This website use cookies, to enhance navigation performances. Clicking OK or continuing to browse the user accepts cookie utilization.


Eunectes notaeus (COPE, 1862)

Yellow Anaconda

Class: Reptilia
Order: Squamata
Suborder: Ophidia
Superfamily: Henophidia (Booidea)
Family: Boidae
Subfamily: Boinae
Genus: Eunectes
Specie: notaeus

Geographical distribuition and biology

Eunectes notaeus lives in Bolivia, Paraguay, Uruguay, West Brasil, North-Est Argentina.

It lives in the rainforests along / near the rivers, in wetlands and floodplains, where it feeds on mammals, fish, birds and other reptiles such as turtles. He spends a lot of time immersed in water, or in the mud.


The head is relatively small and not very distinct from the body.
Females reach an average size of 250cm; but they can get to 300 cm without too much difficulty. The males, much smaller, can reach 200cm, although generally stop just over 150cm.
Other signs of sexual dimorphism , as well as the different dimensions of adult specimens, are the length of the tail and the development of spurs; both greater in the male.
The body color is yellow, sometimes light , sometimes dark , sprinkled with irregular black circular spots , which can be clearly defined and marked, or nuanced and not net.
They have powerful and toned muscles , which allows them quick and powerful shots . I would say that for the same size with a Boa constrictor imperator , the strength of Eunectes notaeus is considerably higher. This too, in addition to the more authoritarian and proud temperament (despite the timidity of the young specimens , or not yet acclimated) makes this species not suitable for those who have no experience with big constrictors .

Terrarium and breeding

The breeding of Eunectes notaeus does not differ from that of the Boa constrictor imperator, except for the most attention to the container of water, which in addition to comfortably hold the snake in question must also allow it some comfort of movement within, as that it will pass inside several hours every day.

The average temperature should be about 28-29 ° C, with a humidity fairly high, but not exaggerated, I would say between 60% and 80%. During the night, it is good to lower the temperature by a few degrees, bringing it to 24-25 ° C.
Considering the size, the males should be kept in terrariums over 100cm in length (the larger the size reached by the snake, the greater should be the size of the case), while to the females should be dedicated an area of ​​at least 150cm. If you consider that the water container must have significant size, it follows immediately that the above measures should be increased in relation to the size of the water tank.
Do not underestimate the height of the terrarium, as Eunectes notaeus is able to do some good climbing!
According to our experience, is to avoid the use of a water-terrarium or a paludarium, owing to the difficulties that would be encountered in the management and to keep good hygienic conditions. In addition, the snake in the theca must be able to choose whether to stay in the water or in a dry area of terrarium, and in a paludarium this is not so obvious.

It is Important the presence of a den, because often Eunectes notaeus is quite shy and timid, especially when Anaconda is young or recent purchases and not yet acclimated.

The ideal substrate should be of very absorbent material, given the amount of liquid manure which accompany the feces and urates.
We always used sphagnum peat (blond peat) for relaying this boid, and the results have always been satisfactory: it is sufficient to remove the dirty part and replace it with clean peat and periodically replace the entire substrate.
The myth that these animals constantly emanate bad smell is wrong, untrue. This is limited to defecation. It follows that animals housed in a bad way or kept in unhygienic conditions produce an unpleasant odor consistently, but it is farmer’s fault, not of the snake.
Even about the character of these snakes, people talk too much, so much so that anyone who hasn’t it ever raised "know," that it is particularly aggressive and restless snakes.
On the contrary, despite having to admit that the character of Eunectes notaeus is certainly not that of a Panterophis guttatus (Elaphe guttata), as if Anaconda is disturbed, it do not hesitate to blow and biting. I can confirm that, once set, and if well kept and fed, this snake is not too restless to an imperator. One of our specimen let himself handling safely during the cleaning of the terrarium, and when began to get nervous he did understand us by getting a little 'more agitated, and looking for a way to escape. Then it became sensible to store it in the terrarium and let it quiet, but we were left a good margin of time before it started to other reactions. Some bite has deployed in his life, not so much to make it classified as aggressive animal.

Once they are acclimated they feed much voraciously, but you may find difficulties with newly purchased specimens. In these cases, calm and tranquility are the best partner of every breeder. For us it was enough to leave a prey thawed, in front of the lair in the evening, to see it disappear in a couple of hours. But after several weeks of acclimatization it ate from the gripper exactly like an imperator, although with a more sudden and powerful shooting.

Notes and comments

The characteristics of the housing this species , combined to the character fair and shady, along with his strength and power, make it a species not suitable for beginners. It is good to know their habits, and have prior experience with large constrictor.


Angelo Cabodi
Silvia Tangredi

2013-2019  SQUAMATA, the herp land!, sponsored by