A Sea of Glass Page 10
We arrive at the boat, which looks mellow in the days-end light. We set out across the pink-lit sea to our dive spot off Hawaii’s west shore. We are happy to be heading out with Denise and David, since they have been helpful, knowledgeable partners in our Cornell semester program, teaching our students to dive, taking them into their business as interns, and even putting them up during their internships. As we tie up to the mooring in the dark and sort our gear, I’m skeptical that we’ll find either octopus, but I know there will be other interesting critters on the reef at night, and some of them may be Blaschka matches. Once underwater, we hunt with our headlights on in the pitch dark for over forty minutes. We scare up a fluorescent pink flatworm and a slipper lobster. As we nudge past a few sleeping reef fish, I note there are not many on this reef, which has been heavily fished. We are watched all the while by the glowing eyes of resident shrimp. Since my face is pressed close to the bottom, on the lookout for any good finds, I keep getting lost from the group. Suddenly, someone I don’t recognize swims through the darkness, grabs my arm, and drags me along. By now, I am pretty disoriented about where we are on this reef and I have no clue where we are going.
Just ahead I see a large lighted glow from dive lights. There it is—the ornate octopus! Everything runs through my mind at once: disbelief that we have found it, delight that it is there, worry that it will disappear too fast. The octopus sits stolidly in the light of the camera, not too bothered by the attention. It’s an unusual shade of orange with bright white spots and dashes along all its arms. It’s beautiful. I tentatively reach out a finger to touch a tentacle. It touches calmly back with its suctioned tentacles, then scuttles in the other direction, but I easily herd it back between my cupped hands. All the while it watches me with large amber eyes.
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As I mentioned, my adventures beneath the surface all started with an octopus—a glass one (page 1). I remember it eyeing me from its case and I wondered, what makes this work of art like a being I want to spend time with? The Blaschka works have a presence and allure, a sensitivity and flair that reaches beyond the mechanical imitation of nature and becomes the gestalt of nature itself, the soul of nature. This comes out vividly in the cephalopods because they are the one invertebrate imbued with clear intelligence, perhaps even consciousness. The Blaschkas knew this when they put pen to paper to sketch their models. This common octopus, now restored, seems completely self-aware as she gazes calmly at me from her display case.
The Blaschkas’ glass octopus models are infused with an eerie sense of consciousness because of the depth and expressiveness of the eyes. The artistry of these eyes came from long practice, because the Blaschkas’ very first works in glass were prosthetic eyes for humans. Today, at the Corning Museum of Glass, there are bins of different-sized prosthetic eyes that were found in the Blaschkas’ workshop, awaiting adoption by humans in need.
Leopold and Rudolf’s artistic vision captures complex details of biology that are sometimes little known even to me. Only recently have I looked closely enough to notice black, curved hooks bristling from the tentacles of one of our squid models (Ancistroteuthis lichtensteinii) like the poised claws of a cat, or the comical, Dumbolike fins of the chubby Rossia squid. The masterpiece of the cephalopods is the mighty Chiroteuthis veranyi squid, with long coiled tentacles exactly as Haeckel portrayed them in his drawing, and eyes shadowed in periwinkle blue (page 112). Even Haeckel’s dramatic, somewhat stylized rendition of Chiroteuthis does not show this mastery. Since I had never seen a living Chiroteuthis, in preparing for my TED Talk about our collection, I turned to Bruce Robison’s videos of the living Monterey Bay Chiroteuthis, masterpieces in their own right. I knew those long coiled arms were used for prey capture, but I didn’t understand exactly how they could shoot out so fast. Think about the mechanics of it: Those arms are at least four times the body length of the squid, perhaps ten feet long, and there are no bones for muscle to contract against. When humans punch, they use the mechanical advantage of muscles contracting against bone. To punch its arms, Chiroteuthis takes advantage of what we call a hydrostatic skeleton. The longarmed squid contracts muscles to increase its internal fluid pressure, allowing it to squirt out those arms at high speed and nab a passing fish. Squid also use a hydrostatic skeleton for jet propulsion—drawing in water from their siphon and jetting it out under pressure.
