Marine worm Eunice Roussaie - aka the St. Lucia Thing

Close Encounter with the St. Lucia Thing

Back in the late 1980’s to early 1990’s, St. Lucia’s has a somewhat legendary resident sea monster called the Thing. Capturing a few images not only disproved it as some mythological beast, but also helped reveal it as a potential new species of marine invertebrate.

There are a lot of things still waiting to be discovered in the underwater world. Divers make new discoveries all the time, but often don’t realize the importance of what they have discovered. But sometimes they do, and when they report their findings, new behaviors and sometimes entirely new species are added to the scientific record. Take, for example a find I had made way back in 1994 during a visit on the island of St. Lucia, which is located mid way down the Caribbean’s Windward Island chain. It was there that I heard about a mysterious reef creature locals called “The Thing.” I still talk about this experience today.

St. Lucia's most recognizable landmark are the Piton’s twin volcanic peaks standing over Soufrière Bay. The tallest is Gros Piton with an elevation of  2,530 ft, with Petit Piton coming in at 2,438 ft high.
St. Lucia’s most recognizable landmark are the Piton’s twin volcanic peaks standing over Soufrière Bay. The tallest is Gros Piton with an elevation of 2,530 ft, with Petit Piton coming in at 2,438 ft high.

For some time, the dive operation at the resort Anse Chastanet, as well as a local marine biologist on the island, had heard reports of a worm-like creature that was said to be ten feet long and as thick as a human arm, There were supposedly eyewitness accounts and one very grainy picture, but no real explanation of what this creature might be. In my travels, I sometimes hear these kinds of things. I enjoy a good island tale as much as the next guy, but this one seemed especially improbable.

For such a large reef-dwelling creature, it seemed extremely elusive—a bit like the Loch Ness Monster. The one thing everyone was certain of was that the only time it could be found was on the darkest nights. And it was also said to be highly reactive to dive lights, supporting the idea that it was especially sensitive to any kind of light. In one divemaster’s words, “Man, light makes it snap back into its hole faster than a rubber band.” Beyond that, the island’s resident marine biologist couldn’t offer a clue as to what it might be and remained baffled to the point of listing it as “un-described.”

Never one to pass up a good mystery, I planned a few night dives in hopes of determining if this enigmatic creature was fact or fiction. The second night of my stay looked the most promising, as it was on the beginning of the new moon. It would be truly black underwater.

Working up and down the sloping face of the reef between depths of 40 and 80 feet, I cupped my hand lightly over the lens of my dive light so as not to cast too much light on the bottom. I started to wonder if I was on a fool’s errand. Three quarters into the dive having not seen anything remotely resembling this reef version of Ness, I started imagining the resort’s dive staff at the bar having a good laugh about what I was doing. Then just as I was getting close to calling the dive, something moved in slow serpentine fashion amongst the coral.  Could this be it? Have I actually found the fabled Anse Chastanet Thing!

To prove it really did exist, I need to get a picture of it. To my surprise, it didn’t recoil from the sudden flash from my strobes. Maybe it was sick, I don’t know. Compared to what the divemaster’s had described, it was a fairly small specimen – about four feet in length and as thick as my wrist. While no giant, it was far bigger than any species of marine worm I had ever seen. And yes, it was most defiantly some kind of worm.

Excited by my discovery, I passed few images on to my good friend Paul Humann. He and Ned Deloach were working on the second revision of their Reef Creature Identification book for the tropical Atlantic and Caribbean, so I figured he would be able to find someone who might possibly identify it. As it turned out, this was a new species never before identified. The best any of the scientists were able to do was determine it belongs to the Phylum Annelida, meaning little rings, which is applied to most segmented worms. To cite Paul’s book, “Common earthworms, as well as many marine worms are members of this Phylum.”

The bearded or more commonly known bristle fireworm (Hermodice carunculata) seldom get any larger than 4 to 5 inches in length.
The bearded or more commonly known bristle fireworm (Hermodice carunculata) seldom get any larger than 4 to 5 inches in length.

This group’s most distinguishing characteristic is that their body is divided into a repetitive sequence of round segments. The marine variety is known as Polychaetes. Examples would include the bearded or bristle fireworm (Hermodice carunculata). This creature’s body segments are a dark to reddish brown with a pearl-like tint, separated by deep creases with large cirri (appendages used for locomotion) and feather shape gills that are soft to the touch (yes, I touched one) running down both sides, sort of like a centipede.

Long brisile Eunice (Eunice longisetis), Palm Beach Florida.
Long brisile Eunice (Eunice longisetis), Palm Beach Florida.

Much closer still is the long brisile Eunice (Eunice longisetis). Although they bare a strong resemblance to “The Thing”, the long brisile Eunice only achieves a maximum length of 18 inches. And like The Thing, they are listed in Humann/Deloach’s Reef Creature Identification book as “Uncommon Florida; also Bermuda.” This one (above) was photographed during a night dive at Palm Beach, Florida’s Blue Heron Bridge.

The identification of “The Thing” is tentative, as more taxonomic research needs to be done once viable specimens or tissue samples are obtained. Problem is not only are they nocturnal, but they are also still considered extremely rare, with only a handful sightings in Bonaire, Curacao, and the Bahamas, in addition to St. Lucia. Still now, and for the moment, all anyone can say is that it belongs to the Family of elongated worms Eunicidae, giving rise to its Genies species name: Eunice roussaei. And that it inhabits deep recesses in the reef and can grow up to 6 feet in length. The last part is only speculative, since scientists are not sure how big they really get. 

Marine worm Eunice Roussaie - aka the  St. Lucia Thing
Eunice Roussaie – aka the St. Lucia Thing.

Who knows? There may be actually be a 15-foot long monster out there somewhere on the reef.

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