I think it's important to deal with the question of what happens to the fish that we are using for our experiments. I received a concerned question from one of my students about how the fish are treated and if they are let back into the waters when we are done. This is definitely something worth talking about in more depth.
The blood samples are put in a centrifuge to separate out the plasma so that the hematocrit (% blood volume occupied by red blood cells) can be measured. Notice the heavier components, the red blood cells, are on the bottom and the clear plasma is on the top. For the coriiceps the hematocrit is around 35%. Do you know what it is for humans? What percentage of the icefishes' blood is occupied by red blood cells?
There is really no easy way to say it - these experiments will be terminal for all of the fish involved. In other words, none of them will survive or be set back into the ocean. We will be examining many tissue samples of these fish - blood, heart, brain, skeletal muscle, and liver as we go along. No part of the fish goes to waste and what can be learned from each individual is maximized in an effort to use fewer animals.
This is some heart muscle from a Notothenia coriiceps. The tissue is put in a device called a freeze clamp which has been sitting in liquid nitrogen so it is very cold. Then the tissue is flattened, wrapped in foil and placed into some liquid nitrogen. It can be carefully examined at a later date.
Your first reaction might be to think that this is mean. That is certainly understandable. But stop and think for a moment of all the times that you have taken medicine when you were sick or some of the necessities, inventions and knowledge that are an integral part of our lives and that we take for granted. Many of these were products of animal experimentation, including human tests. This has been a fundamental part of human progress. It has extended our lifespan. It has made the quality of our lives better. It has advanced our understanding and depth of scientific knowledge qualitatively. Though doctors still take the Hippocratic oath, we have come a long way from the four humors - black bile, yellow bile, phlegm, and blood.
IACUC
The advancement of science is dependent upon a certain percentage of loss of life of the animals we experiment on. The real issue at hand is ensuring that the experimentation is done in the most ethical and humane way and without gratuitous harm, pain, or needless experimentation. The Institutional Animal Care and Use Committee (IACUC) has set up strict guidelines and protocol (I know my students know this term! Right?) to follow when conducting research, research training, teaching and biological testing involving live vertebrate animals. In fact, I had to pass some IACUC tests to be able to take part in this research with the team. Dr. O'Brien and Dr. Crockett, in order to be funded for their research, have to submit reports detailing exactly how they will catch the fish, what specific procedures and tests will be done, how the animals will be anesthetized and euthanized. These very long, detailed forms require information about how many animals will be used; has anyone already done the experiment or something similar to the one being proposed; are they using the most recent and relevant techniques to carry out the experiment. The scientists must justify why the experiment cannot be performed on non-living animals. They want to know it all. A panel of scientists, a veterinarian, and someone from the community review the application and frequently come back to the science team with more questions before it is approved, if it is approved.
When performing surgery on the fish, it is kept alive by keeping a steady flow of water crossing over its gills. You can see those tubes inserted into this N. coriiceps' gill slits. The fish is anesthetized and does not feel this.
Scientific Advances from Animal Testing
There are people who feel that no animal testing should ever happen. To those people I ask 'Have you ever taken medicine?' 'Do you object to living longer, healthier lives than our ancestors?' 'Do you take advantage or engage in anything that has involved animal testing?' Examples? Vaccines against polio, Hepatitis B, and other life threatening diseases, the painkillers and Novocain you get at the dentist or in surgery, safe food additives, safe components and chemicals in cell phones, computers and other common products. And don't forget the advancements in veterinary science which helps animals. Are you or are they prepared to give these things up or to stop progress in organ transplants, pacemakers and other medical breakthroughs? That's the trade off. Again, the answer is not to ban the use of animals, but to do it in the most humane and responsible manner.
Dr. Kristin O'Brien takes a blood sample from an anesthetized fish.
So, I will talk about some of this as we continue our work down here in Antarctica. I will tell you about some of the things we hope to learn from these fish and some of the things that these fish have taught us already. And you can be part of this journey in advancing our understanding of life and science.
Kristin and Devin are reviving the N. coriiceps after surgery. The fish is put back into the water and a force of water is sent over its gills until the fish regains consciousness. You'll be happy to know this patient recovered successfully and was swimming around after being revived from surgery.