Colorful and clever, worms are much more than bait. Many of the most striking examples of worms are difficult to track down.

Predators relish the worms’ succulent, segmented bodies, so it’s essential for the animals to keep a low profile. To survive, most species spend their lives inside crevices or beneath the sand, venturing out only after dark. On a recent visit to Dominica, our local dive guide, Tony, took us on a hunt for a scientifically undescribed species of Onuphidae worm, known only from photographs. We headed for the shallows and searched along the surge line until we saw what we were looking for: three antennae no larger than straight pins, sticking out of the sand. Other than showing off its gaudy purple, orange and white antennae, the worm didn’t cooperate until presented with the carcass of a lionfish — minus the fillet. Tony skewered a chunk of the fish on a metal rod, and at the first whiff, the worm shot out of the sand like a cobra. Although he went for the bait, the worm extended out of the sand only a bit. Nonetheless, it was enough for us to catch a glimpse of 3 or 4 inches of its outlandish body, spangled with multihued lobes and filaments, before it disappeared.