Spatiotemporal patterns of phenology of the alien Phaeophyceae Sargassum muticum on the Atlantic coast of Morocco

The present study focused on the dynamics of phenology and life cycle Phaeophyceae invader Sargassum muticum at three sites Atlantic coast Morocco over a period two years (2013 2014). results showed that S. has distinct growth phases; one with slower in winter followed by faster spring-early summer, when species exhibited high elongation branching activities thalli length ranging from 1 to more than 5 m depending site. site S1, rocky substratum covered submerged sands, promotes elongation, maximum lengths 643.33 11.10 cm recorded July. At (S2 S3), seaweed depends pools’ depth. Although is enhanced water body depth, settlements’ density (5-48 ind. m–2) seems be mainly related nature substrate. maturity index progressively increases spring early it reaches highest values. abundant easily acclimated shallow rockpools (sufficiently lighted semi-exposed wave action mid lower tidal levels) protected sandy bottom low hydrodynamic forces.