Green Anaconda Care
The Green Anaconda (Eunectes murinus) is known to many as the world’s largest snake, though they may not get quite as large as one might think. Make no mistake, they are still huge snakes with some very serious power. There are four species of anaconda in the genus Eunectes. They are E. murinus, E. notaeus, E. deschauenseei, and E. beniensis. Green and yellow anacondas are the only two species of anaconda known to be commonly kept in captive collections (i.e. zoos, private breeders, and private reptile keepers). Green anacondas can attain lengths of over 16’ in captivity. Adult females are typically seen around 12-14’ and males are known for typically reaching around 8-10’ though they can certainly get larger than that. Keeping green anacondas in captivity should only be considered by the experienced reptile keeper or herpetoculturist. They are a very rewarding species to keep.
Scientific name : Eunectes murinus
Distribution : Brazil, Bolivia, Paraguay, Colombia, Peru, Venezuela, Guyana, Suriname
Average Size : 10 - 14 feet
Life Span : 25 years or more
Difficulty : Intermediate/Advanced
Starting off, neonate green anacondas can be kept in 16-32qt tubs or an equivalent size enclosure. You don’t want to start off with something too large as this may make the snake feel insecure and stressed, leading to trouble getting the snake to eat. Glass aquariums are NOT recommended as they are intended for fish, not reptiles. They do not hold in heat or humidity well and are often very heavy compared to much better caging options. Many keepers use commercially available snake racks for young anacondas and custom PVC or wooden snake cages for larger juveniles and adults. Snake racks are ideal for young anacondas as they are often opaque with the front being open so that the tubs slide in and out. These hold heat and humidity very well and make most snakes feel more secure as they are not in direct light. Be sure to have ample ventilation to avoid mold growth, due to keeping such high humidity. For an adult green anaconda, you are going to be looking at a cage that is at least 8-10 feet in length and 3-5 feet deep. The more room, the better as long as you can provide proper heat and humidity levels. Your anaconda’s set up can be as simple as paper substrate with a hide and water tub, or as elaborate as a custom natural looking set up with soil, decorations, and a large filtered water source to soak and swim.
A hide box is used to help a snake feel more secure and hidden. Many young anacondas will utilize places to hide. They tend not to use them as often as they grow larger in size but you can still offer hides throughout the snake’s life. The size of the hide box should be just big enough to allow the snake to fit snug inside. This makes them feel as though they are hidden from predators and is vital for some snakes to feel comfortable and not cause any issues such as stress, which leads to some snakes not wanting to eat.
There are several options for substrate that can be used. I personally use coco-fiber bedding for neonates and juveniles and usually Kraft paper for adults. When using loose substrate, 3-4 inches of depth or more is sufficient to allow burrowing and the ability to spot clean. Coco-fiber holds humidity extremely well and is very absorbent. Aspen bedding is another common substrate used for snakes but is not recommended for anacondas as it tends to be better suited for drier environments. Cedar and Pine shavings should be avoided as they can be toxic to reptiles.
Lighting – Heating
Green anacondas do best under natural day and night cycles. Full spectrum UV lighting can be added to the enclosure in order to provide artificial lighting for your snake but it is not recommended to be left on for extended periods of time. Anacondas can and will bask if given the opportunity. A 12 hour day and night cycle can be easily achieved using a standard outlet timer.
There are a few different options for heating but your end goal is to achieve a hot-spot of 88-92°F with a cool end of 78-80°F on the other side of the enclosure for the snake to cool off. I use a heat pad under one side of the enclosure for my neonate enclosures to provide the snake with “belly heat” which will also require a quality thermostat to ensure that the heat pad does not get too hot or too cool. Without a thermostat, many heat pads will continue to heat up to the point of burning the enclosure/animal and possibly injuring your snake and starting a fire. For adult enclosures I recommend radiant heat panels. Heat pads won’t be able to work as well if you offer your snakes a deep substrate as the heat won’t pass through easily. Radiant heat panels are mounted on the ceiling of the enclosure and the provide a more natural type of heating since they heat from above as the sun does in the wild. Ceramic heat emitters or heat bulbs can also be used but ensure that the enclosure is still retaining adequate humidity as heat bulbs tend to dry enclosures out.
Coming from the Amazon Rainforest, green anacondas are a semi-aquatic species of snake so they require a water source large enough to fully submerge and swim in. You should aim for a water temperature of 80-84°F. Anacondas will typically spend a large majority of their time in the water as much of their time in the wild is spent swimming through swamps and rivers. The water source should be cleaned and changed out every few days to avoid any health issues. It is helpful to add a powerful filter to keep the water clean. Anacondas will often defecate in their water as well so be sure to clean the water immediately when this occurs.
