Spiny -Tailed (Black) Iguana Care Sheet

Spiny -Tailed (Black) Iguana

Scientific Facts

Common Name:Spiny Tailed Iguana, black spiny-tailed iguana, black iguana or black ctenosaur
Scientific Name:Ctenosaura similis
Life Span:4.8 years
Size:1.3 meters in length
Habitat:Savanna or grassland, rainforests, forests, and scrub forests
Country of Origin:Found throughout Mexico, large areas located in Central America and islands near Panama

Physical Description

The spiny-tailed black iguana is a large, bulky iguana. Males of the species can reach up to 18 inches long, and the tail alone can be as long as its body. These iguanas are mostly black, but the dorsal areas may also have black bands on a gray background. Most spiny-tailed iguanas have black mottling along their backs.  

The color of these lizards may become lighter after they have absorbed sufficient sunlight with the yellow and orange marks seen very evident along the lizard’s sides. The adult male and female of the spiny-tailed iguana are dimorphic, which means you can easily distinguish the appearance of the males from the females.

Adult male spiny-tailed iguanas have developed dorsal crests as well as small dewlaps or folds of skin found along the neck. The dewlap can also extend to the throat, and usually, this is not inflated. Usually, a small bone is bowed to extend the dewlap when the lizard feels threatened or when it’s courting a female during the breeding season. There is only minimal difference in juvenile and adult members of the species, and this makes it difficult to determine the age of the iguana.  

These lizards come with ringed tails that have rows of sharp and curved spines. This is where the spiny-tailed iguana got its name. The spines along the back are short. Meanwhile, juvenile black spiny-tailed iguanas are usually tan in color, and then these change from tan to gray or black as these mature. 

The spiny-tailed iguana is a species of iguana native to Mexico as well as large areas of Central America and islands that are adjacent to Panama. In the wild, these lizards remain in areas where there are places to bask and areas to hide if the day becomes too cold. 

The spiny-tailed iguana loves to dig and is known to bask for a very long time in groups. You’ll find these in rocky and open slopes, large trees, and along the borders of rainforests. Generally, these lizards are found in arid and open areas. They don’t hide and are not afraid of people, which makes them an ideal pet lizard, according to some reptile lovers.  

Life Span 

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The Spiny -Tailed (Black) Iguana has three life stages, just like other iguana and lizard species:


It can take up to 4 months for iguana eggs to hatch. It can take up to a week before hatchlings climb out of their nests. Hatchlings are so tiny that one lizard can fit in the palm of one hand. Experts say that when an iguana has survived his first year of life, it’s certain that they can live for more than 60 years. This is because hatchlings are often prey to different predators like owls and hawks. 


During the juvenile stage, both male and female Spiny -Tailed (Black) Iguanas will grow at the same rate. Juveniles are usually tan in color and will slowly change to a grayish color (close to black) as these mature. At this time, juveniles can look for food and fend for themselves.  


Adult Spiny -Tailed (Black) Iguanas eventually become mature and ready to mate. The colors become darker. The dewlaps are seen under the chin, which means that these lizards are mature and are ready to mate.  

Threats to the Life Span of the Spiny-Tailed Iguana

The spiny-tailed iguana is a food source for the people living in the rural areas of Central America. It is edible,  and their flesh is locally known as medicine. Rural folks say that when you eat the meat of the spiny-tailed iguana, you’ll feel its strength and vitality. Some locals regard the spiny-tailed iguana as a treatment for impotence.

According to some sources, the spiny-tailed black iguana is farmed together with the green iguana as food and export in parts of Central America. to different places around the globe.  

Because of these practices, the population of this species of iguana may become threatened in the future. For now, the conservation status of this lizard is classified as of Least Concern according to the IUCN.

Eating Habits

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The spiny-tailed black iguana is a herbivore, which means it will eat fruits and some plants. Some spiny-tailed iguanas are also carnivores, and their diets include small animals such as bats, rodents, frogs, small birds, and insects. Some experts also eat the eggs or their own young. There was one case when the tail of the same species of iguana was seen in the stomach of an adult male iguana. This could mean that these lizards may also possess cannibalistic behavior. Meanwhile, juvenile spiny-tailed iguanas are initially insectivorous but become herbivorous once these turn into adults.  

