Asian Water Monitor Care Sheet

Scientific Facts

Common Name Asian Water Monitor
Scientific Name Varanus Salvator
Life Span 11 to 25 years
Size 4.9 feet to 6.6 feet
Habitat Lowland freshwater and brackish wetlands
Country of Origin India, Bangladesh, Sri Lanka, Myanmar, Thailand, Cambodia, Laos, Vietnam, Malaysia, and Singapore

Physical Description

Image Source

The Asian Monitor Lizard is one of the larger species of monitor lizards in the world but not as large as the Komodo Dragon. In that regard, these reptiles can grow up to 6.6 feet in length, although there was an instance where an Asian Monitor Lizard kept in captivity was able to grow over 10 feet long. Meanwhile, a mature adult can weigh as heavy as 150 lbs. This lizard normally will not stop growing as it gets older. As such, those kept in captivity are usually bigger than the ones found in the wild, where their life expectancy is understandably lower.

This reptile’s skin tends to be rough or rugged to the touch and comes with patterns or folds that usually are black in terms of color. The skin can also feature dots that are close to yellow or a dirty kind of white in color. Overall, the skin of the Asian Water Monitor is predominantly black or dark brown but has off-white or yellowish markings. Meanwhile, its feet look strong and very muscular, even for a monitor lizard. Each foot has sharp claws at the end.

The head of the Asian Water Monitor is quite long and is certainly “dragon-like” in appearance because of its snout. It has almond-shaped eyes that tend to be moderately big and kinda dark in terms of color. If you inspect its mouth, you will see that it is lined with small yet sharp teeth that look like they were made to kill and tear skin and flesh off of their prey efficiently. Finally, its tail is meant to be a weapon as it is big and muscular and is even twice as long as its body at times.

Gender plays a role in the appearance of the Asian Water Monitor but only as to size. The males are generally a lot bigger than the females and can reach up to 9 feet in terms of length. Meanwhile, the females barely reach 5 feet and are a lot smaller than the males.


Asian Water Monitors have a lifespan of about 10 to 15 years, depending on how it was taken care of. Those who were kept by owners in conditions that are less than ideal for these reptiles usually live less than 10 years. Meanwhile, when taken care of properly, they will most likely reach 15 years. However, captive Asian Water Monitors that are kept in environments that are suitable for their kind and are fed with a healthy diet can live up to 20 years and are generally bigger because of how these reptiles tend to grow indefinitely.

  1. Hatchlings – Asian Water Monitors that have just hatched are usually around 10 inches long and are quite long compared to other types of reptiles. They do not stay as hatchlings for a very long time because they can potentially grow several feet in just under a year.
  2. Juvenile – Juvenile Asian Water Monitors tend to grow quickly and will mature into adults in about 2 years or so.
  3. Adult – Asian Water Monitors reach adulthood at around 2 years or when they have reached more than 3 feet in length. Once they reach that size, they are already sexually mature.

Eating Habits

Asian Water Monitors have a huge appetite because of how large these lizards are. These reptiles, like most monitor lizards, are extremely carnivorous in the sense that they will eat almost anything they see so long as the prey is smaller or weaker than they are. They love stalking their prey and are usually very opportunistic in the sense that, in the wild, they try to catch their potential dinner off guard as much as possible.

That said, the usual Asian Water Monitor diet consists of birds, eggs, rodents, small mammals, lizards, and small reptiles such as baby crocodiles. As long as the animal is small enough, this reptile will most likely make it a usual part of its diet. In captivity, however, most owners usually feed their young or juvenile Asian Water Monitors with gut-loaded crickets and other insects because it is more affordable to do so and because of how gut-loaded insects provide a lot of nutrients that these reptiles cannot get from rodents, birds, or eggs. Always make sure that you feed hatchlings almost every day and juveniles almost every other day because this is when they will tend to grow the quickest.

Gut-loading is when you spray insects with calcium and vitamin D3 supplement or when you feed them with greens that are loaded with the same nutrients. Doing this provides your Asian Water Monitors with the necessary calcium and vitamin D3 they need to balance out the high levels of potassium they get from insects.

