Venomous Scorpionfish and Predatory Snails - Masters of Camouflage

I am always impressed at the remarkable level of camouflage that can be exhibited by marine organisms. These photos show a few of the masters. These were photographed during a recent dive at Isla San Pedro Nolasco, near San Carlos.

This first image is of a snail that proved incredibly elusive for me. I looked for this beautiful parasite on and off for over a year! It wasn't until I brought along a flashlight that I was able to see it against the backdrop of its coral home/prey.

The snail is Epitonium billeeanum, a relative of whelks. It spends its entire life living among colonies of the sun coral, Tubastraea coccinea, where it passes its days slowly consuming the colonies and laying copious masses of eggs (the yellow clump over the snail). These in turn will hatch on a ready-made feast for these tiny snails.

Relying on exquisite camouflage and a nice array of venomous dorsal spines, the stone scorpionfish, Scorpaena mystes is reluctant to move when divers approach.

I've been stung three times by these fish - once during an underwater rescue when I placed my hand on a fish to get some leverage - thinking it was a rock. The other 2 envenomations occurred while handling these fish in my lab. Their toxin is very good at lowering blood pressure. In my case they were a little too good. The third sting required a long series of injections to keep my heart rate up.

Silhouetted against the water, scorpionfish are easy to see, but against the backdrop of the seafloor, it's easy to see how they might be mistaken for a rock.

Cold Water & Killer Whales

The winter water has begun to find its way into the San Carlos region. So with water temperatures dropping below 70 degrees, the question for warm water sissies like myself becomes “is it worth it”? Sure, California divers may scoff at such a question. 65-68 is downright balmy along the Pacific coast, but you need to realize, I wear a 5 mil just to teach scuba in the pool… a pool that is heated to 82 degrees all year long. While I may shudder at the thought of that first dip under, when the water creeps down the spine of my wetsuit, there is no doubt as to whether it is worth it. Despite my reluctance to even look at cold water, much less submerge; the winter diving in San Carlos is simply amazing. In this case, my inner marine biologist manages to beat up my inner water wimp. Of course wearing a dry suit has helped sway that battle a tad.

There are many reasons to go diving in the Sea of Cortez during the winter; increased species diversity, no packed boats, and pleasant air temperatures. But one of the big reasons to go has already shown up…Orcas! The Sea of Cortez is home to several resident pods of these beautiful creatures, and during the winter months they may be sighted cruising the shores of the central and northern Gulf. Divers in San Carlos have already been able too witness pods of these cetaceans at the surface, exhibiting their characteristic playful behaviors.

Orcas aren’t the only cetaceans whose abundance goes up in winter. These cooler months are prime season for viewing fin whales, grey whales, sperm whales, and even humpbacks and the largest mammals in the world arrive, blue whales. That is to say nothing of the superpods of dolphins that may aggregate in the wintertime.

The cool water brings with it the nutrients necessary to fuel the Sea of Cortez for another year. As the nutrients feed planktonic organisms, these in turn are devoured by larger species that follow this microscopic smorgasbord. Crustaceans are tasty staples for everything from migrating whales to diminutive Catalina goodies, a spectacularly colored fish seen only in cool water. Everywhere the reefs come alive with life as the winter bounty is consumed to make for a successful spring breeding season. Winter is truly the time to see the Sea of Cortez at its most vibrant.