The Rhino with Glue-On Shoes (18 page)

Sliced Bananas in Jell-O

by Michael Stoskopf, DVM, PhD

W
hen did it start?”

“I don't know for sure. Two weeks ago she was a bit slower to come out. Not as aggressive as usual. Now she isn't eating at all. Is it happening already?”

“I hope not. It shouldn't be. She isn't that big yet, but this is how they say it starts. The whole thing doesn't make much sense to me.”

“To me either, Doc, but they sure are delicate. We've had Bertha months longer than any of the others, and everyone says they only live three years. When she got to Baltimore last year [1984], I'm sure she had to be at least a year old. They don't grow very fast when they are here. I'm guessing she is between two and three years old.”

“I don't get it either, Doug, the whole thing is strange. Endocrine glands suddenly enlarging beside the optic nerves, and then—instant senility. It doesn't seem right. I know nature is stranger than fiction, but I'm not sure I can buy into such a large and intelligent animal being essentially disposable. They have to live longer in the wild. Besides, the first ones we had arrived nearly dead, did poorly in our water, or injured themselves escaping. We've only seen the large optic glands on one animal, Ollie, and he was a male, and much larger than Bertha. Maybe the glands aren't the issue at all.”

“Maybe, Doc. I hope you're right, but what do we do with Bertha?”

While we talked, Doug, the senior aquarist in charge of the octopus gallery, didn't break his steady observations of the giant Pacific octopus, Bertha. Bertha sat holed up in her favorite large broken crock, holding herself in position with her large suckered tentacles. Her expiratory siphons moved rhythmically, bringing oxygenated water past her gills. Her color was a vibrant mottled red with black patterns, a good sign. The earlier animals had become pale a few weeks before their deaths. There also was no evidence that Bertha was picking at herself—yet. We had watched Bertha's predecessor, Ollie, pull at his own flesh, creating large irregular ulcers on his mantle. A few weeks later he finally died, despite our best efforts to treat the wounds.

If it weren't for Doug's intense familiarity with Bertha's moods and habits, no one would suspect anything was wrong with her. Maybe it was something simple like indigestion, and not the fatal octopus endocrine senility syndrome. I'd found this strange syndrome described in a fifteen-year-old article in
Science
magazine. But if Bertha's problem wasn't senility, what was it? How could we find out what the problem was?

The aquarium had struggled to learn how to house these big, intelligent invertebrate animals. First there were the shipment problems. The very large wild-caught specimens didn't do well on cross-country trips from their northern Pacific range, even when shipped inside specially designed high-tech life-support barrels. If your aquarium wasn't on the West Coast, then catching and shipping smaller animals was the only answer. Unfortunately, octopi that arrived in good condition then proved capable of escaping from the exhibit with impunity.

They could maneuver through unbelievably small cracks between the heaviest tank lids and the exhibit walls. Once out of the exhibit, they'd be stranded on the floor behind the exhibit, without access to saltwater. Though the escaped animals would be found alive when the aquarists came in early in the morning, they never fared well afterward. When heavier lids on the exhibit didn't solve the problem, we lined the top of the exhibit with artificial turf, a plastic material that prevents the eight-tentacled, Houdini-like animals from attaching their powerful suckers to gain purchase to allow them to squeeze under the display lids.

The escapees taught us something else. Sometimes it was hard to tell if the octopus was alive. One of the first animals to escape was found lying apparently lifeless on the floor in a back room near its tank. The octopus was pronounced dead and delivered in a sealed plastic bag to the pathologists at the university. But when the pathologist took the supposedly dead animal out of the refrigerator and started to prepare for the necropsy examination, the octopus reached up and grabbed the arm of the startled scientist. A police car, sirens blaring, escorted the animal back through the city to the aquarium. Sadly, several days of supportive care, monitoring, and all of our efforts to revive the animal met with no success. But I did learn a great deal about octopi in the process, like how to take a blood sample and how to read an octopus EKG.

At first glance no one would think of Bertha as delicate. However, like other cephalopods, giant Pacific octopi are very sensitive to tiny amounts of toxic metals and slight imbalances of essential elements in their water. And the water must be cold. Facilities successfully keeping these animals alive for long periods in the past all had natural seawater pumped into their exhibits, an advantage we didn't enjoy. Keeping giant octopi healthy with artificially made seawater posed many unexplored challenges. Water that is perfectly suitable even for delicate corals, another type of aquatic invertebrate, can prove problematic for an octopus. There's also the difficulty that when octopi become agitated, they release a dark plume of chemicals popularly known as ink. In the wild, an octopus uses this discharge to befuddle prey or to serve as a distraction while escaping its own predators. The ink contains several neuroactive compounds that cause disorientation and confusion. An octopus in the wild would normally move rapidly away from an area it had inked to avoid being affected. In the exhibit tank, of course, that isn't possible.

Fortunately, Doug had been able to solve the water issues. He was one of those people who just seem to have a “green thumb” with delicate marine creatures. It wasn't simply his careful attention to detail, or his deep curiosity about the animals, it was also a gift for understanding the needs of his animals that every great aquarist or zookeeper seems to have. Thanks to many expensive sophisticated water tests, Doug found and removed all sources of heavy metals from the exhibit and refined the artificial seawater mix. He also figured out ways to reduce the anxiety caused in these intelligent animals due to their being on public display by giving them better hiding places and more things to manipulate, and lowering the light levels in the gallery. This effectively reduced the risk of an inking event. These advances had allowed Bertha to live longer than the octopi before her, and long enough for us to suspect the rapid senility syndrome that we had first learned about while trying to save our previous giant Pacific octopus, Ollie.