But as these reptiles get older, crickets will not fill them up easily. Instead, you can transition them to fish, poultry, and rodents. Asian Water Monitors usually never refuse a meal. As such, you should keep their feeding schedule in check. Adult Asian Water Monitors need to be fed less often. You can feed them with whole prey items about three times a week. But, as they grow bigger and older, you may want to feed them about twice a week.

As much as possible, try not to overfeed them because they will feed on whatever you offer them so long as they have enough space in their belly to eat. Asian Water Monitors have a tendency to become obese. In that sense, you may want to check their feeding frequency as well as the food you give them to avoid health complications caused by obesity.

Sleeping Habits

Asian Water Monitors are diurnal reptiles that are mostly awake during the daytime and asleep at nighttime. That means that they are active when the sun is up but tend to rest or sleep about 12 hours a day or when the sun is already down. However, there are cases where some of these reptiles are quite active at night. The nocturnal activity can happen occasionally depending on certain conditions. At times, they tend to be nocturnal especially when they are hunting for prey at night. But, most of the time, you can expect your captive Asian Water Monitor to be active during the day and asleep during the night.


Their name suggests that Asian Water Monitors are fond of water and are usually found near bodies of water or a constant supply of fresh water. That is why it is normal to find them near mangrove swamps. These reptiles require to be near a reservoir of water because of how the Asian Water Monitor loves to drink water whenever it can. In that case, try to provide them with a constant supply of water in a large enough dish that can fit their entire body.

These reptiles love to submerge in water to rehydrate their bodies. That is why it is essential to provide them with lots of water. In some cases, you may want to set up a pond-like water reservoir in their enclosure. But since they are fond of defecating and urinating in the water, you may want to constantly replace their water with a fresh batch. In some cases, pet owners use a filtration system that automatically cleans and filters the water in the enclosure’s reservoir. However, if you cannot afford one, you might want to regularly change the water in their dish or reservoir to avoid any health complications.

Development and Reproduction

Asian Water Monitors develop rather quickly because of how fast they tend to grow during the early portion of their life cycle. These reptiles will reach their sexual maturity in a quick span of about 2 to 3 years or depending on how big they are.

You can easily tell the male Asian Water Monitors apart from the females. While there are no other physical characteristics that will allow you to differentiate the two sexes, the males are a lot bigger and almost twice as big as the females. Meanwhile, females are generally about 4 to 5 feet in terms of length compared to the males, which are about 6 to 9 feet long when they reach adulthood.

Male Asian Water Monitors reach sexual maturity when they are more than three feet in length. Meanwhile, females are sexually mature when they are more than 20 inches long. It is important to wait for the reptile to reach their mature size before trying to breed them even if you believe they are already old enough for reproduction.

How to Breed

The usual breeding season for Asian Water Monitors is around April because that is when the conditions in their natural habitat are wet. This may continue on until late in the year or in October when the season in most Asian countries are still wet. However, if you happen to live in a region where there are no wet and dry seasons, breeding in Asian Water Monitors happens all year long.

When breeding a male with a female Asian Water Monitor, it is important to house them in a large enclosure that is about 8 feet wide, 8 feet long, and 8 feet high because of how large these reptiles are. You should also monitor a female that is cycling because of how they tend to eat more in an attempt to increase their overall food intake to prepare for reproduction.

Male Asian Water Monitors are very territorial. What that means is that it is best to make sure that there are no other nearby males when you are breeding these reptiles as the male can get very violent if it senses that there is another male that is trying to breed with the female reptile.

Females are not entirely hard to get for the male Asian Water Monitor. They are generally submissive and will allow the male to mate with her so long as she is receptive to mating at that period in time. Larger female Asian Water Monitors will most likely produce larger clutches of eggs.

