest in winter. Compared to other species of Caulerpa in the Mediterranean Sea, C. racemosa showed lower total biomass and lower allocation to fronds relative to stolons.