Pyrosome

Pyrosomes are free-floating colonial tunicates often found in tropical waters. Pyrosoma atlanticum is one of the few pyrosomes that inhabits the temperate west coast of North America. The colony forms a tube, which may reach a length of 60 cm and may be colorless, pink, grayish or blue-green. Pyrosomes are brightly bioluminescent, producing an intense blue-green glow when disturbed. MBARI’s remotly operated vehicles (ROVs) have observed pyrosomes from surface waters down to 900 meters depth.