The Aipysurus laevis, known by its common name Olive Sea Snake, is a venomous aquatic snake that inhabits regions in the Indo-Pacific. Other names associated with the olive sea snake are golden sea snake and olive-brown sea snake.
Featured image credit: Malcolm Tattersall
Appearance
Like its namesake, the olive sea snake has distinctive brownish, olive, and purple smooth scales. The snake is not a small reptile by any means, as it can reach lengths of up to 2 meters, and most commonly 1 meter.
The venom of the olive sea snake is some of the most powerful and effective of all sea snakes. The potent venom stops its prey in its tracks with its bites. The venom is so strong that it targets the nerves of its prey and essentially paralyzes them. Its prey includes crabs, fish eggs, fish, and other crustaceans.
The long sea snake has a paddle at the end of its body that helps propel itself through the water.
All along their entire body, their olive skin contains remarkable photoreceptors. This development allows them to sense when they are completely hidden from light and thus hidden from view. This is vital in being such effective predators and also in staying away from potential attacks from larger animals.
Habitat
The olive sea snake avoids the open water, opting for coral reefs and rocky, small cave-like crevices to occupy.
They occupy the Great Barrier Reef, and other protected reef areas, in the Coral Sea around regions such as Australia and Papua New Guinea. In fact, they are considered to be one of the most common species of sea snakes found in the coral reefs of Australia.

Credit: Sylke Rohrlach (CC BY SA 2.0)
Typically, olive sea snakes exist in tropical shallows of around ten to forty meters in depth but have been known to venture as far as seventy meters below sea level.
Diet
Like many sea snakes and land snakes, the olive sea snake is a carnivorous creature. They hunt and feed on crustaceans, fish, and other marine species. They typically will search inside crevices and holes in reefs for potential food.
These carnivores are also known to target the eggs of fish and marine animals for an easy lunch. Incredibly, the venom of the snake works by breaking down the muscles and bodies of prey for quicker and smoother digestion when it comes to processing the meat.
Reproduction
Like many species on earth, the olive sea snake females differ from the males in their behaviors and reproductive cycles. For example, females take around their fifth year to reach sexual maturity, whereas males only take three years.
One very funny observation is that scuba divers have been known to get caught up in the mating ritual. Male sea snakes have been known to mistake divers for female sea snakes and have approached them in open water. their courtship consists of a large gathering of male sea snakes all battling it out to win the approval of one female partner.

Credit: Richard Ling (CC BY SA 2.0)
The eggs get fertilized internally, and, like humans, it takes nine months for the egg to hatch. Although there have been incidents of olive sea snakes giving birth to up to eleven young, on average, a female can only manage around five.
Despite a small number of external threats, the entire life cycle of the olive sea snake is only around fifteen years.
Threats
The habitat that we find the olive sea snake in doesn’t have many threats to contend with. It is only reef sharks, larger sharks, and predatory birds, such as osprey, that target the snake.
Like many modern ocean animals, humans have a part to play when it comes to causing potential harm.
With the increased number of scuba divers exploring reefs and coral habitats, there is always a risk of disturbance or contamination, which can contribute to habitat loss. However, this is a minuscule threat in relation to fishing and prawn trawls. Prawn trawling is where vast fishing nets geared towards prawns and other crustaceans are pushed across the sea floor and capture everything in their path. It is said that around 50% of olive sea snakes that get caught in these nets are killed.
Pollution and climate change also have a knock-on effect and can lead to more parid habitat loss.
Facts about the Olive Sea Snake
- They are one of the most commonly found species of sea snake in the Great Barrier Reef
- They have been known to confuse divers for females during mating season
- They rarely venture into open waters unless they are looking for a mate
- Their biggest threat is fishing nets and trawlers
- Their venom is extremely powerful and breaks down their prey from the inside
FAQs
Are olive sea snakes venomous?
Yes, the venom of the olive sea snake is very powerful. It is known to break down its prey from the inside out, making it easier for them to digest.
Where do olive sea snakes live?
Olive sea snakes inhabit coral reefs in the Indo-Pacific region. They are commonly found in the Coral Sea and reefs such as the Great Barrier Reef.
Are olive sea snakes aggressive?
Yes, they are considered to be very aggressive when hunting. However, they rarely show aggression toward humans and larger animals. But don’t test this out, as if provoked they can be very aggressive.
Are olive sea snakes endangered?
Generally, the olive sea snake is an animal of ‘Least Concern’ on the IUCN Red List. Although the population is thought to have decreased slightly, they are far from endangered.