Admit it, and it’s not an everyday picture: a beach in California is flooded by thousands of spoonworms with the scientific name Urechis unicinctus. They are popularly known as ‘penis fish’.
The resemblance is, therefore very striking. The worms in question usually hide underwater, deeply nestled in mud or sand. Due to a massive storm, they have now surfaced on Drakes Beach, a deserted beach about fifty kilometers from San Francisco.
“I’ve already heard the wildest theories of beachgoers,” says biologist Ivan Parr. “Some even thought that a ship with bratwurst had sunk.” But for the sake of clarity, that is not the case. “This example shows that it is not a wise decision to build a house on sand,” says Parr. “Heavy storms can completely change the intertidal area (the area that remains above the water at low tide and underwater at high tide; e.d.). What is normally hidden is then left behind on the beach.”
The scrub worm can live up to 25 years and uses a trunk to eat and move on. The species love bacteria, plankton, and other small particles. The strange creatures have so far been mainly noticed in California, just think of places like Pajaro Dunes, Moss Landing, Bodega Bay, and Pillar Point Harbor.
Penis fishes are estimated to have been around for 300 million years. In addition to otters, flatfish, rays, sharks, and seagulls, humans also pose a threat to them. In South Korea, they are eaten as a true delicacy.