There is this one certain animal that I have done some work with that I think is absolutely amazing. It is called the planaria, and it is a free-living, freshwater flatwork. They are very small, and very simple, so you may be wondering why I take such an interest in them.
The reason is that they have the extraordinary power of regeneration. If you cut them in half, the head end grows a new tail, and the tail end grows a new head. It is pretty amazing. In fact, a fun thing to do with the little creatures is to slice them halfway down their body vertically, and then they grow two new heads on one body.
At this point you may be thinking that is is a extremely cruel practice; cutting things up for fun does not seem like a great idea. But planaria do not, basically, feel pain. They have a very simple structure, with a bundle of nerves in their head that could be called a brain. They have a ladder structure throughout their body to transport nutrients and waster, as well as to serve their reproductive purposes. Below, you can see a diagram of the normal planaria.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgewu98sJAK8Ggt9bY2StUtTzU7Uvlb2RN0PP90AsqCztZH3Jxzf5MyidnOeN9NzfB5ZJv9o6Zh-bjqajhcZACFzdxKSd-5Q8CqiL8RrW7EQypRwc011jKdh8QSDN-o17vhFMfc4os_7SI/s400/planaria2.gif)
The work that I have done with these animals is researching to discover if a certain type and color of light increases or decreases their regeneration rate. I found that LED light, in particular infrared LED light, increase their regeneration rate. This may not seem like a very important discovery, but infrared LEDs are currently being used to help heal wounds, and humans do not regenerate, but we do heal.
The interesting thing, though, is that even though this light makes the planaria regenerate faster, planaria do not like to be exposed to light. This got me thinking. The reason that planaria regenerate and do not heal is because regeneration is a slower, but healthier, process. Healing damages you, leaving scar tissue, and the reason we heal is to stop us from bleeding to much. Planaria do not bleed, so they take the healthier option: regeneration. Healing is basically just producing more cells to fix the wound. When humans have too much of an increased cell production rate, cancer develops. This could be the reason that planaria do not like light, and that constant light exposure causes the planaria to regenerate slower than just 6 hours a day.
What I found here, basically is that infrared light can be used to help healing. The planaria are evidence. But we have to be careful with the methods we are using now. For a long time we though that ultraviolet light was the only cancer causing light. Infrared light can cause cancer too, when it is used in too long of time periods.
Another interesting thing is that Infrared light travels easier through skin tissue that ultraviolet light does, as they are on different ends of the electromagnetic spectrum. This could be why ultraviolet light lead to skin cancer and infrared light may lead to cancers of the internal organs.
So this amazing little planaria is not only cool, but it can show us a lot of healing and cancer research. In addition, they are quite cheap. If you would like to play around with some of them, just let me know, and I can get them for you at a discounted rate. If not, you can order them at Carolina Biological Supply, and you will also need some X-Acto knives to cut them with. Have fun, and learn a lot from these flatworms!