Common Health Problems

Normally, Asian Water Monitors are hardy reptiles that do not easily get sick as long as you provide them with an environment that is suitable for them and as long as they are eating nutritious food. However, there are times when it can be difficult to avoid sickness, especially if some conditions are unavoidable. Here are some of the more common health issues that these reptiles often face in their lifetime:


Asian Water Monitors are insatiable eaters that do not know when to stop eating so long as there is a constant supply of food. As long as they are not full enough, they will continue to eat whatever you offer them. At times, they might even eat their prey even if they are already past their limit. Overfeeding them will lead to obesity.

While some people might not think that there is no problem with an overweight reptile, an obese Asian Water Monitor will be exposed to a lot more health issues that can potentially threaten its life or shorten its lifespan. As such, it is important to monitor the adult Asian Water Monitor’s feeding schedules as these extreme carnivores will more than likely eat anything you offer them.

Scale Infections

Although the Asian Water Monitor prefers to live in an environment that is humid, you should never leave it in an enclosure that is too humid. That is because having too much water in the air can potentially lead to bacterial and fungal growth that can weaken the immune system of your reptile and cause scale infections.

If you notice that there are lesions on your reptile and that your Asian Water Monitor is lethargic, not willing to eat, and does not seem to be as active as it normally is, then there is a good chance that it is suffering from bacterial or fungal scale infections.

Parasitic infections

Normally, Asian Water Monitors are hardy and resilient reptiles that are not prone to infections. However, wild-caught reptiles commonly have parasites in their systems. While these lizards’ immune system is usually enough to prevent the parasites from overwhelming their internals, wild-caught Asian Water Monitors will most likely undergo stressful conditions during transportation and when they are adjusting to a different environment. As such, the stress will weaken their immune system and will allow parasites to overwhelm their bodies.

Preventing Illness

Preventing illnesses in your Asian Water Monitor is usually a matter of providing them with a good home or environment to live in and giving them the right amount of food that is sufficient for them to reach their required nutrition intake. That means that you should house them in an enclosure that provides them with enough heat and humidity to prevent bacteria and fungi from propagating. You might also want to make sure to never overfeed them to avoid health complications brought about by obesity.

In some cases, it is better to go for a captive-bred Asian Water Monitor to avoid getting a reptile that already carries parasites it got from living in the wild. In all other cases, make sure to have a veterinarian that specializes in reptiles so that it will be easy for you to go to the doctor whenever you want something checked or whenever you feel like your Asian Water Monitor is showing early symptoms of illnesses.


Asian Water Monitors are actually pretty intelligent reptiles in the sense that they are quick to adjust to the different things around them and will learn how to survive in an environment that is totally different from what they are used to. And while they might look big and scary, a lot of owners and breeders treat them as gentle giants because of how easy they are to handle so long as they are used to you. As long as you approach and handle them with caution, these reptiles are generally submissive and will not feel threatened by humans.

Here are some of the other common things that Asian Water Monitors do:


Using their clawed legs and their muscular frame, Asian Water Monitors are excellent diggers that can claw up a garden to find rodents. At times, it is also normal to see these reptiles eating carrion. They have a keen sense of smell that can detect corpses buried underground. As such, in a lot of Asian countries, it is not uncommon to see them digging through the ground in an attempt to unearth a corpse.


The common belief is that Asian Water Monitors are not dangerous creatures in the sense that they will attack humans or bigger creatures at the sight of them. They are generally gentle lizards that usually do not try to attack people. However, they will attack a potential threat when they feel agitated. And when they are threatened, they will not hesitate to bite. These reptiles have mouths that have small but very sharp teeth that were meant to tear flesh. As such, a bite from an Asian Water Monitor is very painful and can potentially be life-threatening because of bacterial infections.

Tail Whipping

Another way that Asian Water Monitor uses as a means of defense is tail whipping. These reptiles have long, large, and muscular tails that are not for show. Instead, they were meant for defense as this lizard uses it as a weapon against potential attackers. A tail whip from an Asian Water Monitor is painful. So, when the reptile is agitated, try to avoid it as much as possible.


If you house your Asian Water Monitor in an enclosure with a large body of water, it is normal to see them swimming and staying underwater for a long time. They are adept swimmers and have leg muscles built to allow them to swim efficiently. In the wild, they can stay underwater for about 30 minutes and are quick enough as swimmers to be able to catch fish, turtles, and baby crocodiles.

