MW553 - Hell's Gate - Nature
(A) Normal backward swimming; October 2000 Dominica; copyright Ned DeLoach. (B) Apparent flounder mimicry; October 2000, Dominica; copyright Paul Humann. (C) Apparent flounder mimicry; December 2004, Saba. Photo by M. Chammaa. These are the images included in A “Mimic Octopus” in the Atlantic: Flatfish Mimicry and Camouflage by Macrotritopus defilippi | The Biological Bulletin: Vol 218, No 1 (uchicago.edu)
Although Saba has five species of daytime foraging octopus, it doesn't mean they will come out and prove it just because you brought in a cephalopod expert. We knew they were likely there, but after a few futile days searching for these masters of disguise on our reefs, we headed over to the sand flats. Local diver and chef, Michael Chammaa, was on the dive and thought he saw eyes peering at him from under a conch shell. Then it moved. But it was now scooting along with its body flattened to the sand. The Atlantic longarmed octopus, Macrotritopus defilippi was acting like a Peacock Flounder! As Michael and Dr. Roger Hanlon of Woods Hole Oceanographic Institute followed the octopus across the sand, they made a surprise discovery. Saba has a mimic octopus! Why the surprise? Mimicking behavior of octopus was thought to take place only in the South Pacific.
The discovery occurred in the early days of Sea & Learn, (December 2005), when we had funding to do additional projects outside of our month-long October event. Antillean Co-Financing Organization, better known as AMFO, allowed us to do three cool things besides the octopus search. Professional spelunkers came to Saba to dispel the myth that a cave accessed from the Whale's Tail took you out to the Saba Bank. Saba Conservation Foundation ("SCF") Junior Rangers participated in a week-long Outward Bound-style program led by famed safety advisor Jeff Bozanic and his physician wife. And if that wasn't enough, four lucky Saba kids, chaperoned bySue Hurrell, participated in a rainforest summit in El Eden, Mexico. In addition to experiencing the wilderness of Central America with other students from around the globe, Team Saba did a presentation about Saba's cloudforest. Finally, we were able to squeeze in a mini project to measure sedimentation issues at Tent Reef.
Octopus are trending. But their reputation is two-sided. One the one hand, they are heralded as "the smartest animal in the ocean" but on the other, they are accused of being aliens. They are the stars of biomimicry. My Octopus Teacher won an Academy Award (aka "Oscar") for Best Documentary Feature, spotlighting this remarkable creature. They are a reason to learn to dive and to dive more!
A scuba diving "career" encompasses a few stages. First you are wowed that you can actually breathe underwater. Then there is the wonder of seeing a whole new world. With more experience (just doing more dives) this all becomes more natural. Soon after that you start to almost ignore all the usual suspects on the reef and yearn to discover the atypical. The next stage for many is the photographer stage. Francoise Giacalone and David Da Costa have enjoyed diving in the Saba Marine Park since their first visit in 1995. They are avid photographers who find joy in capturing the perfect underwater moment. After returning to the island more than twenty times, they are now Saba homeowners and the proud sponsors of the octopus storyboard, Octo-Genius.
Back to that octopus......why did we go to the sand flats to begin with? Because it's our muck diving spot. Muck? Muck diving is diving in unlikely places--for example, sand flats, beneath a dock, or in an area known to be littered. Former Sea Saba owner, John, traveled to remote waters to find the strangest underwater creatures only to realize, there was some pretty interesting muck opportunities in "his own front yard", the mooring field outside the Fort Bay harbor. Putting your boat out to float each night requires confidence in the mooring system and regular checkups. Saba's boat moorings are on a sandy shelf, far from any other dive site. Yet many unusual creatures had found refuge around the mooring blocks and on bits of discarded chain. Huge starfish not seen elsewhere in the park were normal in the early 90's but the frogfish, seahorses, batfish and octopus were worth the extra time once the mooring duties were fulfilled. This is the area where the mimic octopus was documented. Today the mooring field is far different, carpeted in an invasive seagrass, providing a new habitat (and critters) to explore.
Over the years, Roger Hanlon has returned to our October program delivering his Hollywood-level presentations. His footage of octopus behavior astounds our audiences. Start here to watch a variety of videos showing the octopus' ability to deceive its predator by changing shape, color, patterns and textures--and so quickly! Hanlon's work has been used in several tv series, and he's even collaborated with NASA whose interest lies in studying the arm movement of octopus.
Scroll back to page 67 for the start of the Sport Diver article that includes diving with Hanlon on Saba: Naturally Saba, where the wild things are in the Dutch Antilles. For a full read of the scientific papers by Hanlon on mimicking behavior: A “Mimic Octopus” in the Atlantic: Flatfish Mimicry and Camouflage by Macrotritopus defilippi | The Biological Bulletin: Vol 218, No 1 (uchicago.edu)