Spiny-tailed iguanas are very good at climbing and will love to snack on any food that it will find on trees. These iguanas have very strong stomachs as these can eat the fruit of the manchineel, which is a very poisonous tree. It can even live in the branches of this poisonous tree.   

Supplements for your pet iguana

Fresh food is the key to your pet’s good health. Never feed your iguana cat food! Old beliefs include feeding iguanas cat food can bulk them up, but the protein in this kind of food can cause kidney failure in lizards. Also, feeding inappropriate food can reduce the lifespan of your pets.

To supplement its diet, feed it dark leafy green veggies, fruit, and calcium supplements. Fruit plus calcium supplements must be added once a week.

Young iguanas should eat daily while older lizards may prefer to eat every other day. Avoid any kind of diet that’s rich in protein to prevent kidney problems. We recommend monitoring your iguana’s blood chemistry, especially its calcium levels. This can be done in a vet clinic. 


Spiny-tailed black iguanas don’t live near water; therefore, they are not usually found in the water. However, these lizards still need water to drink. In the wild, these simply lick water or dew on trees and grass. But in captivity, you need to place a dish of drinking water inside the tank. Keep this water fresh and clean at all times.   

Development, Reproduction, and Breeding

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The spiny-tailed iguana becomes sexually mature around 3 to 4 years of life. These lizards gather and breed during specific months of the year. Breeding season usually varies from population to population. 

Males have a pair of organs called the hemipenes. When the lizard is not mating, or it’s not breeding season yet, the hemipenes are found near the cloaca or within the base of the iguana’s tail. But when the males start to mate, the hemipenes are revealed using the muscles in the area, and this is filled with blood. As the males copulate, which usually happens right after the courtship phase, one of the hemipenes is inserted to the female through her cloaca. The sperm move through the grove found in the hemipenes. The retraction of the hemipenes happens after blood rains from the structure. As the hemipenes are withdrawn from the female cloaca, these return to their previous size and position.

During breeding, the oviparous females move to an area where they can lay eggs safely. Usually, females dig holes that are a half meter deep. She will lay around 2 to 24 eggs in the nest and then stay on the spot to defend the burrow.

As mentioned earlier, the young hatch after 4 months in the nest. And since the eggs are deposited deep under the ground, it can take about a week for a hatchling to dig its way out.  

Common Health Problems

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When an iguana is well-cared for and eats a good diet, these are hardy lizards and are rarely sick. Here are the common problems that Spiny -Tailed (Black) Iguanas experience:

Metabolic Bone Disease 

MBD is a common condition in iguanas, and it is the lack of calcium in bones. Symptoms may occur over time, like bowed legs, a rubbery jaw, and kinks in the spine. Calcium is spent when females lay eggs, and this can lead to MBD. Therefore, females that hatch eggs need more calcium in their diets. 

MBD may be treated by increasing vitamin D3 and calcium. Usually, captive iguanas may be given calcium supplements and proper UV lighting to improve vitamin D3 levels in the body. 


Most reptiles have parasites that do not affect their health. But these can become dangerous if the iguana becomes stressed. Also, if the lizard is suffering from an immune system condition. These parasites may multiply and may affect the iguana’s health. 

As the iguana’s condition worsens, the parasites may also affect other animals and humans. To prevent parasites and infections from spreading, place a new lizard in quarantine. Always check for signs of infections like smelly or runny droppings, weight loss, and an enlarged abdomen, An iguana, may also become anorexic and may have a lack of energy. 

Poor shedding

Shedding is important for reptiles, and if poor shedding happens, this usually means that the lizard is in poor health. Take note of signs of poor shedding such as skin shedding in flakes, skin still clinging around the tail or the eyes, and restlessness. Stuck skin should be removed as soon as possible. Dryness is the usual cause of poor shedding, so soaking will help. The lizard must be placed in a dish of warm water for a few minutes. A vet should be consulted right away to remove shedding and to treat wounds or cuts due to incomplete shedding.

