The fastest worm in the ocean?

Sightings of this worm have been around for about a decade in the Lembeh Strait. We’ve been getting some photos of it this year, but we thought we would go step further and try to explore the behaviour of this interesting creature. Simon has given it the common name of the Bullet Worm, read on to find why!

Initial observations of the forward facing eyes indicated to me that it was a visual predator, and of course as it seems to stay in its burrow it must logically ambush its chosen prey like like a Bobbit worm. Interestingly the Bobbit has no noticeable eyes, but does find prey by being attracted to their shadow passing over the sand.

Luckily we found a site with around 15 of the worms in close proximity to each other (I’m sure there were more but I figured 15 is enough!).  Still photographs are relatively easy to capture, as long as you do not shine too strong of a light onto the worm.

Learning more:

Spending several hours around the bullet worms has led to a greater understanding of how the worm hunts, and my initial speculations were confirmed when one of the worms came about 60cm / 2 feet out of the burrow to investigate my camera as I swam by!

Eventually I found I was able to entice the worm out of the hole by wiggling my fingers above the worm, however when I was trying this I had no idea about how the worm fed! With hindsight this probably isn’t a good idea.

Moving forward to another dive and attempt to see what is going on and feeling somewhat disenchanted with the lack of success on the previous two dives. Whilst swimming over to the worm I noticed that some cardinal fish were attracted to my lights on this occasion, so I set up and waited.  The result was incredible and one of the most surprising things I have seen whilst diving.  The clip below was shot at 4x slower than realtime, and then slowed again in the computer another 4x. The whole hunting process took less than 1/16th of a second, which puts it up there with the Strike Speed of the Mantis Shrimp, hence I crown this the bullet worm, the fastest worm in the Ocean.

The Bullet Worm:

I have not seen any literature describing this worm or any other using a harpoon to hunt, please do let us know if you find any further information on this.

There is still my initial observation of the worm exiting the burrow a la Bobbit Worm, which could possibly mean that the whole worm can ascend up the water column; before striking with the harpoon appendage. This is definitely a creature to put on you underwater nightmare list!

Gear used:

Olympus TG-6 with Backscatter MF-2 Flash.

Eupolyodontes sp. has a strong dislike of light, so to capture these clips I had to use very low power settings on my FIX NEO lights, these lights have the lowest power settings of any light I’ve ever used, and are also my recommended light as a focus light for Blackwater Diving.

I paired this low powered light with a Nauticam FX3 housing for a SONY FX3 low light camera which has a native lowlight iso of 12800. 90mm lens. Special thanks to Ryan from ReefPhoto / Nauticam for helping me get the correct setup for this mini-shoot.

About Us:

Simon is one of the owners of NAD-Lembeh, when not in lembeh you can find him diving or filming in other locations. You can follow him on Instagram @Scuba.Simon and NAD-Lembeh @nadlembeh

NAD-Lembeh is a small photography focussed dive resort in the Lembeh Strait. Owned by Simon and Zee Buxton, we still adore diving in Lembeh and luckily get to do 100’s of dives a year in the strait, taking pictures and making movies.

Categories: Critters