Anacondas have high humidity requirements, and this can be achieved with regular misting or usually just by having a large water source and moist substrate. Coco-fiber bedding comes in handy here also as it absorbs and holds moisture which will raise humidity levels. If you live in a dry region, you may have to mist more often than someone living in a more humid region. You can also move the water source closer to the heat source to raise humidity. A good humidity range for anacondas is between 70-80%. That is the average humidity range in their natural habitat. It’s not uncommon to see condensation on the walls or ceiling of the enclosure. Be sure to have very good ventilation as well so that the enclosure does not become muggy and constantly damp. This can lead to health issues which will be addressed later.
Neonate green anacondas will typically start their lives by eating birds such as small quail or chicks or even small fish, although the preferred diet is a variety of prey such as rodents, birds, fish, and other small mammals. Usually they can be switched to rodents after a few feedings. Some less picky anacondas may start off eating live or frozen thawed (f/t) rodents right away. It is best to offer f/t prey, but some snakes will start off only eating live prey. It is important to get your anaconda eating f/t prey as soon as possible because some live prey have the potential to seriously injure or even kill your snake. If live feeding is your only option, be sure to supervise the entire feeding and intervene if necessary. Large live prey such as rats or rabbits can inflict a serious bite or cut to a constricting snake. As adults, green anacondas will normally take adult rabbits, guinea pigs, and rats as their staple diet. You can also still offer birds such as chickens and even some types of fish to your anaconda to add some variation to their diet. Neonate anacondas are commonly fed once every 7-10 days, with juveniles being fed about every 10-14 days. Adult anacondas should be fed an appropriately sized meal once every two-four weeks depending on the size of the meal. If it is a very large meal, they can certainly go even longer between feedings.
Green anacondas can be known to be defensive and they are very powerful snakes. When these snakes are born, they are often quite defensive as this is a stage in their life where many of them would fall prey to a predator in the wild. With regular handling they tend to get much more tolerable of human interaction as they grow. Snake hooks are normally used to assist in maneuvering defensive snakes but are not recommended to be used to lift large anacondas as they are heavy bodied snakes and all of that weight on a thin hook could easily break their ribs. It is best to carefully use a snake hook just to nudge the snake before picking them up, so they know it is not time to eat. Gently pick up the snake using your hands and always keep an eye on the snake’s behavior. Some of my anacondas have stayed defensive but most of them are fine to be handled as they are accustomed to it. In fact, one of my adult female anacondas is probably the calmest and friendliest snake I own, out of dozens of different species.
Cleaning largely depends on when the snake defecates or urinates. This is typically weekly for most snakes so you should be cleaning the enclosure often to avoid any bacteria growth or other health hazards. If you use substrate such as coco-fiber, often times you are able to spot clean the area and just fill it in with new substrate. Substrate should be fully replaced every few weeks and a thorough cleaning of the entire enclosure is necessary.
These snakes typically do not have many issues with shedding as their humidity should be kept higher than most snakes and they should have a constant large water source to soak in. Younger anacondas shed every few weeks and their shedding slows down as they age. Adults may only shed every few months. A snake fed more heavily would typically shed more than a snake fed less often, as that snake would be growing faster. If there does happen to be a problem with stuck shed, simply up the humidity and take the snake out and put it in a container/tub to soak for a couple hours if it will not soak on its own. The shed skin should come right off during or after the soak. If not, continue the sessions of soaking for the following few days. Just be sure not to pull the shed off if it does not very easily come off as this may result in tearing of the skin or pulling off scales.
Potential Health Problems
One of the most common health problems in snakes is upper respiratory infection (URI). This can be caused by many factors and can potentially lead to death if left untreated. URI’s are commonly caused by inconsistent heat and humidity. The best cure for a URI is to ensure all of the care requirements are being met and seek Veterinary assistance immediately.
These snakes are often susceptible to water blisters. This can happen if a snake soaks in water that is unsanitary or the snake is living in unsanitary conditions in general. This can often be avoided or corrected by keeping the enclosure and water source clean and cleaning the snake’s enclosure immediately after it defecates/urinates. If your snake develops water blisters, a vet visit is recommended to avoid infection and further issues if the problem doesn’t quickly clear up with proper husbandry.
Anaconda – The Secret Life of the World’s Largest Snake – Jesús A. Rivas
Anacondas (Professional Breeders Series) – Hans Bisplinghof & Henry Bellosa
Please note that this care sheet is based solely on the opinion and experience of Fisher Reptiles and it is always recommended to obtain your research from multiple sources to decide what's best for your animals.