Abstract:
Laurencia venusta Yamada, originally described from the western Pacific Ocean, is recorded for the first time from the Atlantic Ocean. It occurs in Quintana Roo State, Mexico, which is located on the eastern portion of Yucatan Peninsula, Caribbean Sea. The present species belongs;to the subgenus Laurencia by-nature of possessing four pericentral cells per vegetative axial segment, secondary pit-connections between superficial cortical cells, and parallel-type arrangement of the tetrasporangia. The principal characteristics for species identification are: pale green color, soft and flaccid thalli, verticillate branching, and the presence of lenticular thickenings in the walls of medullary cells.