Bizarre Deep-Sea Fish Keep Washing Up in California and Scientists Don't Know Why

Several bizarre-looking deep-sea fish have mysteriously washed up on California's beaches this year, leaving marine biologists baffled.

The latest Pacific footballfish to be washed ashore in the state was spotted near Encinitas last Friday, according to the Scripps Institution of Oceanography.

A surfer found the strange fish dead on Swami's Beach and alerted lifeguards, who then notified scientists. Scripps scientist Ben Frable then collected the unusual animal for research and preservation purposes.

The ghoulish fish is black, almost spherical in shape and has razor-sharp teeth. Its skin is covered in little spines and it also has a strange appendage protruding from its head with multiple branches—a bioluminescent lure used to attract prey in the inky blackness of the deep ocean.

The specimen found on Swami's Beach is a mature female measuring nearly 13 inches in length and weighing around 5.5 pounds.

Pacific footballfish are very rarely seen given they are typically found at depths of between 650 and 2,600 feet, according to Frable. Only 31 known specimens have ever been collected worldwide and it has never been seen in the wild, so scientists know very little about the species.

Despite the fact the fish are rarely seen, three of them have washed up on California's beaches this year—including one that was spotted last month at Black's Beach, north of San Diego. Unfortunately, scientists weren't notified in time to collect it and the fish may have been washed away.

The three sightings this year doubles the total number of sightings on record in California, the Los Angeles Times reported.

"It is very strange, and it's the talk of the town among us California ichthyologists"—zoologists who study fish—Bill Ludt, assistant curator of ichthyology at the Los Angeles County Natural History Museum, which has four specimens in its collection, told the Times.

Regarding the series of recent sightings, Ludt said: "It's hard to jump to any conclusions about why this is happening... That's the million-dollar question right now."

Ludt's comments echo those from the Scripps Institution, which said in a series of tweets that experts don't have any evidence right now to explain why several of these deep-sea fish have washed ashore recently.

Scientists are "interested in learning more about the specimens that have been collected, as well as any new ones that might wash up," the tweet said.

The specimens that were collected recently appeared to be in surprisingly good condition and don't appear to have any indications that they experienced trauma, such as an attack or poisoning.

After collecting the latest specimen, Frable took X-rays and collected tissue samples for genetic analysis.

Pacific footballfish are among the largest of the roughly 170 species of anglerfish known to science, measuring up to around 15 inches in length. Males are typically much smaller than females.

Following the recent find, Scripps asked anyone who comes across an unusual fish or other marine animal to leave it alone and contact the institution or notify a lifeguard.

"Rare specimens like this #footballfish are incredibly valuable to the marine science community," Scripps said in a tweet.

Frable told Newsweek that scientists had conducted an examination of the fish's stomach to see what it might have eaten, given that almost nothing is known about the diet of this species.

But unfortunately, the stomach was empty except for a lot of sand that had entered the animal's body when it washed up onto the beach.

The scientist said the recent beachings are either coincidental or somehow related to the biology of these fish. Large footballfish have been known primarily from beaching for almost 200 years.

"The first anglerfish ever described by science was a footballfish found on a beach in Greenland in 1833," Frable said. "Additionally, many of the beachings around the world occur in the winter months, so there could be something this time of year. With so few individuals and so little known about the biology of anglerfishes in general, we cannot make a determination."

He said: "We can say this is likely not related to the recent oil spill up north, any sonic booms or other freak occurrences, as in these cases we see many marine organisms washing ashore, not just a couple of fish."

Update 12/20/21, 8:40 a.m. ET: This article was updated to include additional comments from Ben Frable.