The dazzling part of Cornell’s glass cephalopod collection, which includes thirty-seven pieces, is its diversity. We can walk through all the major groups within this class—eight-armed octopus, tenarmed jet-propelled squid (page 117), and eight-armed shapeshifting cuttlefish, then dawdle within the amazing diversity to view tens of species of each (page 118). To this day, Leopold and Rudolf give us the chance to see both common and rare species.
The Blaschkas’ jeweled umbrella squid (Histioteuthis bonnellii) before (top) and after restoration. Many of Cornell’s models are in this condition, from early years when they were not cared for. The transformation is magical when a talented conservator like Elizabeth Brill puts a model back together. Although this species of squid lives deep in mid ocean and is not commonly seen, it does appear in the stomachs of dolphins and sharks, indicating it still swims our seas. Photos by Elizabeth R. Brill (top) and Kent Loeffler.
The cephalopods past and present are all top predators: fast-paced, jetpropelled, active hunters of prey from crabs to fish. In squid, this active lifestyle is supported by four hearts that power a closed, high-pressure circulatory system—a far cry from the open, slow-moving circulatory system of their relatives the sea slugs and bivalves. We call cephalopods jet propelled because their speed is provided by the same muscular body wall that controls the powerful arms. They contract rapidly enough to create an enormous pressure change that jets them through the water.
The actual mechanics of the stunning jet propulsion accomplished by the body wall and its multiple layers of spirally wound fibers and opposing muscles has long been a fascination for engineers (Kier and Smith 1985). The other part of the magic trick is the fastest electrical conducting system known in animals. The giant axon or nerve is beloved of neurophysiologists because it’s large enough to study and it runs the length of the squid; at a millimeter wide, it’s the same width as spaghetti. Larger diameter axons have faster conducting speeds; at eighty-two feet per second, this is the fastest unmyelinated conducting axon known (Plonsey and Barr 2007, p. 109). Humans have smaller-diameter axons, but ours have a fatty covering, called a myelin sheath, that amps up the conduction velocities of our motor neurons to over 260 feet per second. In addition to jet speed and maneuverability, cephalopods have, by comparison to other invertebrates, an unprecedented sensory system: a camera eye that rivals the structure of the vertebrate eye, including our own. This is one of the big evolutionary puzzles—that such a complex structure as the camera eye could have evolved independently twice, in both backboned animals and cephalopods. While the brain of a squid, octopus, or cuttlefish is no larger than a pea, it does serve as a central processing center for this active, highly sensed predator. But the real marvel that I relate to most in communing with cephalopods is their level of intelligence. It’s been suggested that octopuses have, on average, the intelligence of a cat. This is easy to believe when they play games with you from a tank or underwater.
Cephalopods in glass (clockwise from top left): common clubhook squid (Onychoteuthis banksia), stout bobtail squid (Rossia macrosoma), elegant cuttlefish (Sepia elegans), fourhorn octopus (Pteroctopus tetracirrus), curly tentacle octopus (Eledone moschata), and blanket octopus (Tremoctopus violaceus). Photo of curly tentacle octopus by Claire Smith; photos of cuttlefish and blanket octopus by Elizabeth R. Brill; all other photos by Kent Loeffler.
A lesser-known member of the cephalopods are the argonauts, the pelagic octopus called paper nautiluses. In Jules Verne’s novel Twenty Thousand Leagues under the Sea, there is a wonderful picture of Jason on his ship The Nautilus, surrounded by a fleet of argonauts with their
sails lifted. The ancient Greeks believed argonauts sailed on the water by using two of their arms as sails. Because of this, they named the mollusc after the sailors of the ship Argo. They were the sailors who went to look for the Golden Fleece in the famous Greek myth.
