Tag Archives: dolphins

Cheetah prosthesis, dolphin tails and the russian space program. Here’s a few follow-ups.

Photo credit: Pieter Hugo for The New York Times

-Yesterday, when I opened the New York Times, I came across the photo of athlete Oscar Pistorius along with the article The Fast Life of Oscar Pistorius – NYTimes.com. It made me very happy. Pistorius wears two Flex-Foot Cheetah leg prosthetics and will soon be competing for a chance to go to the Olympic games. Key thing here: I don’t mean the Paralympic games,  but at the actual Olympics. If he succeeds, he will be the first person without legs to compete.

-Still on the topic of prosthetics, we move on the prosthetic tail for the dolphin Winter, which I described previously. Coincidently, a week after my post, onboard of a plane, the on flight movie was “Dolphin Tail”. The screenplay is embellished, exaggerated, fictional and inaccurate. So you can have an idea: a 10-year-old boy is the hero, who rescues the dolphin and devises the whole prosthetics enterprise. Anyways, it was still worth it to see Winter swimming around (she played herself in the movie). As I pointed out earlier, she does curve her tail to the side, and swims with a sideways motion, as opposed to the up-and-down of most dolphin tails.  That novel movement was causing strain in her spine, and therefore created the need for the prosthetic.

Last week, Phobos-grunt crashed into the Pacific ocean. You might recall from my earlier post (or from several media outlets) that the Russian space agency was sending a craft to land in one of the martian moons. The goals was to collect soil samples and study the effect of radiation in microorganisms onboard. Sad.

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Life imitates art: dolphin and dragon get prosthetic tails

The dragon Toothless (from the movie "How to Train your Dragon") was outfitted with half a prosthetic tail.

Are dragons and dolphins trendy? In recent movies, at least. “How to Train your Dragon” and “Dolphin Tale” both show animals – fictitious or otherwise – who lost their tails and received a prosthetic equivalent.

Dolphin Winter and her prosthetic tail. Image from Hanger Prosthetics and Orthotics.

Prosthetics help not only humans

Years ago I started my undergraduate degree in Computer Science with the goal of designing prosthetics. I took human anatomy and digital circuit classes, and studied lots of biology and robotics. But you never know what life will throw at you, and in that case, it sent me the love for the microscopic world. I became a biophysicist and let’s just say I was more involved into designing drugs as oposed to designing prosthetics.

But the topic still fascinates me. Alongside with drugs and other medicine technology  (think vaccines, anesthetics, or surgery techniques), a prosthesis is something that can dramatically improve someone’s well being. And now, it can improve animal’s quality of life as well.

Dolphin Winter and her prosthesis in detail. Photo by Wired Magazine

Animal Robotics

In september, Wired magazine showcased an article depicting animal recipients of fantastic prosthetics (check out the gorgeous photo above). The piece was written by Emily Antes, and she describes the inspiration behind it in her blog. Among those animals is the dolphin Winter, who lost her tail (or fluke) in a fishing net, and was outfitted with a rubber-like tail and gel socket by the Hanger Team (specifically by Dr. Kevin Caroll and Dr. Dan Strzempka).

Dr. Kevin Caroll ajusts Winter's prosthesis. Photo by the Hanger group.

The Mechanics of a Tail

Dolphins have been on my mind lately. Coincidently or not, after I read the Diana Reiss book on dolphins mirror recognition test (which I wrote about here), my husband took me to the Baltimore Aquarium for my birthday, which houses Reiss’ lab. We were able to see her dolphins, many who participated as experiment subjects I read in her book. Before the Baltimore Aquarium, I had only seen dolphins swimming around my father-in-law’s boat – a pretty amazing experience, however I only got a glimpse of their dorsal fin. This is why, among all animals equiped with prosthesis, I became so captivated by Winter’s case.

Winter’s complete story can be found in the orthopedic clinic that designed her prosthesis. Creating a prosthetic tail was a huge undertaking: the team developed a fluke equivalent, plus a joint that connects it to the dolphin’s tail and allows moviment in several directions, thus mimmicking the animal’s swimming. Besides, the prosthesis needs to be adhered to the dolphin’s body with a substance that won’t dislodge when in contact with water. The team designed a chemical that keeps the entire prosthetic in place, and then named it Wintergel. In some of those amazing real life histories brought by science, there are already success stories of humans benefiting from Wintergel, such as athletes who suffer from friction caused by sweat.

This is vacation at my dad's house: researching dolphins on the big screen.

Science from Aquariums

There is a live webcam feed where you can see Winter swimming in her tank at the Clearwater Marine Aquarium in Florida. In order to watch, you will have to go through one commercial, but it is pretty fun to watch the dolphins swimming.

I have worked in an Aquarium and visited several others throughout the world. So it might not come as a surprise that I had a lot of fun watching the live feed from the Clearwater Marine Aquarium. The picture above shows how my dad and I  conducted our scientific observations: we kept the live feed on the TV throughout the day (in the Russo family, that is called vacation).

By the time I watched, Winter was swimming around without her prosthesis. We noticed, however, this fact didn’t keep her from swimming around and playing with her red ball (her companion seemed more interested in a blue ring toy). Sometimes it looked as if she curved her tail to the right. I am no expert, but it seems this dolphin is getting along. I asked the other Dr. Russo what would be the advantage of giving the dolphin a new tail  – asides from tremendous advancement in technology and insights into human prosthetics –  to which she hypothesized: so she can jump! What an interesting insight. Would love to see it live though. Maybe on my next trip to Florida.

