Unique Cages for Unique Pets
Posts tagged Iguanas
Iguana Metabolic Bone Disease
Apr 30th
Please check out the rest of NSHP’s website here.
Introduction
The most common reptile brought to our hospital is the green iguana. The primary reason owners bring in their ill green iguana’s is because they have developed a disease called metabolic bone disease (MBD), also known as nutritional secondary hyperparathyroidism (NSHP). The cause of this disease is poor husbandry, especially an inadequate diet. Unfortunately, the literature abounds with erroneous information on the precise needs of these creatures. This outdated an incorrect information continues to be propagated by individuals and organizations with good intentions but limited knowledge.
Iguanas are not the only reptile that encounters this problem. We find it in many types of lizards, turtles, and tortoises. It does not occur in carnivorous reptiles like snakes and monitor lizards very often because the whole prey they consume provides a proper diet.
We have a short Quicktime movie on an Iguana with twitching muscles. You need Quicktime from www.apple.com to view it.
Cause
This disease has many factors that work together in causing this condition. The primary reason iguanas develop this disease is due to a diet too low in calcium. More specifically, the ratio of calcium to phosphorous (usually the phosphorous is too high) in their diets is inadequate to promote growth and sustain normal physiological functions. As a result, they become very ill, and can even succumb to the disease.
Other factors that exacerbate the poor diet problem are common in most households that have iguanas. Inadequate exposure to direct sunlight (not through glass), not keeping the humidity at 90% and not keeping the temperature at 90 degrees F all add to the problem:
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Sunlight of a specific ultraviolet frequency is needed to produce vitamin D3 by the iguana’s skin. This vitamin is needed for the absorption and utilization of calcium in the diet. No matter how much calcium there is in the diet, without this vitamin the calcium would not be be absorbed or utilized . This is why milk that we drink is fortified with vitamin D. Black Lights and other artificial ultraviolet lights are helpful, but they can not replace sunshine.
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In order to maintain normal bodily functions (ability to digest food, fight infections, etc.) an iguana needs to maintain a high body temperature. Since they are reptiles, they maintain this temperature by absorbing the heat from their environment. They can not produce enough internal body heat like birds and mammals can when placed in a cold environment. also, the precursor to vitamin D needs to be at the proper temperature to be converted to the active form of the vitamin.
In the semi arid environment in some parts of the country, or the heat needed to warm homes in the winter, many iguanas live in a perpetual state of dehydration. This dramatically interferes with their physiology and predisposes them to many problems.
This is a typical Iguana cage that is inadequate. There is no branch with leaves to bask on, no access to any sun, let alone through the glass, and inadequate humidity. The bowl of water does not give enough moisture, and the heat lamp that is present in the corner does not supply proper ambient heat. Putting dirt in the bottom of the cage is a good idea.
Symptoms
Iguanas with this disease have many problems. The bones might be swollen, soft, or even fractured. In severe cases the blood calcium level becomes so low that tremors occur. The jaw might be swollen (called lumpy jaw by some people) because nature is trying to bring in supporting tissue to make up for the lack of strength to the bones of the jaw. The same thing happens to the bones of the legs, and when the problem is severe enough, or has gone on long enough, the bones of the arms and legs can fracture (called a pathologic fracture) all by themselves. Some of these iguanas will be unable to walk properly due to spinal cord damage, and many of them will be more susceptible to common infections because they are too weak to develop a proper immune response. As the bones of the jaw become weaker it becomes impossible to eat, further exacerbating the problem. They may have distended abdomens and bones leading their owners to the erroneous conclusion that their pet is fat and sassy, and receiving an adequate diet. Growing iguanas and females laying eggs have a greater need for calcium and might me more prone to this problem. Females with eggs might not have the strength to lay them, and sometimes even require surgery if they become egg bound.
Lumpy jaw occurs when the body brings fibrous tissue to the area to stabilize the weak bones. A lump at the jaw can also be caused by an abscess.
The fold of skin on the side of this iguana is evidence of dehydration.
This Iguana has such a low calcium level that the muscles are twitching. Double click the movie once it downloads and you can see the arm muscles and hands twitching. This is called tetany, and is a serious sign. The two most common causes of tetany in an Iguana are MBD and Kidney failure.
Diagnosis
A diagnosis of NSHP is made based on history, physical exam findings, and radiography. The history might indicate a diet of iceberg lettuce, dog or cat food, or packaged iguana meal. Swelling of the jaw and legs, low body weight, weakness, dehydration, poor appetite, and lethargy all might be noted on physical exam. X-rays are very diagnostic. Even though this is a problem of low calcium level, blood samples show normal calcium levels commonly.
