Scientific name – Eunectes murinus
Diet – Carnivorous
Average life span – 10 years
Size – up to 9 metres in length and 30cm in diameter (second longest snake after the reticulated python)
Weight – can weigh more then 250 kg
Native to – Northern South America
Etymology – Eunectes – Good swimmer
– Murinus – Of mice
Description
Eunectes murinus or the green anaconda is by mass, the largest living snake on earth, with an estimated mass of around 250 kg.
Green anacondas are an olive green colour with darker black spots lining its body from head to the tip of their tail. Their bellies are have a yellow and black colouring on their scales.
They are non-venomous, constrictors and opportunistic apex predators.
These enormous reptiles are sexually dimorphic, thus the females are significantly larger than the male snakes.
Reproduction and lifespan
In the wild, green anacondas live for an average of 10 years, however in captivity can live for significantly longer.
Green anacondas are mostly solitary, and reach sexual maturity at 3-4 years old, with females mating every other year during the dry season.
During mating the females will sometimes cannibalize some of the smaller males after which she will not eat again for the 7 month gestation period.
Females then give birth to live young in the water. The 20-40 live young are almost immediately able to swim and hunt by themselves and so they disperse almost immediately.
The largest litter ever recorded was 82 young this is because of the positive correlation between female size and litter size
Anatomy
Due to these snakes being semi-aquatic, they have evolved so that their eyes and noses are positioned on the top of their heads, allowing them to breathe and spot prey whilst almost completely submerged in the water.
Green anacondas, like reptiles, mammals and amphibians have a Jacobson’s organ, which is a part of the olfactory system allowing them to detect chemical signals such as pheromones. It allows them to process chemical signals given off by both their own species and other animals. This allows them to both track their prey and communicate sexual activity towards each other. I order to make use of this ability, they have to flick their tongues through the air in a motion that many of us are familiar with.
This is not the only way that anacondas are able to detect nearby prey, as they are able to distinguish vibrations caused by the footsteps and movements of other animals, as well as identify heat signatures of other animals using pit organs on their upper lips.
Like most snakes, these anacondas are able to detach their jaw in order to swallow prey almost to their own size.
Habitat
Anacondas live wetlands such as slow-moving streams, rivers, swamps and marshes in the Amazon and Orinoco basins in South America. They prefer to move and hunt in the water due to their immense size, being rather impractical on land, compared to the sleek movements they are capable of in the water.
The anacondas that live in areas that flood during the rainy season must move to find water during the dry season or are forced to burrow in mud.
Diet
Green anacondas are carnivore, opportunistic feeders, meaning that they will feed on almost any animal that they get the opportunity to including: rodents, fish, capybaras, birds, turtles, caiman and jaguars.
They have incredibly slow metabolisms, meaning they only have to eat once every few weeks. The exception to this rule however is a breeding female who must eat more to accommodate the amount of energy she is losing in order to grow and incubate her young.
Adult anacondas have no natural predators However the juvenile ones may be predated on by caimans, birds of prey, jaguars and some species of fish.
Classification
They belong in the Boidae family, also known as the Boa family. Although this family is similar the python family for example thy both have a rigid lower jaw and palatal teeth, there are a few distinct differences.
Boas give birth to live young whilst pythons lay eggs, and they lack certain bones and teeth. Their geographical distribution is also different with boas living in the Americas and pythons living in Asia, Africa and Australia.
Conservation status
Green anacondas are noted as of Least Concern on the IUCN Red List, meaning that they are plentiful in the wild and do not need specific wildlife conservation strategies targeted towards them.
