Tonight, even in the deep, there is light. Glowing ammonites rise from the abyss. Ammonites are mollusks, related to octopus and squid. These scaphitids are no bigger than a human hand. For weeks, they’ve been gathering in the coastal depths. In the deep, these lights may help lure planktonous food, but tonight they serve a different purpose. They’ve been drawn to the surface to mate, and soon there are thousands in each school. Neighbor triggers neighbor, creating waves of bioluminescence. They have complex nervous systems, controlling light-producing cells called photocytes. The males jostle for a place around the larger females. Clues from their displays tell her who’s fittest and who is the best mate. As couples entwine, they coordinate their light displays. If he can’t match her precise rhythm, he’ll be rejected. But there is perfect synchrony. This pair will now spawn and help produce the next generation. After fertilization, the females enter the shallows to release their eggs. As with most cephalopods, breeding is the final act of their short lives. By morning, these lights will have flickered and died. This magical night will be their last.
