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Fifteen Animals You Didn't Know were used in Laboratory Research
Jellyfish are one of the more unusual common laboratory animals, carrying this distinction in more ways than one. Jellyfish are hard to keep in captivity and even harder to breed. However we still use them for all sorts of research. Currently we're studying their mesmerizing movement in order to create robots that can mimic them. There are a lot of other experiments done with whole jellyfish - figuring out how they sting, how they move, how they respond to light, but most commonly jellyfish are used for their ability to glow. Osamu Shimomura was the first to identify which proteins in them made them glow in 1962. In 1992 these proteins were sequenced and the specific genes involved were isolated. Not long after we started infusing non-jellyfish animals with these genes. We've probably all seen photos of glowing cats, bunnies, fish, but we might not understand what the point is. Basically it makes it easier to see the progress of disease. For instance if you are studying the hearts of glass fish you can infuse this gene into them and only their hearts will glow. This makes it easier to see physical changes in said heart.
Axolotls can be found with fairly high frequency in pet stores and in the hands of private breeders but this isn't where they started. In fact their first use was as a laboratory animal. They were seen as very beneficial to the laboratory setting because they were an easy to breed amphibian that spends their entire life in the water. This is important because it's an animal that has evolved to keep many of its juvenile features - one of which is the ability to regenerate damaged or missing limbs. To understand this we must understand that normal amphibians, like frogs, start out as something, a tadpole in this case, that looks nothing like a mature frog. As it grows it will absorb the nutrients in its long fish-like tail and start to grow legs and more frog-like features. If at some point during this process the frog loses a leg, say to a hungry fish, then it can grow it back, but only until it is of a certain age. In axolotls, salamanders, and newts, this ability remains with them for their whole life as they never grow to the point they can survive on land like a frog. This makes them ideal for studying limb regeneration, cell division, and any medical curiosity that might come from those fields. If we can figure out how they do this we might be able to allow humans to have the same almost magical power. We'd put the prosthetic limb industry out of business overnight!
Degus are a small New World rodent that made it into the pet trade in the US probably in the 1990s. They're related to chinchillas and look like a mix between a chinchilla and a gerbil. They're neat little highly vocal creatures that started out in our laboratories. We've been studying them for decades because they are naturally prone to cataracts and all degus have a form of sugar intolerance that is basically the same thing as diabetes in humans. This condition does not cause them any harm in the wild as they don't eat sugary foods but in captivity I can't say the same. We use them for cataract studies as well as diabetes research (because they can and will eat sugar when it's supplied to them.) They make good laboratory animals not only because of these two special conditions but because they are fairly easy to breed, can be contained in relatively small areas, and can be kept successfully in groups.
4) Fruit Flies
Fruit flies have been a much beloved laboratory animal for over 100 years. They are very useful because you can keep thousands, even millions, of them in a very confined space and even better still they reproduce very quickly. A whole generation will be born, live, breed, and die, all within two weeks. This makes breeding for abnormalities intensely easy if you spot it on time. Another reason fruit flies are used is because they share 75% of their DNA with us including many genes that cause the same diseases they do in humans. So basically they are used to research genetic diseases. The genes of fruit fly larvae are also physically enormous - which makes looking at them under a microscope and finding abnormalities that much easier. There are hundreds of labs out there dedicated to studying only the lowly fruit fly.
5) Zebra Fish
Zebra danios have been a very common fish sold in the pet trade for decades and perhaps for even longer they have inhabited our labs. In fact they have been there since the 1930s, so long that they have established patterns of true domestication (they're more docile than their wild counterparts and have far more offspring.) Even more fascinating they were the first vertebrate animals to be cloned. They are also the fish that are being used to create "Glofish" for the pet trade. These fish were all born in labs - engineered to display at least one glowing gene, usually taken from a jellyfish. But what are they really used for in studies? A lot! With the help of the jellyfish genes they have been used to study everything from inflammation to cardiovascular diseases to muscular and skeletal diseases, cancer, nervous system diseases, you name it! These fish are hardy, breed easily, live well in large groups, and have offspring who can be studied very easily in the embryonic stages. In fact it's routine to take zebra fish embryos from the egg and raise them in a petri dish where they can be scrutinized under the microscope. Believe it or not you probably owe a lot to these humble fish. They have been crucial in many studies and currently are the animal of choice in hundreds of labs. To the right is a photo of a zebra danio bred in it's natural state and below is a school of jellyfish gene infused "Glofish" zebras.
