>Anna sights a lone cuttlefish weaving its way through a gorgonian thicket that skirts an ancient lava flow on the southern shore of Alor, in Indonesia. The animal blends so masterfully with its backdrop that if it weren't for its movement, Anna would have missed it altogether. Like their close relatives octopus and squid, cuttlefish are famous for brainpower as well as their talent for intra-species communications and altering color patterns for camouflage (as a group, cephalopods exhibit the most diverse repertoires of chromatic displays nature has to offer). This remarkable adaptation is driven by a visual analysis of surroundings. The information is transferred via nerve impulses to overlapping layers of muscle-lined, pigmented skin organs, known as chromatophores. When stimulated, the tiny organs expand, intensifying color; when the muscles relax, they contract and pale. The ability to change body patterns rapidly is a powerful tool particularly important to broadclubs, one of the few cuttlefish species that hunts during the day.
>As we trail a few feet behind, the cuttlefish orchestrates its chromatophores to perfection, instantly brightening when it emerges into the light and reverting to a mottled brown when it eases into the shadows. Suddenly the broadclub stops in its tracks only a few inches off the bottom, turns pale and forms a cone with six arms while extending a single arm to each side of its head for stability. To our amazement, it then sends pulsing light bands streaming down its body, much like a flickering theater marquee. Ever so slowly, the tips of two elastic feeding tentacles emerge from the cone. Faster than our eyes can follow, the tentacles shoot forward, and a small wrasse more than two feet away disappears.
>No one is quite certain how the ghostly flashes, known as the passing cloud display, aid the hunt, but in each of a dozen feeding attempts we witness, the behavior, which possibly mesmerizes the prey, is employed before the club-tipped tentacles shoot forward with the speed of a chameleon's tongue. It seems impossible that the sharp-eyed damselfish isn't aware of such a hulking predator hovering less than a meter away, but the fish makes no move to escape before tentacles fly.
>Like so often happens in the sea, as soon as we think we understand the cuttlefish's feeding style, it begins patrolling along the edge of the lava flow just beneath the surface. In a blur of bubbles it strikes the waterline. To our delight, the cuttlefish, as if showing off a trophy, swims to within an arm's length of where we kneel. This time there is no doubt of success; the flapping tail of a blenny extends from the powerful web of arms.
>See the cuttlefish's hunting lightshow in exclusive video by Anna DeLoach.
>See the Video
>© Alert Diver — Fall 2010