An unidentified green alga of the genus Anadyomene formed part of a persistent macroalgal bloom in Biscayne Bay, Florida since 2005. the bloom consisted of the native A. stellata and a smaller un-named perforate form. The thallus is sprawling and mesh-like, up to 5 cm long, and 3 cm wide. The thalli are mostly unattached. but do have elongated rhizoids. In a genetic analysis Anadyomene sp, appeared between A. saldanhae from South Africa and A. pavonina from Caribbean Panama. Anadyomene spp. were present in the Bay since the beginning of surveys in 1999, but increased sharply in 2004-2008. The Anadyomene bloom covered 60 km2 of seagrass habitat, with adverse affects on seagrasses, especially Turtlegrass, Thalassia testudinum. The Anadyomene bloom declined after 2014, leaving a fragmented cover of seagrasses which has not recovered.
Image Credit: Elisabeth Morcel via wikimedia commons and the CC BY-SA 4.0 license