Preventing Illness

For captive spiny-tailed black iguanas, keep the tank temperature and humidity at the best levels. Leave a bowl of water the tank for drinking and to improve humidity inside the tank.

Always keep your tank clean because a dirty, unkempt tank leads to the growth of bacteria, and this can affect the health of your lizard. A good cleaning product is important. Also, never use products that leave residue and toxins, which can also harm your pet lizard. 

Your pet needs the best food, so feed it organic food. Buy produce only from stores that sell organic fruit and veggies. Or you can grow your organic food and give this to your iguana  

And as a precaution, quarantine new lizards. These new pets may bring parasites such as mites and other illnesses, so you must place it separately from other lizards. Monitor its health condition before you introduce it to the main iguana tank. Some breeders wait until a few months to quarantine a new lizard.

Some important health concerns about iguanas

Pet iguanas are now becoming very common, but despite this, it is not a good pet for everyone. We recommend that you reconsider having a pet iguana if you have young children if there are pregnant women, elderly people, or people with immunocompromised people in your home. This is because iguanas, like other lizards and reptiles, carry salmonella.

Salmonella infection is a common bacterial disease that can cause intestinal problems. Usually, salmonella lives in the animal and human GUT. This can be transferred through the animal’s feces.


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Physically Aggressive

If a spiny-tailed iguana spots an aggressor, it will do all it can to hurt it. It can bite using its small teeth, or it can use its spines to would the threat. Usually, these aggressive behaviors can be very dangerous, and therefore, you should never approach a stressed iguana. Allow the lizard to calm down before you touch it or pick it up. 

Very Territorial

These iguanas usually live in groups with one male leader. Usually, you can see these basking under the sun together with as many as ten or more lizards in one basking area. Males leaders are very particular about territory, and they would do all they can to protect it, even engaging in a serious fight with possible male threats.

Territorial behaviors include color changes, jaw-gaping, body inflation, rapid nodding of the head, push-ups, biting, and tail thrashing fights. Usually, larger males have larger territories and will mate more often than other male lizards.

Alpha Male

The alpha male is the strongest and not the largest or the oldest. The alpha male will lead the group when feeding and when looking for food. Alpha males usually mate more often than their male constituents.  Alpha Males are always ready for combat due to territorial disputes.                                                                                                              

Male Courting Behavior

You can easily tell if a  male is breeding or court when the males are a bit aggressive. The male lizard always courts the females; however, he will only do so if the female provides the right stimulation. Males may also display their strength and their appearance like puffing the dewlaps, by making their bodies larger and by bobbing their heads to attract females.  

Female Attracting The Males

As mentioned, courting can only happen when the females provide the right stimuli to males. She must respond to the mating calls of males by sexual stimuli. Mating should only happen to a male and female of the same species; otherwise, their children will become sterile hybrids. 

The female lizard must also signal the male that she acknowledges his advances by mature ova that’s ready to be fertilized. 

During mating, males can be very aggressive to the point that these will scratch, bite, and lick females that they think are receptive. 

Young Behavior

Hatchlings will climb from the nest hole together. Experts believe that this is an anti-predator strategy, and thus, small hatchlings can survive.

Mutual Grooming

When spiny-tailed black iguanas become adults, these will remain together and even engage in body grooming; There will be chin rubbing, tongue clicking, and other weird behaviors.                      

Important behaviors for captive iguanas

Iguanas may seem to be complicated animals, but to be a good owner, you must fully understand their behavior. First of all, captive iguanas should be picked up and held regularly to be tamed. This can be difficult for your pet at first because human touch is unnatural to them. It may first resist it, but after regular interactions, it will eventually get used to it.

You need to start early or as soon as you get your pet. Small, baby iguanas can be very quick and can easily get out of your hands and may be difficult to tame, but larger, adult iguanas are lazy and maybe very submissive.  

Some iguanas love climbing on their owners and climbing furniture. Iguanas, especially the spiny-tailed iguana, has sharp claws and a dangerous tail, so be sure to wear protective clothing like long work gloves and safety apron or gear. 