6) Hammerhead Sharks
Did you know hammerhead sharks are the only other creatures besides humans that tan when exposed to the sun? This fact becomes all the more remarkable when you realize these animals are extremely resilient to cancer. No matter how much sun they're exposed to none have ever shown up with skin cancer. In an attempt to figure out why this is (and hopefully develop resistance to skin cancer in humans) we have set up outdoor labs to study these animals. The problem is hammerheads are large and need a lot of space. They also are hard to keep in captivity. So we have come up with a compromise. We collect babies, no more than a couple feet long, who have a habit of schooling to protect themselves from predators, and keep them in shallow sectioned off sections of natural ocean. The shallow depth of the water ensures that the sharks get plenty of sun and the fact it's outside in the actual ocean alleviates the need for a very expensive large set up of aquariums or man-made pools and besides this the sharks do better too. The normal coloration of these animals is gray but when they are exposed to large amounts of sun they will actually turn darker and darker, some even turning black. Conversely animals kept in dark conditions can go in the opposite direction and turn and almost albino white. When these studies are completed or the animals grow too big to keep they are allowed out of their pens to swim off into the ocean at large. As far as laboratory animals go these sharks have it pretty good!
Octopi have a lot going against them as far as being a research animal goes. they are ill-suited to the typical laboratory setting for a few key reasons. For one they do not get along with other octopi, they require quite a big of space being fairly large animals, and the females only breed once before dying. Did I mention they're escape artists? A one pound octopus can life a forty pound tank lid and can and will happily crawl out and explore the land. This is why they're very rarely seen in the saltwater hobby. When you do see them you hear lots of horror stories like, "Yeah, I tried keeping an octopus once - had him for two weeks before he got out of the tank and tangoed with the dog. He didn't make it."
With that all being said octopi are very suited for some laboratory studies. Along with cuttlefish and squid they are considered the smartest invertebrates in the ocean and are very useful to do intelligence studies, memory tests, as well as behavioral observations. In addition to this octopi can change color in an instant and even can appear to change in texture. This unique ability is also studied in great detail. Some laboratories keep smaller species of octopi or babies while others study octopi in outdoor corrals much like the hammerhead sharks we talked about before. Octopi are territorial and tend to return to the same cave or rock crevice after hunting so they are easy to identify as individuals and find when needed which makes them easier to work with than cuttlefish or squid.
Frogs have been used in laboratory research for a very long time because of the ease in which some varieties breed in captivity as well as their exceptionally sensitive reactions to changes in their environment. You can usually keep them in groups in well stocked terrariums and for the most part these frogs are usually kept in pristine habitats. They're mainly used to test the effect of toxins and pollutants in the environment because they are an "indicator species" - meaning they are very sensitive to these changes and will often alert hardier species, like us, of impending danger if those pollutants start rising. Occasionally frogs are also used to study limb regeneration as well.
Finches, especially zebra finches, have long been used to study the dynamics of breeding behavior. These finches are generally kept in large flight cages with many other finches and they are watched to see which mate they chose. In one study researchers wanted to know how important symmetry was to females choosing a mate so they took all the male finches and gave them two leg bands, one on each leg. In half these finches they gave matching leg bands, in the other half they were given two different color leg bands. Sure enough females seemed to much prefer the males with matching leg bands! Other studies found that zebra finches aren't as monogamous as we once thought - with both males and females occasionally coupling with the finch next door when their bonded mate wasn't looking. Now we're studying them to find out why they might display this behavior at the risk of catching a social disease. Finches are also used in flight studies and other behavioral research. They're ideal birds to study because of their small size, rapid breeding, and ability to get along in large flocks.
