Cryptopleura ruprechtiana is a bright to deep red alga with an iridescent purplish or brownish shine. The thallus is flattened and erect and divided into many fan-shaped blades. The edges are covered with small ruffles and serves as the most distinguishing feature of this alga. This specimen was about 25 cm long (can reach 40 cm). The holdfast was still intact.
Found washed ashore on the beach at the Dungeness National Wildlife Refuge. Cryptopleura ruprechtiana lives on rocks in the low intertidal and subtidal down to 30 m. It seems to grow well in areas of moderate to heavy surf, but is considered an obligate understory alga. This means that in order to thrive in these rough waters it requires some protection from the surf and light by either a canopy layer or some other physical barrier, especially in the intertidal.
Cryptopleura ruprechtiana also provides substrate and habitat. Sometimes it grows as an epiphyte, which is a plant that grows on top of another plant, but is also a host to many epiphytes including crustose corallines and the parasitic alga Gonimophyllum skottsbergii. Animals also find their home on and in the holdfast.