Captive iguanas will not recognize its owners and are never domesticated. It will try to escape, so don’t leave it anywhere. Keep it in a tightly secured cage. The spiny-tailed black iguana can break a man’s bone with its large tail, so start taming it early or as soon as you get it from the pet store. This is not a good pet for a  child or for a person who has other pets or animals in the house.


Shedding should be complete, but some iguanas may suffer from incomplete shedding. This happens when parts of the tail, hands, feet, and eyes shed in flakes. The skin may also remain.. This can indicate problems with humidity and other metabolic conditions as well.

In captivity, you can help your pet with incomplete shedding and encourage complete shedding by improving humidity levels in the tank. Soak your pet in warm water for at least a few minutes to loosen dead skin. Shedding happens more frequently in juveniles and less frequently in adults. Also, take note that shedding is stressful to most lizards, so it’s always best to leave your pet alone. You should only intervene only when there are problems with shedding.


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Iguanas can grow up to 7 feet or more and may weigh up to 20 pounds. An aquarium or a terrarium is just a temporary home for a baby iguana. The best enclosure has to be custom-built and must be placed in a secure and warm area in your home. 

Lighting, Humidity, and Temperature

The Spiny -Tailed (Black) Iguana needs an efficient lighting system, especially when you have a large custom-made enclosure made. An incandescent light or UVB heat light is the most efficient according to pet owners, and a minimum of 12 hours of light to mimic daylight is the best amount of light to improve pet health and tank environment.

Proper lighting will keep the tank interiors at 75 to 90 degrees Fahrenheit in the morning and 80 to 90 degrees Fahrenheit in the evenings. The tank should not drop below 75 degrees Fahrenheit.

You may also use mercury vapor bulbs for very large rooms or enclosures. For a juvenile enclosure, use a compact fluorescent light. Add large branches or shelves in the enclosure so your iguana can climb up and stay closer to the lamp.  

Keep the humidity high inside the iguana tank. Use a humidifier if the iguana stays inside a large room or cage. For a small aquarium for young lizards, improve the humidity by applying a spray of water like a mister. Place a bowl of water is a good way to maintain humidity. Keep this water clean and fresh daily always.  

Tank Bedding and Accessories

Spiny -Tailed (Black) Iguanas should have areas where it can sleep quietly. You can make the enclosure simple or as elaborate as you want, but remember that a more elaborate set up can make it harder for you to see your pet. And your pet’s safety is the most important of all. The accessories inside the tank should be safe, must have no pointed edges, which can hurt your iguana. 

For small enclosures, you can also use accessories made from things at home like a clay pot, an old box, or a plastic container. Place a hiding spot near the lamp or at the back of the room.

For the bedding or substrate, use paper substrate for easy cleaning. For small enclosures or tanks, use newspapers, butcher, packing paper, or paper towel. Do not use sand because your pet can ingest this, and sand can impact its stomach or intestine. Never use substrate materials with too much smell, which can affect the health of iguanas.                                                                                                  


Clean your iguana’s cage with natural, non-toxic cleaners. You can choose from homemade or basic cleaners or commercially available cleaners. Use dishwashing soap, bleach, and water. After a good scrub, rinse everything before you place the iguana inside. Use baking soda to clean the tank and remove yucky odors. 

To use chemical cleaners, follow the instructions carefully. Do not use two chemical products at a time because this can be toxic to your pet. Rinse well with running water and use blankets or paper towels to dry the walls, flooring, and accessories. Place your iguana in once the tank or enclosure is ready. You may also remove odors and bacteria with boiling water and some soap.

Availability – Where to Get One?

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You can get a Spiny -Tailed (Black) Iguana from a local pet store or reptile trade shop online. This lizard is usually from a trader or local supplier (from Central America), and the price for a regular Spiny -Tailed (Black) Iguana is around $30 to $50 depending on the gender. Most pet stores sell this species as hatchlings, and this is an advantage to owners because they can better train and handle their pets.

Of course, the cost of handling, shipping, or delivery of your pet lizard will cost you. This is why some people prefer to buy a lizard directly from a pet store.