The Blaschka watercolor of the male argonaut was initially a puzzle to me. I wondered why Leopold had produced such a small, exquisitely detailed watercolor of a very small argonaut. I thought perhaps it was a juvenile, but after some research, I learned he was portraying, to scale, the one-inch-long adult male argonaut. In contrast, the female is five times larger, lives much longer, and makes the brilliant white, paper-thin egg case that gives these octopods the name paper nautilus (page 121). Our stunning glass female is shown without her normal paper shell, but holding her flat egg cases on specialized arms. The paper nautilus, technically an octopus, is just one of four cephalopod groups that show this extreme size dimorphism between the sexes. Another example is the blanket octopus (Tremoctopus violaceous), which the Blaschkas also sculpted in glass. The males may be only an inch long, but the female can be three feet long. The tiny males in all these dimorphic octopuses do, however, have an interesting aspect to their biology that is included in Leopold’s watercolor of the male argonaut: a detachable heterocotylus arm, which functions like a penis. I have to admit the detachable arm was a new and surprising discovery for me. This heterocotylus arm breaks off from the male and actually swims by itself to inseminate the female (Orenstein and Wood 2015). I thought this was slightly unusual but wasn’t that surprised by it, since invertebrates have some extremely kinky sex by our standards.
While on the topic of sex and reproduction, we need to discuss the Achilles heel, the weak link in the life history of all the magnificent, brilliant cephalopods. All of the females and many of the males are semelparous, which means they only reproduce once in their lives and then die (think Charlotte’s Web . . . ). This seems amazing to me given the degree of social interaction involved in mating and the enormous effort invested by octopuses in brooding their clutch of eggs. For example, our common octopus carefully ventilates and guards her tiny brood for between two and six months, depending on where she lives, and then dies after they hatch. The male will die soon after he mates with her. Their lives are indeed often very short. Even the giant Pacific octopus lives only three to five years in the wild. Considering their level of intelligence and how little time they have to accumulate learned experiences, I reckon an octopus that could live to be twenty might well be smart and experienced enough to take over the planet.
A Blaschka watercolor of a male argonaut (left) and a Blaschka glass model of a female argonaut (Argonauta argo). Watercolor and photo courtesy of the Rakow Research Library, Corning Museum of Glass, BIB ID: 122439.
But of all the cephalopods’ remarkable traits, there is one that researchers are still trying to wrap their heads around: the ability to quickly shape-shift, or transform, from a rock to a piece of drifting algae. For example, cuttlefish are called chameleons of the sea because of their split-second color and shape shifts. Watching two cuttlefish together is like watching a conversation in color. In competing males, low mutters of muted shades change quickly to emphatic shouts of sharp, dark colors. Passionate love calls between mating pairs are shared in vibrating colors that wash along the body. It boggles the mind to see two conversations occurring at the same time on a single animal; I once saw a male cuttlefish crooning a colorful love call to a female along the side of his body facing her while simultaneously edging out a male with a sharp, jagged territorial display on the other half of his body. The rather serious octopus scholar Roger Hanlon made his audience laugh with the joke that this type of two-part conversation is evidence that males have been two-faced from earliest evolutionary time.
The uncanny camouflage of octopuses and cuttlefish requires large but precise color and body surface texture changes. Sacs of yellow, red, brown, and black pigment called chromatophores are opened and closed by muscles that orchestrate instant, coordinated color changes. Muscular contractions change skin texture from as smooth as glass to as craggy as a drift of algae. The degree of shape and color matching of underwater objects is a conjurer’s trick. It includes all the color and shape changes and behavior that mimics exactly the object being imitated—for example, mimicking a coconut shell bouncing along the ocean bottom or a piece of algae floating by. Once, on a dive to a very scroungy reef near a fish farm in the Philippines, I saw a foot-tall piece of floating algae start to swim purposefully away and realized it was actually an octopus. Once we started to watch her, she gave this “Uh oh, busted!” kind of shrug and went through a frantic series of shape and color matches to everything around her, from rocks to algae to coral heads. How strange to realize that in this riot of color change, octopuses are, themselves, color blind.