This is the femur (thigh) bone of a healthy iguana. Compare it to the diseased one below.
This is the thinning (arrow) that occurs in this disease. In addition to poor bone strength, this iguana has an infection.
This iguana has a severe form of the disease. The spine is deformed which has interfered with the nervous system, so it is unable to walk or eat well. This creature is gravely ill. To let a creature deteriorate to this point is a crime.
An x-ray reveals the extent of the curvature problem to the spine.
Treatment
Iguanas that are diagnosed with NSHP are usually very ill and often need to be hospitalized. During hospitalization they are given fluids to correct dehydration, a special liquid diet, injections of vitamin D3, injections of calcium, oral calcium, and antibiotics if they have an infection. Those that have pathologic fractures are splinted.
After they are stabilized in the hospital they are sent home with calcium supplements, antibiotics if needed, and their dietary deficiency is corrected. They need to return weekly for at least several weeks for vitamin D3 injections and calcitonin injections.
A typical splint applied when both rear legs have pathological fractures.
An x-ray of this splint shows the padded paper clips that are used for support.
This different case was referred to us. The splints on these front legs are inadequate, as evidenced by the displacement of the fractured ends.
We performed surgery in order to correct this problem. These pins will be removed in 1-2 months.
This disease occurs in other lizards, like this young chameleon with numerous pathological fractures. There are differences in why this species gets this problem as opposed to the green iguana, but the main problem of inadequate husbandry stays consistent.
This little guy has fractures on all 4 legs due to inadequate husbandry.
In some cases the bones that allow the tongue to move normally are permanently injured and the tongue is rendered useless.
This disease also occurs in tortoises.The shell is soft due to inadequate nutrition.
Prevention
It must be fully understood that iguanas are ectothermic animals. This means they are highly dependent on their environment for their normal physiological functions, much more so than birds and mammals. They come from Central america where the temperature and humidity are consistent- 90% humidity and 90 degrees F. In addition, they bask in the direct sun many hours each day. If these conditions can not be replicated then these animals should not be kept in captivity. Ignorance of their needs is no excuse.
Their diet should consist heavily of dark green leafy vegetables in order to have the proper ratio of calcium to phosphorous. Contrary to what you may read elsewhere, these animals are not omnivores, they are strictly vegetarians, even when they are young. Therefore, high protein diets (dog food, cat food, protein supplements) are not to be fed to them. These high protein diets will cause them to grow bigger and faster, but will also cause their kidneys to fail. Vitamin supplements that contain calcium should be given weekly.
The following list describes would should and should not be fed. A combination of several items from the “Should Be Fed List” need to be fed, not just one or two items. For small iguana’s it is helpful to dice up your vegetables into very small pieces so that they don’t eat only a few items.
Foods That Should Be Fed
Collared GreensMustard GreensGreen LeafRed LeafButter leafDandelion GreensMango and PapayaBroccoliNon toxic flowers
Foods That Should Not Be Fed
Dog FoodCat FoodRodentsEggsIceberg LettucePizzaMeatInsects
Prognosis
This disease is correctable and preventable. If a pet iguana is brought to us in an advanced state of the disease then the prognosis is not good. Otherwise, we are able to return a large percent of them to relative normalcy if our full treatment regimen is followed. After the immediate problem is corrected it is mandatory to provide the optimum environment for their proper quality of life.
Building vs Buying
Apr 20th
More info from the Green Iguana Society. This was written in regards to iguana habitats but it holds true for cages in general. Good insights into the Building verses Buying debate. Check out the rest of their site here Green Iguana Society .
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| If you are like most people, chances are your iguana needs a better habitat. Most likely, your iguana needs a habitat that is much larger than the one it currently has, and now you must decide the best way to get it what it needs. On this page, we’ll be discussing the pros and cons of building your own or buying a complete habitat. You basically have three choices: buy one that is already made, have someone you know build one, or build it yourself. First of all, make sure you learn all you can about what type of habitat your iguana needs. Once you learn what your iguana needs, buying or building a habitat will be easier, and you won’t end up with a habitat that you’ll need to replace later on. Most iguana owners end up going through several different habitats because they are still learning, and they discover later on that they should have done something different. Whether you’re building your own or buying a custom built habitat, learn all you can before you decide, and try to do it right the first time.