Before choosing a Spiny-tailed Iguana as a pet

Some pet store owners will try to sell iguanas to eager customers saying that it will never grow large or it will remain small. All iguanas will grow large and oftentimes, very quickly. Do business only from a reputable dealer or pet store that will give you the correct information about this animal.  

Also, you must check local laws about having a pet iguana. Some places or states may not allow exotic pets and included are spiny-tailed black iguanas. You can use the web to get the latest information about rules on pet ownership in your area. Some places may allow people to care for spiny-tailed iguanas only when it is properly registered, tagged, and cared for by an exotics vet.

How to Care for a Spiny -Tailed (Black) Iguana

Spiny-Tailed iguanas should be cared for using the following techniques:

  • Learn how to handle your iguana early so it will learn to trust you. You must handle it early during the hatchling and juvenile stages. Be patient because it can take time for an iguana to trust human contact. 
  • Wear appropriate safety clothing like a thick work glove when handling your pet. Always keep a close watch when you take your iguana out of its cage or enclosure because this can escape. It can also crawl up on furniture and shelves so never leave it out of your sight
  • Having your iguana registered and checked by a vet can help make sure that it will grow healthy and happy.  Take your pet to the vet regularly, especially when it’s sick, wounded, or lethargic.    
  • Any stress can affect your iguana’s health. You must keep your lizard stress-free to keep it happy and healthy. When shedding, leave your pet alone. Keep the enclosure hydrated and set your humidifier too high to improve room or cage humidity levels. 
  • Avoid overcrowding when taking care of hatchlings and juveniles. Place one lizard in one tank and use smaller tanks for breeding. If you have large, adult iguanas, place each one in its enclosure.  
  • Maintain good humidity inside the tank. This will prevent illnesses, encourage easy shedding, and keep your lizard healthy. If you have a bigger tank, use a humidifier to control humidity effortlessly.
  • Keep the tank in a quiet area and maintain peace when the iguana is asleep. Feed your pet when it’s awake and about. Never leave food rotting inside the tank or enclosure.
  • Change your substrate regularly to prevent mold, bacteria, and parasites. A good substrate should be used but avoid using sand because an iguana may ingest it as it eats. Sand can accumulate inside its gut, causing illness. 
  • Keep tank or enclosure water fresh and clean and don’t remove this inside the tank because this helps improve humidity inside the cage.
  • Feed your iguana the best food. A wide variety of organic produce will do. You may also grow your plants to prevent any pesticides or toxins in food. This can make your pet sick.

FAQ Section

How do iguanas survive in the wild?

Iguanas survive in the wild by eating fruits, and when these are not available, they can also eat insects and birds. Iguanas, like the black spiny-tailed iguana, can climb trees and remain in the branches; therefore, they can reach all kinds of food, adding to their plant-based diet. 

Can iguanas camouflage themselves?

No, camouflaging is not one of an iguana’s traits; it cannot change skin color or adapt to its environment as chameleons do. It can, however, adapt to its environment and stay hidden from potential predators by staying in rocky, dry areas that allow them to blend in. Green iguanas can hide among the trees and shrubs and thus making them hard to find.

Are there plants that an iguana won’t eat?

Although iguanas eat plants, there are some plant species that they stay away from. Iguana-resistant plants are agaves, cacti, begonias, dracaena, bush Alamanda, bromeliads, crown-of-thorns, glory flower, and heliconias.

What do spiny-tailed black iguanas do at night?

Some iguanas prefer to sleep when the climate is too cold or when it’s night time. These animals will remain in their burrows or hiding places to rest and recuperate. When the sun is out, these will also come out to look for food, forage, or interact with other lizards. 

Can iguanas become pests?

Some people are not too happy about having iguanas in their properties and will do all they can to remove them. When the population of iguanas, especially green iguanas, are too numerous, these can settle into human homes, eat food and become very aggressive. 

Are there places that legally kill iguanas?

You should never kill an iguana if you find it squatting in your property. Always seek the help of professionals or pest control service to exterminate iguanas or other reptiles in your home. And if you find iguanas or other lizards, call a professional right away. Never try to capture the lizard on your own. 

