Olive Sea Snake Fact File

Aipysurus laevis








Wild - 15 years

Captive - 15 years



Fish, Eggs

conservation status


Lest Concern

A Snake at Sea!

Olive sea snakes are found in the waters around the coastline of Australia and New Guinea along with a number of smaller offshore islands in this area.

This species is equipped with a potent venom which can be used to subdue their prey and will also effect humans if they are bitten.

Appearance - What does an Olive Sea Snake look like?

The olive sea snake is a long sea snake with smooth scales which are variable in their coloration. Most have olive skin along the back with pale, speckled skin along the sides. On the head the scales are a darker brown. Some individuals though are a flat olive-grey across the entire body.

They have the longest fangs of any sea snake.

They can grow to lengths in excess of 2m (6ft). Their weight may be up to 3kg (6.6lbs).

Adaptations - How does the Olive Sea Snake survive in its habitat?

Like all snakes they have no limbs. As sea snakes they are adapted for swimming with the body being slightly compressed and the tail is flat and oarlike.

To prevent air entering the lungs while they dive underwater they have a valve which is engorged with blood to hold it shut when they dive.

Diet - What does an Olive Sea Snake eat?

Olive sea snakes are carnivores. Their varied diet can include fish, eggs, crustaceans and molluscs.

Their prey is subdued using a potent venom. Once the venom is ingested they will coil around the prey and hold it till it stops wiggling. The venom of the olive sea snake works on the muscles and nerves of their prey and begins to break down prey from the inside to assist with digestion.

The venom is potentially lethal for humans if bitten.

Range - Where do you the find the Olive Sea Snake?

Olive sea snakes can be found in the waters along the northern coastline of Australia across towards New Guinea as well as other tropical areas in the south-west Pacific ocean. In Australia they range from the West Australian coastline around to Queensland.

Habitat - Where can an Olive Sea Snake survive?

They make their home around coral reefs, estuaries and tropical shallows. They tend to be found in areas with a sea depth of 4-45m (13-147.6ft). They seem to favour more protected reef areas.

Areas of coral are used as shelter. Tracking has shown that they do not make use of the same shelter sites regularly.

Snake News Stories

Reproduction - How does an Olive Sea Snake produce its young?

Breeding takes place from May to July.

The entire life cycle of the olive sea snake takes place underwater. Mating occurs under water and lasts long enough that they need to surface to breathe during. The female will swim to the surface dragging the male with her as they go.

Often several males will attempt to gain breeding rights with the same female.

Females give birth to live young underwater. They may have as many as 11 young though the average is 6. Older females tend to produce a larger number of young. They will typically reproduce once every two years taking the middle yar to

Young are darker in coloration than the adults and will lighten as they age.

Sexual maturity is reached at 3 years old for males and 5 years old for females.

Behaviour - What does the Olive Sea Snake do during its day?

The entire life of the olive sea snake is spent underwater. Storms sometimes wash them ashore and this is often fatal for the snake.

They can remain underwater for up to 2 hours before they need to surface to breathe.

Olive brown sea snakes have a venom which is used to subdue prey. They are inquisitive towards humans and sometimes bite people. These bites can be fatal.

Hunting tends to occur at night when they will emerge from their hiding places.

Olive sea snakes need to shed their skin throughout their life. This helps them to grow and removes barnacles and algae from the skin. This is achieved by rubbing against coral or rock. Shedding occurs every two to six weeks which is more often than land snakes.

Salt is excreted by a gland under the tongue to prevent excess salt accumulating in their body.

Predators and Threats - What stops the Olive Sea Snake from surviving and thriving?

Their predators include sharks and birds such as the osprey.

Humans affect their population by accidentally catching them in fishing nets. Many of their preferred prey species are targets of fishery operations bringing them in to regular conflict.

Climate change is impacting this species through coral bleaching. When coral dies off the species will lose its habitat along with their food source.

Quick facts

They are also known as the golden sea snake or olive brown sea snake.


Ambrose, J., 2015. Wildlife Of The World. 1st ed. London: Dorling Kindersley.

Crowe-Riddell, J.M., Courtney, T., Rasmussen, A.R. & Sanders, K. 2021. Aipysurus laevisThe IUCN Red List of Threatened Species 2021: e.T132475824A83766285. https://dx.doi.org/10.2305/IUCN.UK.2021-2.RLTS.T132475824A83766285.en. Accessed on 19 February 2023.

Wildscreen Arkive. 2020. Olive-Brown Sea Snake (Aipysurus Laevis). [online] Available at: <http://www.arkive.org/olive-brown-sea-snake/aipysurus-laevis/> [Accessed 27 August 2020].

Oceana. 2020. Olive Sea Snake. [online] Available at: <https://oceana.org/marine-life/sea-turtles-reptiles/olive-sea-snake> [Accessed 27 August 2020].

Britannica Kids. 2020. Olive Sea Snake. [online] Available at: <https://kids.britannica.com/students/article/olive-sea-snake/312806> [Accessed 27 August 2020]

Department of the Environment (2023). Aipysurus laevis in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: https://www.environment.gov.au/sprat. Accessed Sun, 19 Feb 2023 16:47:18 +1100.

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