Buying a custom habitat – Although it may sound like the best way to go, buying a ready made cage or habitat usually isn’t the best way to go, unless you have a lot of money. Even then, you can end up with a habitat that isn’t the best for your iguana. There are many custom habitats and cages available, and most generally, they are very expensive and often times far too small for an adult iguana. There are only a few places that sell habitats for iguanas that are of suitable size. If you can afford one of these and do not want to venture into building your own, then by all means, buy one, but make sure it’s of suitable size and functionality for your iguana. Your iguana will get LARGE and it will definitely need a large habitat, unless of course you plan on allowing your iguana to be a free roamer. If you are allowing your iguana to be a free roamer, it can also be a good idea to have a habitat of some sort for your iguana to retreat to, if needed. If this is the case, you may be able to get away with providing a somewhat smaller habitat, but it still needs to be quite large. For more information on free roaming and setting up your home for a free roaming iguana, please visit our Freedom & Free Roaming section. If you do decide to look into buying a custom-made enclosure, the web sites listed below may be useful:
Custom Wood Reptile Cages – http://customwoodreptilecages.com Cages By Design – http://www.cagesbydesign.com Keith van Zile: Lizard Cages.com – http://www.lizardcages.com J.Worlds Unique Reptile and Rainforest Enclosures – http://www.jworlds.net/ (WAY expensive, but really cool) Size is critical – Most importantly, size will be the most important factor when choosing a habitat. Unfortunately, there are many types of cages and enclosures that are sold as “iguana cages” and chances are, they are far too small to be a permanent home for your iguana. Not only are these cages too small for an adult iguana, they are usually quite affordable. This is yet another form of misinformation about iguana care that leads to many iguanas being kept in inadequate habitats, which will most definitely lead to unhealthy and unhappy iguanas. You may be able to “get by” with a smaller cage, but ultimately, the health and happiness of the iguana will suffer. An iguana in a habitat that is too small will be stressed, which can lead to restlessness, nose rubbing and other injuries that are caused by the iguana trying to get out of a small enclosure. You can also get by with a smaller habitat while the iguana is a juvenile and still growing. Going through several habitats throughout the life of the iguana is normal for most iguana owners. If you do it right the first time and buy or build a habitat that is large enough for an adult iguana, you may spend more money now, but the habitat should last your iguana’s lifetime. Cost of a good habitat – It will cost a good amount of money for a suitable habitat. Going through several habitats, either built or bought, will become even more expensive than building or buying a LARGE habitat as early as possible. If you’re buying a habitat, be prepared to spend a great deal of money on one that is large enough for an adult iguana. You’ll probably have a very hard time even finding one large enough, and if you do find one that’s big enough, it will be very expensive. Also, most habitats that you buy do not come with light fixtures, switches, dimmers, and other accessories you may need. If you can’t afford to buy a habitat that is large enough for your iguana, then we definitely recommend that you build your own. Building your own can be much more affordable, but it will still be expensive. Depending on the materials you use, you’ll probably end up spending at least $150 (U.S.) building your own. Chances are, you’ll spend more than that, but it will usually cost much less than a pre-built one of the same size and quality. Building your own habitat – The best part of building your own habitat is that not only will your iguana have what it needs, you can build it exactly how you want it. Once again, you can usually build your own for much less than a pre-built one. Of course, you can also build one that costs much more, but chances are, it will be very nice and well worth the money in the long run. With building your own, you can also make use of exactly the amount of space in your home you’d like to give to your iguana. Many pre-built habitats come in a variety of sizes and colors, but if you build your own, you can make it exactly the size you want, as well as build it to become a decorative and attractive addition to your home. Do tools intimidate you? If you have absolutely no experience with tools, carpentry, electrical work, and building things, then buying a habitat may be the way to go. You may also want to try to get the help of a friend who does have more experience. More times than not, iguana owners end up learning about iguanas as well as carpentry and electrical work. Many iguana owners who had no experience with carpentry are now seasoned pros after building their own habitat. If you do have little or no experience with building things, you will also have the added expense and worry of having or buying the tools you will need to build a habitat. If you have few or no tools, you’ll either need to find a friend that will loan you some basic tools or you’ll have to buy your own. You can literally spend a fortune on high quality tools, but you can also buy inexpensive hand tools, especially if you don’t plan on using them for anything else. Conclusion – If you are planning on getting a new habitat for your iguana, then this is going to be a big decision to make…to buy or build. We would like to suggest that building your own is the best way to go. If you have experience with carpentry, electrical work and building things, then this should be a very easy decision. If you have little or no experience, we suggest that you find a friend that does have some experience and tools to help you. Whatever you decide, we can not stress it enough…. learn all you can about what your iguana needs, make sure you provide a LARGE habitat, and if at all possible, try to do it right the first time so you don’t end up building or buying several habitats throughout the life of your iguana. For more information and what kind of work is involved with building your own habitat, please visit our Planning & Construction page. |
Iguana Habitat
Apr 20th
Info from the Green Iguana Society. We’ve never dealt with them personally but they seem to have some very accurate and reliable information on their site including a list of iguanas available for adoption. Definitely check them out here Green Iguana Society .
