Thousands of 'penis fish' wash up on Argentine beach

Spoonworms, also known as penis fish, have been stranded along beaches in Argentina after a storm, attracting fishermen to collect them for use as bait .

Dead sea worms on Multillar beach. (Photo: Jam Press).

Countless sea worms, scientifically known as Urechis unicinctus, were washed ashore on Multillar Beach in northern Rio Grande, Argentina, after a major storm on the afternoon of July 17, according to the Mail . Local fishermen flocked to the beach to collect the worms because they are excellent bait, especially when fishing for black sea bass.

This is not an uncommon phenomenon in Argentina. They have previously washed up on the southern coast of the country during stormy weather. In 2019, the creatures also covered a beach in the US state of California.

About 25cm long, sea worms usually burrow into the sand, but storms and ocean swells can easily push them out of their hiding places and onto land. They dig U-shaped burrows in the seafloor, allowing other animals to burrow into them. Fossil evidence suggests that sea worms have been on Earth for 300 million years. Individuals can live up to 25 years, feeding mainly on bacteria and plankton. They are preyed upon by larger fish, sharks, seagulls, otters and even humans.

"U. unicinctus is completely harmless to humans because it has no teeth and feels very pleasant to the touch. Moreover, in Asian countries, it is also used as food, can be eaten raw or cooked in many different ways," said Russian researcher Igor Adameyko.

People in Korea, Japan, and China often eat sea worms raw with salt and sesame oil. They are considered a nutritious food because of their high concentration of amino acids. Their taste is very mild and similar to oysters.