What foods are toxic to iguanas?

Iguanas are sensitive animals as well, and there are household items and food which can be toxic to them. Garlic and onions are known repellants of iguanas; the strong smell of onions and garlic can be very upsetting to iguanas, so don’t feed your pet these. Experts say that iguanas don’t know that onions and garlic are toxic and will eat them anyway.

How do you scare iguanas away?

Loud noises and bright lights can scare iguanas away. If you are trying to scare iguanas because these are entering your property, call a professional. You should never face an iguana, especially a spiny-tailed black iguana because these can bite and attack humans. 

What does iguana poop look like?

Iguana poop is brown or black and is often mistaken for small bits of dog food. Adult iguanas may have feces the size of a small dog and are black or brown while their pee looks like thick, clear, and white liquid, which may be expelled alongside their droppings. 

Is the bite of an iguana dangerous?

The bite of an iguana is very powerful, despite not being a carnivore. Adult males can bite each other for supremacy and show their prowess in mating. Therefore, you should never provoke a wild iguana or a lizard in captivity, or you can bite and severely injure yourself.

Are spiny-tailed iguanas poisonous? 

The spiny-tailed iguana is not poisonous; this means you can suffer from a bite, but you won’t get poisoned. Even the meat of this iguana species is not poisonous, and in fact, it is farmed and hunted as food by several Central American peoples.  

Will rat poison kill iguanas?

In large amounts, yes. If you have a pet iguana that has accidentally ingested rat poison, take it to the vet at once. But if you’re trying to kill iguanas in your property, don’t use rat poison and instead, contact professional pest control or animal control services.

Do iguanas poop in the water?

Some iguanas may poop and pee in the water, so you always need to spot check their water and surroundings. Water in the dish inside their enclosure should be replaced daily even if you don’t find poop or pee in it. 

Will iguanas carry diseases?

Yes, there are some parasites and bacteria that lizards like iguanas carry. One of the most common is Salmonella. This is a common disease that involves the gastrointestinal system of humans and other animals, and if not treated right away, this could be fatal.

Can iguanas lick their owners?

Some iguanas can lick the ground, lick their owners, and any object nearby when they are relaxed. If an iguana licks your finger, then this means that it trusts you, and it is very friendly. To achieve this level of calmness, you must take time to handle your pet. 

What is the favorite food of spiny-tailed black iguanas?

Iguanas will likely eat any kind of leafy green vegetable. It will also love a slice of fruit like apples, mangoes, cantaloupes, and many more. Feed these in small slices and just leave these in a bowl inside its enclosure. 

Do all iguanas bite?

Biting is an iguana’s natural way to defend itself, and an iguana that you recently got from a pet store will likely bite because it is new to your handling. You must handle your pet early from the time it has just hatched so it will get used to human contact; don’t forget to use protective equipment to do so.

Do iguanas like to be petted?

Spiny-tailed black iguanas are not used to human contact; therefore, it may not respond well when you first try to hold or pet it. But as you handle your pet daily, it will eventually like to be petted.

Are iguanas aggressive?

Iguanas are naturally aggressive, especially when these are young. They may bite any threat or bite other iguanas to compete for territory. But as the lizard becomes more mature, it will develop a docile attitude. 

Can iguanas become affectionate?

Some pet owners say that their pet iguana has an affectionate nature and can recognize them and even follow them around. Different pet owners and pet lizards have unique experiences. 

Will iguanas spit?

Some iguanas are known to spit because these lizards don’t sweat through the skin but instead, will blow the sweat or moisture from their mouth and nose. 

Can an iguana wag its tail?

Tail wagging is a sign that the iguana is unhappy and when It’s trying to show dominance.  

How can you tell if you have a male or a female iguana?

By the time the iguana is a year and a half old, you can already tell the difference, Male iguanas are smaller and have a more colorful or distinct skin while females have dull skins and marks.

What does it mean when an iguana opens its mouth?

An iguana with an open mouth means that it is too hot. If you spot your iguana with an open mouth, improve the lighting, heating, and humidity in the tank or enclosure.

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