Green Sea Pansy, Udotea flabellum, also known as the Mermaid’s Fan Plant is a somewhat common algae found throughout the Caribbean and Western tropical Atlantic. They are found primarily in shallow waters, but can occasionally be found as deep as 50′ or more. They will thrive in your reef tank or refugium and may go through die off and regrowth cycles. Each growth cycle can last for several months, and after they die off, the holdfast will send out a new shoot that will become a new “fan”. The “fan” is calcareous and is dark green. They require calcium to grow and to really strive in your tank. We normally collect them between 3 to 4 inches.