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Heat/Lighting – Iguanas need an enclosure or habitat that is kept very warm. Temperatures under basking lights should be in the low to middle 90’s (Fahrenheit), and the ambient air temperature surrounding your iguana should be no lower than 80ºF. Within the cage, a range of temperatures should be provided so that your iguana can regulate its body temperature by moving back and forth between cooler and warmer areas. Daytime heat is best provided with incandescent light bulbs.
Hot rocks are not recommended for iguanas! Not only are hot rocks inadequate in providing heat, but they are dangerous. There have been numerous cases of iguanas obtaining serious burns from hot rocks. Heat and light should come from above, since in the wild iguanas bask in the sunlight. Ordinary incandescent light bulbs work great to provide both heat and light. You do not need to purchase expensive “basking bulbs” from the pet store. These are no different than ordinary bulbs. What wattage of bulbs you will need depends upon the ambient air temperature of the room and the size of the enclosure or basking area. Do not guess when it comes to temperature! It is imperative that you install a few good, reliable thermometers at various places in the enclosure to give you an accurate temperature readout. You can also hook up dimmer switches to your lights, which will allow for minute temperature adjustment. Hooded clamp fixtures work well for basking lights, come in a variety of sizes and can be positioned in various ways within an enclosure. Be sure to use fixtures that are designed to accommodate the bulb wattage you are using. If you are using high wattage bulbs (150-250W), you must use a fixture with a ceramic socket to prevent fire hazard. Be sure to place the fixtures in such a position that your iguana cannot climb on or touch them. If you place the fixtures inside the enclosure, it is a good idea to add a wire “bulb guard”, such as you see in the photo below, to prevent your iguana from coming into direct contact with hot bulbs. Bulb guards can be made from hardware cloth or other safe types of wire. If you have a smaller iguana that is likely to climb up on and/or cling to the light fixtures, consider placing the fixtures outside of the enclosure. |
 This simple bulb guard was made from a small piece of hardware cloth, which is held in place by the simple guard that came with the fixture. The edges of the wire have been bent under so that no sharp edges are exposed. |
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Nighttime heat – Like all other animals, iguanas must have a day/night cycle. We recommend a 12:12 or a 13:11 cycle. This means that you must shut your iguana’s lights off at night for 12 or 13 hours, or better yet, have them on a timer that turns them off at night and on again in the morning so you do not have to remember to do it. This allows the iguana to regulate behaviors and rest peacefully when necessary. Not providing a day/night light cycle can stress an iguana, causing behavioral changes such as feeding, pooping and unnecessary aggression. Iguanas can and should have cooler temperatures at night, but they still need ambient air temperatures to fall no lower than 75-78ºF. How then, do you provide heat at night, if you use light bulbs to heat the enclosure? There are a few methods of providing nighttime heat. One of the best is to use Ceramic Heat Emitters (CHEs), which screw into an incandescent light fixture and give off only heat, not light. These are available in different wattages. It is possible to have a set up where the lights come on in the morning and turn off at night, and the CHEs come on at night and turn off in the morning. Another possibility is to use a low wattage CHE 24 hours a day in addition to the daytime lights. Since iguanas can and should have cooler temperatures at night, a CHE of the appropriate wattage should provide adequate nighttime warmth.
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A word of caution about CHEs – they get very hot and can be fire hazards and/or dangerous to your iguana if not used correctly. Be sure to use them only in fixtures with porcelain or ceramic sockets, and keep them away from dry wood or fabrics that are flammable. Be sure to place them in a way that will not allow your iguana to come in contact with them, because their surfaces get very hot and can cause severe burns. Use only the appropriate extension cords that can handle the amount of wattage you plan to plug into them. A CHE can be an efficient and safe source of heat for your iguana, but only if you use them properly. Be sure to read all of the directions and cautionary statements supplied by the manufacturer. Be safe, use your common sense, and above all, be careful – not only with CHEs, but with other heating and lighting devices as well.
