During experiments on the giant axons of the Longfin Inshore Squid (loligo pealei) at the Marine Biological Laboratory in Woods Hole, MA; we were fascinated by the fast color-changing nature of the squid’s skin. Squids (like many other cephalopods) can quickly control pigmented cells called chromatophores to reflect light. The Longfin Inshore has 3 different chromatophore colors: Brown, Red, and Yellow. Each chromatophore has tiny muscles along the circumference of the cell that can contract to reveal the pigment underneath.
We tested our cockroach leg stimulus protocol on the squid’s chromatophores. We used a suction electrode to attach to the squid’s fin nerve, then connected the electrode to an iPod nano as our stimulator. The results were both interesting and beautiful. The video below is a view through an 8x microscope zoomed in on the dorsal side of the fin.