Annulated sea snake, Hydrophis cyanocinctus, venom was investigated using reversed-phase high-performance
liquid chromatography coupled to electrospray mass spectrometry (ESI-MS) and matrix-assisted laser desorption/
ionization time-of-flight mass spectrometry (MALDI-TOF/TOF). MALDI-TOF/TOF identified three compounds (a
short-chain neurotoxin, a long-chain neurotoxin and a basic phospholipase A2); whose molecular weights were estimated
to be 7285, 10838, and 14235 Da, respectively. Moreover, evolutionary relationship of each protein (identity more than
70%) was separately investigated via phylogenetic trees. This study was done as complementary investigation on the
composition of the venom of H. cyanocinctus, the annulated sea snake from the Persian Gulf.