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| Internally-ballasted MV Bulbs: Pros
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Internally-ballasted MV Bulbs: Cons
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| Heat & UVB in one fixture – convenient.
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A bit more expensive than traditional tubes. Cost is usually around $45 each.
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| Give off higher levels of UVB than tubes.
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Can produce too much heat when used in smaller enclosures – especially the spot bulbs.
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| May enhance your iguana’s green coloring and appetite (this is based solely on anecdotal evidence).
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Have a high burn-out rate. The bulbs are fragile and break if jostled. Bulbs are guaranteed, but returning broken bulbs can be a hassle.
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| UVB travels further from the bulb, so they work better for larger enclosures and free-roaming iguanas.
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The spot bulbs give off higher levels of UVB that travels a further distance, but the area covered by the bulb is less. Iguanas must stay directly under the bulbs. The flood bulbs cover a greater area.
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| Externally-ballasted MV Bulbs: Pros
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Externally-ballasted MV Bulbs: Cons
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| Longer-lasting with a lower failure rate than internally-ballasted MV bulbs.
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More expensive than traditional tubes and internally-ballasted MV bulbs. Cost is usually around $75 each.
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| Give off higher levels of UVB than tubes.
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Do not give off heat. A separate heat source is required.
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| Can be used in smaller enclosures due to low heat output.
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Not as widely available or as easy to find at this time as traditional tubes and internally-ballasted MV bulbs.
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| Traditional Fluorescent Tubes: Pros
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Traditional Fluorescent Tubes: Cons
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| A bit cheaper per bulb than MV bulbs.
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Should be doubled-up for best results, thus bringing cost closer to that of interally-ballasted MV bulbs. Two tubes will usually cost around $30-$45.
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| Can be used in smaller enclosures where an internally-ballasted MV bulb may produce too much heat.
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Produce much less UVB than MV bulbs. Plus, because fluorescent tubes do not produce heat, additional heat bulbs are necessary.
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| Have a lower burn-out rate than internally-ballasted MV bulbs.
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Do not work well in cheap fluorescent fixtures. High-end fixtures are necessary for maximum UVB output.
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| Come in different lengths to fit different enclosures.
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The UVB does not travel far; thus it is necessary that the bulb is positioned no more than 12″-15″ from the iguana.
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This photo shows one way to increase the humidity in an enclosure. An ordinary drier duct is attached over the outlet of a cool-mist humidifier with duct tape, and the mist from the humidifier then enters directly into the enclosure through the duct. This simple set-up raises the humidity in the enclosure by as much as 20%. |
| Conclusion – There are a variety of enclosure designs that will be equally successful at providing your iguana with what it needs – proper heating, lighting, and humidity. What materials, design and heating/lighting devices you choose to use will depend upon the size of the enclosure or habitat, the placement of the enclosure, the surrounding room temperatures, and so on. For ideas on how to decide whether to build or buy, how to go about choosing the best building materials, and how to actually put it all together, visit our Building vs. Buying page, and the Planning and Construction page. If you have more than one iguana, visit our Multiple Iguanas page for a discussion on the pros and cons of housing two or more iguanas together. Thinking about building an outdoor cage? Check out the Outdoor Sunning Cages page. |
Iguana Facts
Apr 20th
Physical Appearance: Full-grown green iguanas are usually between four and six feet, although they have been known to grow up to seven feet long. This includes the tail, however, which can make up about half the body length and, in addition to its green color, has black stripes. Green iguanas, not surprisingly, are green in color, but can be found in many different shade ranging from bright green, to a dull, grayish-green. Their skin is rough, with a set of pointy scales along the iguana’s back. Green iguanas have long fingers and claws to help them climb and grasp.
Geographic Range: The green iguana is found over a large geographic area, from Mexico to southern Brazil and Paraguay, as well as on the Caribbean Islands.