Hibernation Cycle

Asian Water Monitors are commonly found in regions where there are only two seasons: wet and dry. That means that they naturally do not experience winter and do not hibernate during the colder seasons. In your case, you will certainly notice that your Asian Water Monitor mostly stays active all year long. However, due to a drop in the temperature during winter, it is normal to see them going through a period of dormancy and will most likely be not as active as they usually are. In that case, it is best to house them in an environment that will consistently keep the temperatures up at optimum levels, especially during winter.


Shedding is perfectly normal in reptiles and in Asian Water Monitors, especially when they are still growing juveniles. This is because they need to get rid of their old skin to make way for a new one to grow and accommodate their growing bodies. In that sense, when your Asian Water Monitor has not reached maturity yet, they will most likely shed more often than adult ones. However, adults will still shed from time to time because these reptiles will grow indefinitely.

It is normal to see your Asian Water Monitor trying to get rid of the skin by rubbing it against rough surfaces. And even when it gets rid of large patches of skin, you might see leftover skin on their toes or on their tail. To make shedding easier, try to mist them with water so that their skin stays hydrated.


As large as Asian Water Monitors are, it is important to keep them in an enclosure that is also quite large. That is why many owners believe that the most challenging part about keeping an Asian Water Monitor is finding space for it. If you are still adjusting as a pet owner, you can gradually increase the size of its enclosure. Hatchlings can be temporarily housed in an enclosure that is about 3′ x 3′ x 3′. But, as they grow older and bigger, you need to upgrade their enclosure. The optimum size of their housing should be about 8′ x 8′ x 8′ because of how big, and active they are.

Asian Water Monitors are climbers. These intelligent reptiles will find a way to escape their enclosure by trying to climb over it. That means that you should try to keep them in an enclosure that has walls that are high enough to prevent them from escaping. You may also want to furnish the enclosure with things they can climb on so that you can allow them to exercise, move around, and be themselves. You can use baskets, shelves, or branches but not plants because of how heavy the Asian Water Monitor is.

You may be able to find commercially sold aquariums or enclosures that are big enough for your Asian Water Monitor. If not, then it is best to build one yourself using sturdy materials that will be able to withstand the size and weight of this gentle giant.

Lighting and Humidity

The Asian Water Monitor is a diurnal reptile that spends its day as an active lizard. Then, at night, it normally sleeps. That means that you should provide it with lighting for about 12 hours a day if you are housing it indoors. If you are keeping it outdoors, then the sunlight will be more than sufficient to provide it with the light it requires.

These reptiles do not require ultraviolet B lights, but they will be able to benefit from the full-spectrum light source. It might be best to use lights that are hot and bright enough. Some owners tend to light up only a select area where the Asian Water Monitor is allowed to bask while keeping a portion of the enclosure dark for hiding or sleeping. Meanwhile, some prefer to light the entire enclosure up.

As regards to humidity, Asian Water Monitors require an environment that is very humid so as to keep their bodies hydrated. Try to keep humidity levels at about 60% to 70%. To aid in increasing the humidity in the enclosure, use a large water dish that will not only provide a water source but also a soaking area for your Asian Water Monitor. In all other cases, mist the enclosure as much as possible to keep humidity levels up.


Asian Water Monitors are used to environments that are hot and humid. In that sense, it is important to keep them in an enclosure that provides a lot of warmth. The best way to do so is to use a light source that is strong enough to provide them with the warmth they need. Incandescent bulbs may do the trick for you. An enclosure that is about 90 degrees Fahrenheit may be warm enough.

However, what is also equally important is to provide them with a basking area that is warmer than their usual habitat. Lizards bask under the warmth of a light source to aid in their metabolism. In that case, provide them with a basking area that has warmth in between 125 and 140 degrees Fahrenheit. You can use floodlights for their basking area. In some cases, owners prefer to only keep an area lit for the reptile’s basking area while keeping the rest of the enclosure dark.


