This specimen is an elongated strand, 20 centimeters long, of Sargassum muticum, a brown seaweed, in which we have a main stem with small branches along its length. These branches have multiple fronds that can vary in size, that give this seaweed a bushy appearance. We can also observe some small round structures that are called aerocysts, which are little air-filled sacs that allow the seaweed to float.