A strong storm left a very unusual sight on one California beach this week --- thousands of phallic-looking marine animals known as "penis fish."
The event took place on Drakes Beach in the Bay Area, where Bay Nature Magazine noted that a strong storm brought waves that wiped away the top layer of sand. This left thousands of the fat innkeeper worms --- which normally live in burrows beneath the surface --- exposed on the surface of the sand. The pink or flesh-toned animals are long and tubelike, bearing a striking resemblance to part of the male anatomy.
The magazine took to Twitter to share a picture of the beach littered with the peculiar-looking animals, showing piles of the long pink worms and the flocks of birds that appeared to be eating them.
The worms are an incredibly rare sight, CNN reported. Because they have a number of natural predators, the worms remain under the sand's surface for almost their entire lives, feeding and breeding under the safety and protection of the sand. It's a smart approach, the report added, as biologists have found some of the fat innkeeper worms that are believed to be 25-years-old. The species itself has been around for 300 million years.
But taking cover under the sand also leaves the "penis fish" vulnerable when especially strong storms sweep through, noted biologist Ivan Parr.
"We're seeing the risk of building your home out of sand," Parr wrote in Bay Nature (via CNN).
"Strong storms -- especially during El Niño years -- are perfectly capable of laying siege to the intertidal zone, breaking apart the sediment, and leaving their contents stranded on the shore."The worms are normally between six and nine inches long, but can sometimes grow up to 19 inches, the NOAA reported. They capture food by circulating water through their U-shaped burrows, trapping it in a layer of mucus and then eating the entire thing. The worm gets its actual name of "innkeeper" from the fact that a number of other fish and small animals take cover in these burrows for safety, allowing them to share their home. The report noted that there were other mass strandings of the fat innkeeper worms in 2010 and 2016, both during El Nino weather events. It's not clear what effect this has on the species as a whole, as CNN noted that it's difficult for scientists to study the size of their populations due to their hidden lives.