Adaptations: Besides the long fingers and claws mentioned above, green iguanas have many excellent interesting adaptations. Green iguanas have good senses of hearing and smell, and superb vision. Their long tail is also quite sharp, and is snapped in the air as a defense mechanism. The tail can also break off if caught by a predator, but grows back without permanant damage. Green iguana skin is very water resistant, and tough to avoid cuts and scratches. The coloring of the skin helps camoulflage the green iguana, which means that they blend in easily to their surroundings to remain undetected by predators. If they are etected however, and need to escape quickly, these iguanas can dive from trees into water, and swim well. Green iguanas are quite sturdy– they can fall 40-50 feet to the ground without getting hurt! Male green iguanas have a special flap of skin called the dewlap. Male iguanas can raise their dewlap to appear bigger than they really are, either to intimidate predators, or to impressive females. Both male and female green iguanas can store fat under their jaws and in their necks for times when there is not much food available.
Habitat: Iguanas live in tropical rainforest areas, generally in lower altitudes in areas near water sources, such as rivers or streams. They spend most of their time high in the forest canopy, about 40-50 feet above the ground.
Behaviour: Iguanas are diurnal, meaning that they are awake during the day. They are also cold-blooded, which means they do not produce their own body heat. In other words, if it is cold, the iguana is cold too. So to stay warm, green iguanas bask in the sun, lying on warm rocks as they soak up the sun’s heat.
Reproductive Cycle and Family Habits: Green iguanas tend to live alone, but may be seen in groups occasionally in good sunny basking spots. Iguanas lay many eggs at a time (about 50), in holes inthe ground called burrows. They also dig pretend burrows to confuse any animals that may be looking for eggs to eat. After female iguanas lay the eggs, they leave them and do not return. When iguana babies hatch, they grow up without care from their parents. Green iguanas lay many eggs, but only 3-10 babies actually survive to be adults. It takes green iguana eggs about 8-10 weeks to hatch, then takes baby iguanas about 2 years to become mature adults.
Diet: Green iguanas are omnivorous, so they eat both plants and meat. They tend to eat mostly plants, though, especially leaves and fruits. Sometimes green iguanas (especially young ones) will eat eggs, insects, and small vertebrates.
Threats to Survival: Like many trpoical species, the green iguana is also threatened by habitat destruction. The green iguana is also a victim of the pet industry. Many people in the United States and elsewhere want a green iguana for a pet, so there is a big demand for their capture. Although many pet iguanas are now being raised on iguana farms, capture from the wild has lowered their numbers. In addition, some local populations of South America hunt the green iguana for food.
Conservation Efforts: Laws have been made to protect green iguanas from over-hunting and the pet-trade. Unfortunately, these laws are not enforced very well. Many people are trying to develop protected areas for the iguanas, and to educate local populations about the importance of conservation. Some of these educational programs help local populations find new ways of using the land, without permanantly destroying it. For example, for people who want to continue to eat the green iguana, programs are being developed to raise these animals for food, instead of hunting wild ones. Tony Garel, at the Belize Zoo and Tropical Education Center, is woking on one such project to conserve the iguanas and educate local communities Tony has used captive breeding techniques to increase green iguana populations, and has released some of these iguanas into the wild.
Iguana Wikipedia
Apr 20th
See the original Wikipedia article here
Iguana is a genus of lizard native to tropical areas of Central and South America and the Caribbean. The genus was first described by Austrian naturalist Josephus Nicolaus Laurenti in his book Specimen Medicum, Exhibens Synopsin Reptilium Emendatam cum Experimentis circa Venena in 1768. The genus Iguana includes two species: the Green Iguana, which is widespread throughout its range and a popular pet, and the Lesser Antillean Iguana, which is endemic to the Lesser Antilles and endangered due to habitat destruction.
The word “Iguana” is derived from a Spanish form of the original Taino name for the species “Iwana”.[1]
[edit] Anatomy and physiology
The two species of lizard within the genus Iguana possess a dewlap, a row of spines running down their back to their tail, and a third “eye” on their head. This eye is known as the parietal eye, visible as a pale scale on the top of the head. Behind their neck are small scales which resemble spikes, known as tuberculate scales. These scales may be a variety of colors and are not always visible from close distances. They have a large round scale on their cheek known as a subtympanic shield.
Iguanas have excellent vision and are able to see shapes, shadows, colors and movement at long distances. Iguanas use their eyes to navigate through crowded forests, as well as for finding food. They use visual signals to communicate with other members of the same species.
They respond to visual stimulus of colors such as orange, yellow, pink, and in rare cases blue as food substances.
An iguana’s ear is known as the tympanum. It is the iguana’s ear drum, and is located right above the subtympanic shield and behind the eye. Iguanas are often hard to spot, as they tend to blend into their surroundings. The color green helps as a mode of hiding from larger predators.
The male iguanas have, as well as other male members of the order Squamata, two hemipenes.