As with any pet, it is important to keep the Asian Water Monitor’s enclosure sanitary enough for it. That means that you should clean it regularly to prevent bacteria from building up. The more important part is to make sure that you replace the water in the dish as regularly as possible because they love to defecate in the water while submerging their bodies. Some owners use a filtration system, but you can do without it so long as you are dedicated enough to replace the water and sanitize the dish regularly.

Natural Environment – Substrate

There are plenty of substrate types you can use for your Asian Water Monitor’s enclosure. Some people use natural substrate such as soil, mulch, or orchid bark because they are safe for the reptile. Dirt is also a fantastic choice because it allows the lizard to burrow through it. You may also use newspapers, but they get easily destroyed by the weight of the lizard and the sharp claws on their legs.


Asian Water Monitors love the water and often stay submerged in a body of water for hours. They try to keep their bodies hydrated as much as possible and are often found near bodies of water in the wild. That means that the best way to make sure they stay hydrated is to keep a large water dish in their enclosure. You should also mist the entire enclosure with water from time to time to make sure that the environment stays humid and moist for your lizard.

Availability – Where to Get One?

Asian Water Monitors can be purchased from exotic pet shops that sell either captive-bred reptiles or wild-caught lizards. Captive-bred Asian Water Monitors are generally recommended because of how they are healthier and much more suited to living in a captive state than wild-caught ones, who usually come with parasites. Captive-bred lizards are also easier to handle as they are used to live around humans.

How to Care for an Asian Water Monitor?

Here are some tips on how to care for an Asian Water Monitor:

  • Asian Water Monitors, especially the captive-bred ones, are usually receptive to human care and interaction but should still be handled with caution because of their strong and painful bites and sharp claws.
  • It is important to keep their enclosures hydrated enough because these reptiles prefer an environment that is very humid.
  • Try to keep them away from food as much as possible when it is not feeding time because they are prone to obesity. When they are obese, Asian Water Monitors are prone to a lot of diseases and illnesses.


What do I feed my Asian Water Monitor?

Asian Water Monitors are carnivorous reptiles that will feed on almost anything small enough to fit its mouth. That means that it loves feeding on fish, insects, rodents, small mammals, baby crocodiles, and birds.

Are Asian Water Monitors good for beginners?

It really depends because Asian Water Monitors are quite gentle and are receptive to human care but are also challenging to take care of because of their size.

How often should you feed your Asian Water Monitors?

This depends on their age. Hatchlings and juveniles require regular feeding of about three times a week while mature ones should be fed about twice a week.

Can you feed Asian Water Monitors with vegetables?

Greens and vegetables do not form part of the regular diet of Asian Water Monitors, which are exclusively carnivorous.

How big can an Asian Water Monitor get?

Asian Water Monitors never stop growing and will grow indefinitely. Males can grow to as long as 10 feet while females rarely exceed 6 feet.

Do you have to keep the light on for the Asian Water Monitor at night?

Asian Water Monitors are diurnal reptiles and are active during the day and asleep during the night. You do not have to keep the lights on at night, but you may have to provide them with enough heat.

Are Asian Water Monitor lizard bites dangerous?

There is no consensus as to whether or not Asian Water Monitors are venomous. However, their bites are still potentially dangerous when left untreated because of the bacteria that could have been transmitted from their mouth onto your open wound.

Do Asian Water Monitors bite humans?

Generally, Asian Water Monitors are receptive to human care, but these gentle giants will still bite or attack you if they feel threatened by your presence.

How long can an Asian Water Monitor stay underwater?

Asian Water Monitors are adept swimmers, and they love the water. They can potentially stay for up to 30 minutes holding their breath underwater while hunting for water-based prey.

Do Asian Water Monitors hibernate?

Asian Water Monitors do not hibernate because they come from regions that do not experience winters. However, when the season gets too cold, they may actually undergo a period of dormancy and will not be as active as they usually are.

Is it okay to pet or carry an Asian Water Monitor?

Asian Water Monitors are not aggressive reptiles and are generally very receptive to human care. That means that you may be able to carry or pet them as long as you exercise the necessary caution in handling these gentle giants.

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