Currently, a broad diversity of fluorescent proteins among marine organisms range from cyano-red emissions. Fluorescent proteins differ in their DNA sequences from green fluorescent protein (GFP). We identified cDNA encoding the gene of a new protein from the reef coral Hydnophora rigida of the Merulinidae family. Both the spectral properties and putative primary sequence of the protein has been determined. The cloned cDNA encode peptide we call HriCFP is comprised of 134 amino acids. It has characteristics of a cyano fluorescent protein (HriCFP) and its sequence is markedly different from known GFP from the hydroid jellyfish Aequorea victoria. HriCFP was cloned, expressed, purified and exist as monomer. The peptide mass finger print on the purified protein confirmed identity of HriCFP. (C) 2010 Elsevier Inc. All rights reserved.