Spiders are difficult animals to study. For one they are very difficult to breed. They are solitary animals that don't like the company of their own kind and when you introduce a male to a female's habitat more often then not you just end up with a dead male and a well fed female. Being this anti-social they also need their own habitats so despite their size they take up quite a bit of space. So why bother with them? Well all sorts of reasons but mostly for their webs. Many years ago, in 1948, NASA did a study to see what various drugs did to spiders who were making webs. They fed the spiders flies who had been dosed with various drugs - everything from caffeine to LSD. Each web was drastically different. For instance the caffeinated spiders showed frenzied and patternless webs while the ones given LSD seem to have gained acute OCD with their webs becoming intensely complicated with extremely even and perfect webs. Today we use spiders to study the silk they use for their webs. It is the world's strongest natural fiber, far stronger than any man-made fiber as well and we are trying to figure out how to produce it en masse to make bullet proof vests and high tension ropes for other usages (like tethering airplanes on aircraft carriers.) Currently we are trying to do this by inserting the web making gene into dairy goats whose milk provides the fiber needed. It's not nearly as effective as natural spider silk right now but with adjustments who knows! Maybe spider goats will be the answer.
Nematodes, also known as roundworms, are a type of parasitic worm that on any normal day you probably wouldn't want to have any interactions with... They're commonly found infecting dogs and cats and can and will hijack the human body, sometimes killing them when they go astray and wind up in your brain. It's rare, parasites generally don't want to kill the host they're feeding on, but sometimes it happens.. So what can these worms give us in a laboratory setting? Apparently a very long life. Researchers at the Buck Institute for Research on Aging have identified various proteins that have extended the life of these nasty little creatures to the equivalent of a person living to 400 or 500 years old. They hope that this new knowledge will help them combat Alzheimer's and other age related diseases.
13) Praying Mantis Shrimp
Praying mantis shrimp aren't praying mantises or shrimp. They're a creature unto their own, and although most people have never heard of one they are absolutely fascinating. They are currently being studied for two very special characteristics. For one they probably have the most sensitive eyesight of any creature on the planet. Humans can only see three colors - blue, red, and green. Any other colors we see are just combinations of two or three of those colors. Mantis shrimp on the other hand can see far more than three colors, they can see sixteen different ones and every color that comes from combining any of those! This might be able to account for the fact they are psychedelically colored. Another amazing feature of this animal is their ability to punch prey and predators trying to eat them. Yes, I did say punch. They do this with special appendages that look similar to claws. They can strike so fast and with such force that air bubbles are formed on the site of impact that are heated by the friction to temperatures hotter than the surface of the sun. Targets are hit with 1,500 newtons of force in three one thousands of a second. That's like being hit with 337 pounds in an event so fast your eyes won't even catch it. So much force is involved in this act that it has the same velocity as 22 caliber rifle and creates it's own flash of light. If we could figure out how these creatures are doing this the ramifications could be significant, especially in military technologies.
And just so you know praying mantis shrimp are not always the most cooperative of lab animals (or pets, as they're sometimes kept in the saltwater hobby.) Their keepers have affectionately named them "thumb splitters" because of their objection to being handled and their tendency to, well, hammer their keeper's thumbs.They'll kill anything they're housed with, including other mantis, and have a rather bad habit of clubbing and cracking the glass aquariums they're kept in. All and all they're.... difficult... but well worth a look!
14) Naked Mole Rats
Naked Mole Rats may not be winning any beauty pageants anytime soon but they have a series of unique characteristics that are making them popular in labs today. They've been popular zoo exibits for many years and are happy to be kept in colonies. They have held the public's fascination for not only being a contender for one of the world's ugliest animals but also for the fact they have a queen and are one of the very few mammals in the world that operate like an ant colony with one breeding female (the queen) and a bunch of workers tending to her needs and not breeding themselves. That social structure is worthy of study on its own but it's another strange fact that came to scientists attention recently. In over fifty years of being kept at zoos no one had reported any death from cancer, which is often common in small rodents. They were brought into the lab to study this and are currently giving new answers to possible preventatives this this disease as scientists have been unable to give them cancer. They seem to have preventative powers as well as cancer fighting powers when they are forced to contend with the disease. Time will tell if these strange little animals will save lives by telling us just how they do this.
15) Prairie Voles
Prairie Voles have been used for a series of behavioral studies because of their unique life style. They are one of an intensely few number of mammals that are truly monogamous. After choosing a mate they will stay with their partner for life, only choosing another if the first dies. This is very unusual among mammals and even more so among rodents. This has made them the darlings of relationship research. They've been observed, tempted, and tested for hormone levels trying to figure out why they are so loyal to one another. Currently the answer is believed to be in their oxytocin levels, a hormone that was once only thought to help mothers bond with their newborns now shows it has a much broader use as an aid with bonding with other individuals, specifically those we're romantically involved with. We would have never known this if not for the lowly lemming.