Horny sea snakes attacking divers after mistaking them for potential sexual partners

Sea snakes that bite divers are in fact just mistaking them for potential sexual partners, a study has revealed.

Experts from Macquarie University in Australia concluded that the creatures charging at, biting, and coiling around divers – which is commonly reported – may represent misdirected courtship behaviours, rather than an actual attack.

Sea snakes are considered to be highly venomous, often more so than snakes on land.

But bites to humans that see any toxin injected are rare.

For example, the death of an Australian fisherman in 2018 was reportedly the first sea snake fatality recorded since one of the creatures killed a pearl diver in 1935.



Research suggests male Olive sea snakes are more likely to attack humans during mating season and flick their tongues and coil their legs around a limb – which are behaviours also associated with courtship

In the rare event that venom is delivered, the bite itself is usually painless but symptoms can include muscular pain, weakness, vomiting and even paralysis.

In the paper, the researchers wrote: “Scuba-divers on tropical coral-reefs often report unprovoked “attacks” by highly venomous olive sea snakes.

“Snakes swim directly towards divers, sometimes wrapping coils around the diver’s limbs and biting.



The misdirected courtship behaviour could be a reason why scuba divers are subject to unprovoked attacks by sea snakes
The misdirected courtship behaviour could be a reason why scuba divers are subject to unprovoked attacks by sea snakes

“Based on a focal animal observation study of free-ranging Olive sea snakes in the southern Great Barrier Reef, we suggest that these “attacks” are misdirected courtship responses.”

In the study, data collected by biologist Tim Lynch was analysed by the researchers.

Dr Lynch recorded the data in 1994 and 1995 when he was a diver on the Great Barrier Reef.

The team noted that out of 158 encounters with the olive sea snake, Aipysurus laevis, the serpents approached Dr Lynch 47 per cent of the time.



Many attacks by sea snakes have been reported by divers over the years
Many attacks by sea snakes have been reported by divers over the years

Approaches typically saw the creatures flicking their tongues at the biologist, and were found to occur more often during the mating season which runs from May until August.

This was found to be more common among male sea snakes than females.

Interactions which saw the sea snakes ‘rapidly charging’ at Dr Lynch occurred 13 times — all of which took place during the mating season.

Events in which the males charged at the biologist were always in the wake of them unsuccessfully chasing a female sea snake, or having an interaction with a rival male.

In contrast, female sea snakes charged Dr Lynch either following pursuit by males, or after having first lost sight of, and then re-approached, the diving researcher.

On three occasions, male sea snakes were seen coiling around one of Dr Lynch’s fins — a behaviour that is normally observed during the animal’s courtship rituals.

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