C. merolae is a club-shaped, unicellular red algae that lives in highly acidic environments and in warm conditions. Merolae has a single chloroplast and a single mitochondrion, but lacks a vacuole and a cell wall. The organism's genome was the first full algal genome to be sequenced in 2004. Its plastid was sequenced in 2000, 2003 and its mitochondrion in 1998.