Green Anaconda Care

The Green Anaconda, Eunectes murinus, holds the distinction of being among the world's largest snakes, a title substantiated by its substantial size and formidable power. As of February 2024, the genus Eunectes comprises three recognized species: E. murinus (Southern Green Anaconda), E. akayima (Northern Green Anaconda), and E. notaeus (Yellow Anaconda).

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Eunectes murinus, the Southern Green Anaconda, is the most prevalent species within herpetoculture, and consequently, this care sheet will focus on its husbandry. Previously, E. deschauenseei (Dark Spotted Anaconda) and E. beniensis (Beni Anaconda) were recognized as distinct species, but recent taxonomic revisions have reclassified them as E. notaeus. The taxonomy of Eunectes remains an area of ongoing research, and for the latest findings, refer to this link.

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In captive collections, including zoos and private herpetoculture, E. murinus and E. notaeus are the primary Eunectes species being kept. Eunectes murinus exhibits significant sexual dimorphism, with captive-bred females exceeding 12-16 feet in length, while males typically attain 8-12 feet, although larger individuals are documented.

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The husbandry of Eunectes murinus demands a high level of expertise, making it a species suitable only for experienced herpetoculturists. However, for those with the requisite knowledge and commitment, E. murinus offers a profoundly rewarding experience.

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• 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

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Housing

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​In our experience, neonates are best housed in enclosures ranging from 16 to 32 quarts, or equivalent dimensions. Initiating husbandry in excessively large enclosures can induce stress and insecurity, potentially leading to a refusal to eat. Glass aquariums are NOT recommended for snakes due to their inherent design, which is optimized for fish, not a reptile that prefers to be secluded. Glass enclosures exhibit poor thermal and humidity retention and are often unnecessarily heavy compared to more suitable caging alternatives.

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For young anacondas, commercially available rack systems are frequently utilized for neonates and young juveniles, while custom-built PVC or wooden enclosures are recommended for larger individuals. Rack systems, typically featuring opaque sliding tubs, provide optimal thermal and humidity stability, while also offering a sense of security due to opaque tubs. Adequate ventilation is crucial to mitigate the risk of fungal growth associated with high humidity levels.

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Adults require enclosures with a minimum footprint of 8-10 feet in length and 3-5 feet in depth. Larger enclosures are always preferable for adults, provided that appropriate thermal gradients and humidity levels can be maintained. Enclosure design can range from minimalist, utilizing paper substrate, a hiding spot, and a water basin, to elaborate, naturalistic setups incorporating soil substrate, enrichment, and a large, filtered aquatic feature for soaking and swimming. We should strive to provide these incredible animals the best possible care.

 

Hiding spot

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Providing a retreat, or hide, is essential for promoting a sense of security in snakes. Neonate anacondas, in particular, exhibit a strong tendency for seeking concealment. While they may not utilize their hide all the time, offering areas of concealment throughout the animal's lifespan remains beneficial.

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The dimensions of the hide should allow the snake to fit snugly, mimicking the natural crevice-dwelling behaviors that provide a sense of security from perceived predators. This is particularly crucial for mitigating stress, which can manifest as subsequent feeding refusal in some individuals.

 

Substrate

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A variety of substrates are suitable for green anaconda husbandry, each with distinct advantages. For neonates and juveniles, coco-fiber bedding is frequently utilized due to its exceptional absorbency and resistance to mold, maintaining optimal humidity levels without sacrificing air quality. Adult individuals are often maintained on kraft paper, which facilitates ease of cleaning and observation.

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When utilizing loose substrates, a minimum depth of 3-4 inches is recommended to enable natural hiding behaviors and facilitate effective spot cleaning. While aspen shavings are commonly used for snakes from drier climates, they are not recommended for anacondas due to the incompatibility with this species' high humidity requirements. Furthermore, the use of softwood shavings, such as cedar and pine, is strongly advised against due to a potential toxicity 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. Arcadia Reptile has top quality reptile lighting options. You can find their products here. 

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Maintaining a precise thermal gradient is critical. A basking area temperature of 88-90°F should be established, coupled with a cooler ambient temperature of 78-80°F at the opposing end of the enclosure, allowing for thermoregulation. For neonates, ventral heating via under-tank heating, regulated by a high-quality thermostat, is recommended. Thermostatic control is imperative to prevent injury and potential fire hazards, as unregulated heating sources can and will reach dangerously high temperatures. I cannot stress the importance of a high quality thermostat enough as accidental fires are far too common in herpetoculture. For adult enclosures, radiant heat panels are preferred. These provide a more naturalistic heat source, emulating heat from above. Under-tank heating pads are less effective with deep substrate layers, as thermal transfer is impeded. Ceramic heat emitters or incandescent heat lamps can also be used, but careful monitoring of ambient humidity is essential, as these sources tend to reduce humidity in the enclosure.​

 

Water

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Originating from the Amazon Rainforest, green anacondas are a semi-aquatic snake, requiring a water feature of enough volume to allow complete submersion and room to swim. Maintaining a water temperature within the range of 80-84°F is recommended. Placing your water source closer to the heat source can help keep it warmer while also doubling as a humidity boost. Green anacondas will usually spend a lot of time in water, mirroring their natural behavior of traversing bodies of water.

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Regular water changes are essential to minimize the risk of health issues. Implementing a robust filtration system is highly recommended to maintain water quality. Anacondas frequently defecate in the water; therefore requiring frequent cleaning as a clean water supply is crucial to the health of these animals.

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Humidity

 

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.

 

Feeding

 

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.

 

Handling

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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

 

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.

 

Shedding

 

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.

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Recommended Literature

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Anaconda – The Secret Life of the World’s Largest Snake – Jesús A. Rivas

Anacondas (Professional Breeders Series) – Hans Bisplinghof & Henry Bellosa

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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 is best for your animals.