Ollie had survived the early adjustments and lived apparently comfortably in his exhibit for nearly a year before he suddenly stopped eating. He then became listless, tearing at himself and opening the wounds we weren't able to heal. We made a number of advances in octopus medicine while trying to diagnose and treat Ollie, just not enough of them.

In veterinary medicine, blood samples often help us make a diagnosis, and I take pride in being able to get blood from even the most challenging of patients. I had figured out how to draw a blood sample from an octopus using landmarks I noted while dissecting the bodies of the less fortunate earlier animals in our collection. To take a sample from Ollie, one aquarist would hold on to a tentacle and pull it out of the water, while another tried to keep the animal from climbing up and biting with his strong beak, which is capable of cracking a crab shell with ease. When I inserted a needle directly into the vein supplying the tentacle, I could withdraw several milliliters of clear, slightly bluish blood. In relative terms, getting a blood sample wasn't that hard. Unfortunately, the analyses weren't very informative. No one had published what the blood of a normal giant Pacific octopus should look like. Nor was there any obvious pattern of change in the chemical composition or cell types when comparing the samples taken over the many weeks that Ollie refused to feed.

As his condition deteriorated, I found an article published many years before in the journal
Science
about a smaller species of tropical octopus being used in research. The paper described two large orange glands adjacent to the optic nerves that appeared just as the smaller octopi reached sexual maturity. If the glands were removed surgically, the article reported, the octopi could be induced to live longer and survive the reproductive stage of their lives. When Ollie died, we found those orange glands at the necropsy. We hadn't seen them in any of our earlier animals.

Could surgical removal of those glands save Bertha, or at least extend her life? Normally I'm willing to try radical measures to help a patient in crisis, but I hesitated to perform what amounted to delicate brain surgery on an animal whose illness consisted, so far, of missing a few meals. Besides, I had my own doubts about the supposedly “lethal” nature of the orange optic glands, despite the prestige of the journal
Science.
It seemed unlikely that this large, magnificent, and intelligent animal should be doomed to a single reproductive cycle and then senescent death.

On the other hand, I wasn't going to simply watch and wait. When working with any new species, my instincts tell me it is better to get on the case sooner rather than later. Bertha continued to refuse her crabs and any other tasty treat Doug could find to tempt her. Were her optic glands in fact enlarged? It was time for some creative diagnostic testing like octopus radiography to try to see the glands.

It wouldn't be easy. As far as I knew, no one had ever tried to anesthetize and position a thirty-five-pound water-breathing mass of muscle and intellect for an X-ray. The aquarium's small portable X-ray unit wouldn't be able to penetrate Bertha's body mass and give us the detail we would need to see if the glands were enlarged. That's why having a faculty appointment in the radiology department of a world-class medical school comes in handy. Time to call my friend Elliot and arrange for a CT scan.

Tall and blond, with a bristling mustache and darkrimmed glasses framing his face, Elliot always seems to be in motion. While nurses and technicians efficiently put his human patients into the CT machine and generate images at a dizzying pace, Elliot choreographs it all and dictates incessantly into his recorder, interpreting the images and making life-impacting diagnoses. He is amazingly skilled but, more important, he is curious, and always makes time for my non-human patients. And his CT machine is fast. We would only need to keep Bertha still for a few minutes to collect many images of her.

I had learned a valuable lesson that would help me safely anesthetize Bertha from the wild ambulance return of the not-yet-dead octopus years ago. To protect the expensive CT equipment, we would anesthetize Bertha lightly, just to the point where she could no longer grab with her eight arms. Then we would put her in a plastic bag with some water, place her in the scanner, and quickly acquire images of her head region. Special software that Elliot and his research team had developed would allow us to reconstruct the images into a three-dimensional view. This would compensate for our inability to position Bertha precisely.

Over a period of nearly thirty minutes, we carefully induced Bertha's anesthesia. Then it was splash, zip, zap, and we had the images. Helping my technicians to extricate Bertha from her bag, I called to Elliot, “What do you see?”

“A bag full of Jell-O with banana slices all through it,” Elliot called out over the intercom.

Sure enough, the CT scanner, which is very good at many things, didn't find enough differences in the density of Bertha's tissues to make useful images. Her powerful, muscular suckers showed up like big slices of bananas against a uniform gray background. Only her strong beak was discernible. We would have to try something else, maybe MRI—magnetic resonance imaging. MRI works on an entirely different principle than X-rays or CT scans, and provides a much better view of soft tissue structures. But it takes longer to make the images, and Bertha could not move during the imaging. Bertha would have to be under anesthesia for a longer time.

The challenges of applying MRI technology to an octopus might have been more intimidating, but for years I had been a member of the research team that was developing better methods of using the big magnets for diagnosing a wide range of conditions in humans and in animals. I knew the images we could obtain with the equipment would be far better for what we needed to see than CT, but I worried about subjecting Bertha to the longer and deeper anesthesia we would need to get those images. I had hoped the faster CT would do the job. Should we just take Bertha back to the aquarium and watch her behavior? Or should we try to keep her anesthetized in the bag long enough for an MRI?

Blackie, my wiry and very humorous British teammate on the MRI group, made the call. “Aw right now, in she goes, where she stops nobody knows. Just don't spill any water on me magnet.”

Back into the bag went Bertha, this time with a bit more water. Blackie wasn't kidding. Any spill would ruin the multi-million-dollar research instrument. On top of that, the saltwater would dampen the signals in the machine. Luckily, our MRI development team had done something like this before. To improve the image quality for marine creatures, we'd built several special acquisition coils to collect signals from other animals that lived in saltwater. (They don't teach you this stuff in veterinary school!)