The sea cucumber, a relative of the starfish and sea urchin, isn’t much more than a blob creeping across the ocean floor on tentacle-feet, munching on algae and plankton. The most interesting thing about the animal may be that some species defend themselves by ejecting respiratory tissues through the anus in the direction of the attacker. But here on the Yucatán Peninsula, the un-charismatic sea cucumber has become so sought-after that the local …