In honor of World Ocean Day this June 8, I’ve decided to write about something marine. Not one of the few and proud but a marine snail. I was inspired while scuba diving the other day and catching a California cone snail (Conus californicus) in the act of spawining. Reproduction in cone snails has not been widely studied but the sexes are thought to be separate, with fertilization internal. I watched as transparent egg capsules carrying minute snow-white eggs were extruded and laid on the mud bottom. Cool! Our local cone, one of many cone snail species found in marine environments throughout the world, lives in sand or reef habitat from San Francisco to Baja California. Its sturdy ice cream cone-shaped shell (wide at one end and narrow at the base) is yellowish-brown with a faint white band, and three-quarters to an inch-and-a-half long. The strong, muscular foot is yellowish with black and white markings. Jutting from the shell’s narrow base are a pair of eyes set on stalks and a Pinocchio-like nose called a proboscis (really, a siphon), which is transparent with black and white markings. A California cone preys on worms, other snails and small fish. To catch prey, it may engulf the victim, sting the victim or combine techniques like in the following example, which shows that even if a cone travels at, well, a snail’s pace, it can still enjoy fast food. The cone snail meanders along, waving its seemingly innocent proboscis in the water like a conductor’s baton, but the sneaky siphon instead harbors weapons of fish destruction. Within the hollow tube lies a harpoon-like tooth, which partners with venom to skewer and paralyze small fish passing nearby. The sequence of events begins when a cone snail first captures the scent of a fish via chemical receptor cells found on the proboscis. The proboscis then gently touches the prey and, in less than a third of a second, the proboscis contracts and fires the tooth (which is attached to the siphon by a thread) into the prey. The final blow comes courtesy of the subsequently injected venom where, within seconds, the prey is immobilized. The tooth’s job isn’t done yet. It is now employed as a hook attached to the fish, so that as the thread is retracted back inside the proboscis, the prey comes with it. Think of it like fishing with a hook and line where the catch is snagged, then reeled in. After this process, at least in the cone snail’s case, the prey is engulfed through the widened proboscis and moved to the stomach for digestion. The entire scenario, from detecting the prey to stabbing and stunning it, takes less than 300 milli-seconds. How fast is that? Let’s just say that Dirty Harry is an amateur next to the cone snail’s quick draw. This ballistic maneuver, unique to the animal kingdom, demonstrates how a slow predator can catch such fast prey and likely evolved to allow the snail a wider selection of food options. During the last few decades, cone snails have shown potential in neuroscience research and drug development. Cone snail venom is very complicated chemically and varies widely in its composition from species to species. The venom, which has hundreds of active components, is a potent neurotoxin that first causes numbing or tingling at the site, then spreads to the whole body. A small number of hapless beachgoers inadvertently injected by some of the most toxic cone snail species have suffered injury and even death. Under other circumstances, however, the outcome is very different. In 2005, the FDA approved two drugs synthesized from the venom of cone snails to treat severe, chronic pain. These drugs are reported to be non-addictive and 50 times more effective than morphine. For centuries, cone shells have been collected for their unique and intricate designs, placing them in danger of being over-harvested by collectors. Now that cones are also heavily collected by scientists searching for new venoms, there are two reasons cone populations risk depletion. Presently, no cone snail species are listed as endangered or threatened, although there is increasing concern among scientists that some species should be listed, and some countries have adopted regulations governing their collection and sale. — Judith Lea Garfield, biologist and underwater photographer, has authored two natural history books about the underwater park off La Jolla Cove and La Jolla Shores. www.judith.garfield.org. Questions, comments or suggestions? Email [email protected].