Ceramium secundatum is a red alga which has an erect axis, numerous branches, marked by darker cortical bands at the boundaries of cell walls. The branches end in curved, paired apices (tips), and grows to 50-150 mm tall. Its native range extends from Iceland and Norway to Morocco, and through the Mediterranean to the Black Sea. It has been introduced to New Zealand and South Africa. Its only occurrence in North America has been an established population in Narragansett Bay, Rhode Island, and a drift specimen in Cape Cod Bay. Likely vectors are ballast water and fouling. This alga alga attaches to rocks, artificial structures, and other seaweeds, No impacts are known,