Even fictional characters get prosthetics; Here's toothless'.

Mirror mirror on the wall: who is the most self-aware of all?

(Photo credit: Diana Reiss for Scientific American)

What happens when you place a mirror inside a dolphin tank? Diane Reiss performed that experiment with bottlenose dolphins, and described the results in the book The Dolphin in the Mirror.

The mirror self recognition (MSR) test has been designed to identify self-awareness in animals. When looking at the mirror, can the animal interpret the image as a reflexion of another animal (as opposed to some meaningless image)? Can it associate that animal with himself? Identify himself as an entity? The mirror test is a simplified way to answer those questions, and was originally created by Gordon Gallup in the 70’s. Chimps were the first to pass the mirror test, followed by the remaining great apes (orangutans, gorillas), bonobos and gibbons. Here’s a baby chimp during the mirror test:

Are primates the only animals with self-awareness?

Dolphins have large brains, complex social structures, and ability to express empathy. Could self awareness be added to that list?  A dolphins starts to seem like the perfect candidate for the mirror test.

Marten and Pasarkos initially applied the mirror test in bottlenose dolphins, followed by Reiss and Marino, who published their work in a PNAS paper. In both cases, mirrors were placed inside the dolphin’s tanks. Marten and Pasarkos mentioned the dolphins quickly respond to the mirror, and described their reaction as: “when a dolphin looks in a mirror it often opens its mouth and moves its head around in some rhythmic fashion”. For the authors, it seems clear that the dolphin is  looking at himself, instead of randomly swimming around. Diane Reiss went a step further and replaced the tank mirror with a much smaller one, in the hopes to quantify time spent by the dolphin in that small section of the tank. The book publisher released some of Reiss’ videos os dolphins in the mirror, so you can see for yourself:

To make sure the dolphins were looking at themselves, Reiss performed the mark test: she applied visible marks and invisible sham-marks (with zinc oxyde or harmless markers) in the dolphin’s body, as shown in the picture below.

(Photo credit: Reiss & Marino, PNAS 2000)

After marking, the dolphins would immediately inspect themselves in the mirror, positioning their body so they could see the mark. Primates would also touch and scratch the mark, but this proves difficult when an animal has no hands. Reiss and co-workers saw the dolphins rubbing their head at the tank walls after marking, presumably trying to remove the mark they just saw in the mirror.

Perhaps the dolphin is not the perfect candidate after all. How do we  translate the mirror and spot test for dolphins, who have no hands and live in an aquatic environment? Perhaps the mirror test is not a perfect test. How do we adapt the test? Dolphins spend less time in front of the mirror than primates, and Martin and Pasarkos attribute it to the fact that dolphins are more “mobile” and less likely to stand still in front of an object. They are also highly social, so their interest in the mirror decreased with the increasing presence of other dolphins. Those are signs of emerging challenges when analyzing a marine mammal with a test that was designed for a primate. (Orcas were also studied, with similar results).

(Photo credit: Plotnik et al, PNAS 2006)

Enters an animal that, even without hands, has a structure adapted for touching and inspection of a mark: an elephant’s trunk.

Diane Reiss went on to collaborate with an elephant self-awareness study. Elephants then passed the mirror test on 2006 (See mirror placement scheme in the image above), and the findings were published  by Plotnik et al (PNAS 2006). Elephants also have big brains and display complex social behavior, and exhibited analogous mirror inspecting behavior when marked:

(Photo credit: Plotnik et al, PNAS 2006)

Curiously, a non-mammal has also passed the mirror test: a magpie (a bird from the crow family). Magpie on the mirror was published by Prior et al in 2008, and the pictures below show a yellow spot marked on the bird, and its inspection behavior:

(Photo credit: Prior et al, PLoS Biology 2008)

(Photo credit: Prior et al, PLoS Biology 2008)

The mirror test, however, is not universal. It is argued that this test is not an absolute measurement of self-awareness. An animal might not know what the mirror is, or not be interested in investigating spots (people suffering from Prosopagnosia – inability to recognize faces – also do not recognize themselves in the mirror). I still think it is a somewhat straightforward way to gain insight into many animal species. I wonder who is going to pass the test next!

More cheetah-speed notes

  • Last Friday I attended the “HOT” (Human Origins Topic) event at the Smithsonian, where Dr. Jibril Hirbo and Felicia Gomez gave a talk about genetic variation in african populations and its possible correlation with cultural and linguistic spread. The speakers were very gracious and interesting. I will bring up their papers in a future post. Update: my commentary plus an analysis of lactase persistent trait in african populations can be seen here.

  • I also bought these three books in the Smithsonian bookstore: The Dolphin in the Mirror (Diana Reiss), The Whale – in Search of the Giants of the Sea (Philip Hoare), and Giant Pandas – Biology and Conservation (collection edited by Donald Lindburgh and Karen Baragona). I just finished reading the dolphin book, and I am very intrigued by the mirror test (a form of testing for an animal’s self awareness) when applied to  bottlenose dolphins. More soon. Update: post on Dolphin in the Mirror here