And gels made from them, as well as skin lotions, massage creams promoting weight loss, and facemasks, have long been trendy products in the industry. Worldwide, there are over 23,000 known species of seaweed. They come in vastly different shapes and sizes. Chlamydomonas measure from five to 25 millimeters, whereas kombu grow to several hundred meters.
目前全世界已知的海藻種類約有 2 萬 3 千多種，大小形狀差異甚大，有長度僅 5 到 25 厘米的單胞藻，也有長達數百公尺的昆布；形狀則或成群體、管狀，也有絲狀、薄膜狀等。