Sea cucumbers, relatives of sea stars and sea urchins, come in quite a variety of shapes and sizes. Those common to my neck of the woods are typically a bit larger than a very good-sized banana. I’ve also seen extremely long sea cucumbers in Hawaii, and the Caribbean. But I’ve never seen a monster like the one in today’s photo until I made a dive on Rainbow Reef off Vanua Levu in the Republic of Fiji. There seems to be no common name for this species, which is known scientifically as Stichopus pseudohorrens (stick-o-puss suud-o-hore-ens). This particular individual was over 24 inches (61 cm) long and at least 6 inches (15 cm) in diameter. Covered with large conical protrusions, it really looked like some sort of an alien that had landed in the ocean.
Sea cucumbers play a major role in cleaning sediments on the sea floor. Like earthworms on land, they consume sediments and digest out the organic material they contain. Their poop is essentially clean sand on the reef. Some species of sea cucumber produce little strings of sand encased in mucus that are very noticeable on the bottom, until the outer sheath degrades and the sand poop crumbles onto the bottom.
Unfortunately, sea cucumbers are considered delicacies in many parts of the world and are being harvested at unsustainable rates in many places. There is not enough data on the abundance and distribution of Stichopus pseudohorrens to determine the status of this species. The understanding of it’s distribution is so poor, that Fiji isn’t even mentioned as being part of its range. But clearly I saw this beast there, and had its identity confirmed by a sea cucumber expert in Florida.
There is still so much to learn so that we can protect the Earth’s biodiversity on which we all depend.
This photo was taken with a Canon EF8-15 mm f/4 lens zoomed to 15 mm on a Canon EOS 5D Mk. III in an Ikelite underwater housing. Lighting was provided by twin Ikelite DS161 strobes in eTTL exposure mode. The exposure was set to 1/60 sec at f/9.5 and ISO 200.