Incipit vita nova is the motto of my alma mater, Scripps College, which means “here begins new life.” During my recent field trip to document the reproductive behavior and characteristics of the big fin reef squid, this ran through my head underwater as we watched mating pairs, quite literally, begin new life, as they mated and laid their eggs.
Squid, like other cephalopods, use displays of patterns with varying levels of contrast to communicate through their skin. Through the use of chromatophore cells, which the squids can actively control the size of. These cells change sizes to hide or expose layers of pigment cells called iridiophores and leucophores in the skin. Different patterns and their intensity signal different levels of attraction and aggression for example. We got some terrific close-up footage of the chromatophores opening and closing as the squid changed colors swimming past us.
After combing through some of the footage that we shot over 5 days in the Lembeh Strait, we were able to see the full sequence of reproductive behavior from advertising for a mate and male-male competition to the formation of a mating pair following by mating and subsequent egg laying. What was the most thrilling moment was when I was above the two spawning pairs in about 5 ft of water, filming their activities when one of the males that had been courting the female suddenly swooped down. He inserted his hectocotylus (a specialized arm for delivering packets of sperm) into her mantle to deposit his sperm! The female will then use these to fertilize the eggs just before she lays them.