The Terrifying Bobbit Worm

bobbit worm

Do you remember the classic 1990 monster movie, Tremors, starring Kevin Bacon? If not, here is a very short recap. A town is being terrorised by enormous burrowing worms that drags them into the dirt and eats them, and Kevin Bacon, along with his on screen buddies, must find a way to stop them and save the town. Many fantasy movie enthusiasts believed Tremors was simply a rip off of the 1984 sci-fi classic, Dune, which also contained giant worm like creatures that would drag people to their doom.

Just like so many other movies, books, and ancient fables, the creators of the Graboids and Sandworms have drawn their inspiration from nature, and the real life version may not be as large as their Hollywood portrayals, but they are in no way less sinister.

It is time to meet the creature of your nightmares, the Bobbit Worm.

What is a Bobbit Worm?

Scientifically known as Eunice aphroditois, the Bobbit worm is a predatory segmented worm that can grow to a maximum length of three metres. They can be found throughout tropical waters worldwide, however they tend to prefer muddy, soft sea beds such as those found throughout parts of Indonesia, Papua New Guinea, and the Philippines.

They are part of a little known, but huge class of marine creatures called Polychaete (or more commonly ‘bristle worm’), which is made up of over 10,000 recorded species. You may have never heard of them before, but you might have seen them. They are the creepy worms that are often attracted to your torch during a night dive.

What does a Bobbit Worm Look Like?

It is extremely rare to see the full Bobbit worm out of its burrow.

If you are lucky enough to find one, you will see five antennae and an enormous set of jaws connected to the top of a segmented body. Their colour normally ranges from dark brown, to gold-red, however if you shine a flashlight on them, they will reflect and amazing rainbow like colouration. The fourth segment from the top is either white, or paler than the rest.

Like almost all other polychaete, Bobbit worms are covered in harpoon-like bristles that will cause severe irritation, and possibly even permanent localised numbness if handled. These bristles have two purposes; to help them grip whist crawling across the substrate, and as a defence mechanism if something were to attack it.

bobbit-worm

What does a Bobbit Worm Eat?

Bobbit worms are ambush predators that are not particularly picky about what they eat, although they tend to prefer soft bodied animals such as fish or cephalopods.

Their five antennae are sophisticated sensors that can detect the slightest movement in the water above them. When something gets within range, they will strike by shooting upwards and clamping  their ferocious jaws shut. This attack takes place is less time than it takes for you to blink, and the jaws can shut with such immense power that the helpless prey can be sliced in half!

Those animals large enough to survive the initial strike will be injected with venom that will stun them, allowing the Bobbit worm to drag them into its burrow and eat them. Like some species of snake, Bobbit worms can eat and digest prey much larger than themselves.

Where does the Name “Bobbit Worm” Come From?

Back in the early 1990’s, there was an incident in the USA that made world news. A woman named Lorena Bobbitt was suffering from an abusive relationship, and after one particularly abusive night, she took a kitchen knife and cut her husband’s penis off while he was sleeping. The name ‘Bobbit Worm’ was first referenced in a 1996 creature guide for the Indo-Pacific region, as the author was comparing the scissor like jaws to the Lorena Bobbitt case.

This naming had resulted in a common myth that the female worms will cut the penis off the male worm after mating, and then feeds it to her young. There is no truth whatsoever to this myth, as Bobbit worms (or any other polychaete) don’t have penises or vaginas. They breed via ‘broadcast spawning’ where the males and females will release sperm and eggs into the water column where the eggs will become fertilised, before drifting off with the current. Like all other species that breed via broadcast spawning, Bobbit worms do not care for their young, and will probably never encounter their offspring.

Bobbit Worms in Aquaria

As you can probably imagine, there is little demand for an enormous predatory worm in the aquarium industry, however, that doesn’t mean that they don’t occasionally ending up in peoples tanks.

As a juvenile, Bobbit worms are tiny, and they will spend a lot of time hiding amongst rock and coral for protection. Because most rocks and corals sold for aquariums are collected from real coral reefs, there have been a few instances of bobbit worms being collected by accident, and subsequently devastating the tanks intended residents.

In 2009, staff at an aquarium in Newquay, Cornwall, repeatedly found that fish were missing and corals were damaged in one of their displays. After taking apart the display, the staff found a one metre bobbit worm living in the sand. The worm was nicknamed ‘Barry’ and was given its own display at the aquarium.

Where can I Dive with Bobbit Worms?

Originally discovered off the coast of Sri Lanka, Bobbit worms are now known to be found throughout much of the Indo-Pacific region. Although they can be found living on coral reefs, they tend to prefer sandy/mucky/gravel areas, as it is much easier for them to burrow into the substrate.

Your best bet for finding them is to head to muck diving meccas such as Lembeh in North Sulawesi, Tulamben in Bali, or Anilao in the Philippines. As bobbit worms are nocturnal, you will probably need to do some night diving in order to find one (luckily night diving and muck diving is an amazing combination!). As long as food is available, they will stick around in the same area, so as always, it is best to speak to your dive guide and ask if there have been any recent sightings.

‘The Terrifying Bobbit Worm’ was written by Mike

Photo credits: AllyMcDowell & DiveMeCressi