Fish of the Day – Lightfish

Our Fish of the Day was spat out of the mouth of a gemfish caught by one of our members from 400 metre deep water off the coast of Victoria.

Lightfish (of the family Phosicthyidae) are small, common, mid-water fishes of the deep sea. They are highly bioluminescent, meaning they glow-in-the-dark and have a row of lights (called photopores by scientists) along their belly. These lights have a faint blue glow that acts to cancel out their silhouette when viewed from below against the faint blue light of the sun filtering down through the water.  This counter-illumination acts as a form of stealth camouflage and makes it harder for predators to see them.

This species (tentatively identified as Phosichthys argenteus) has a large red light in front of its gills (see pics below) that is used to attract prey – primarily krill – to the vicinity of their ample mouth and needle sharp teeth.