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Octopuses in Hawaii. Drew holding the ornate octopus (Callistoctopus ornatus) on a night dive (top) and trying to entice the day octopus (Octopus cyanea, a close match with the common octopus) from its den. Photos by David O. Brown.
David was right—it is pretty easy to cage an octopus between your hands—at least until it jets off over your head. But it is easy enough to follow this one swimming off into the night. This time, as I herd her again, I’m braver and ready for the jetting trick. As she lifts off, I catch her gently in midair, almost like some large bird, except one with eight sticky tentacles. Holding her at eye level, I look into her eerie, knowing eyes (above). Then a tentacle slaps onto the front of my mask, and the octopus crawls up my arm. I feel like the octopus whisperer.
This is the moment I fall in love again with the unexpected, otherworldly, and profoundly beautiful biodiversity in our oceans—this animal is so exquisite in form, so interesting, and so unlike anything else on the planet, it’s heartbreaking to know that we are systemically, and often wantonly, destroying it and its world. I relish all my invertebrate field experiences, but this one stands apart. Luckily for me, we’re going to dive again the next day. The strategy for our next dive is to be up before sunrise and in the water with the rising sun, hoping the day octopus will be venturing out.
We arrive before the sun at our shore site on the wave-crashed Kona-Kohala coastline. It is always a bit tough to clamber over the sharp lava rock laden with heavy tanks and dive weights, but we make it underwater as the sun rises. The morning glow illuminates a crystalline seascape filled with bright yellow tang fish, autumn-colored coral heads, and large lurking trumpet fish.
Looking for an octopus that doesn’t want to be seen can be a tough prospect, so I am prepared for a long hunt. It seems so improbable as to be fated, because within minutes of entering the water, I spot a dark brown smudge on the edge of a coral. The smudge ripples, transforming what at first looked like rock face into a foot-and-a-half-tall camouflaged octopus. I can’t believe that we are so lucky as to have found the exact animal we wanted right away. As we approach, the cat-sized octopus withdraws partly into its den. But it is bold and actively watches us, soon easing back up along the rock, tentacle by tentacle.
It’s clearly curious, elevating periscoped eyes as high as possible to watch us from beside the den. As I move away, it eases out further, craning its eyes to watch. It’s quite comical. After a while, it settles and stays put, body flickering through a kaleidoscopic color change from beige to deep brown to a mottled paisley.
I try to entice it out by running my fingers back and forth and then tapping on a rock, like playing with a cat (page 123). No dice. It eases up a little further from its burrow and cocks an eye, but no tentacle reaches out to sample my game. Meanwhile, trumpet fish, attracted by David’s camera lights, have gathered to watch the drama as David tries to film, laughing as he steadies the camera.
I move away a bit to see what happens. No sooner do we ease back ten feet or so than the octopus, far larger than I had realized, lifts off its rock stronghold and jets across the reef. What a spectacle—a big octopus, in full swim with long
tentacles trailing three feet behind the massive webbed body. In stealthy pursuit, we watch as it settles again to the reef, with a fast-paced race through its repertoire of colors, this time from brown to maroon to beige to vibrantly striped and back to brown.
This is my chance. As the octopus lifts off again, I reach to catch it in midflight. After the easy time I had with the delicate ornate octopus the night before, I am unprepared for how strong this big one is, and there briefly ensues a bout of extremely uneven interspecies grappling. Through a rain of tentacled suckers, I try with two arms to hold eight. As if that wasn’t enough, we are both suddenly engulfed in a huge, blinding cloud of dark brown smoky ink. I can say from firsthand experience that inking is the strategy to confuse a would-be predator. This marine Houdini eluded me in seconds and was once again across the reef and into the safety of another den.
David continued trying to film this, but as I looked over, we both flooded our masks laughing. He had just filmed a ridiculous spectacle of me rolling around on the sand with this octopus, ending with us both enveloped in ink and the octopus calmly jetting off. Although the dive ended abruptly, we left pleased to have found both of these octopuses so easily. Despite strong hunting pressures in the Hawaiian Islands, they seem to be doing well.