A Jet-Black, Bioluminescent ‘Football Fish’ Washed Up on a California Beach

A rare deep-sea fish with teeth resembling tiny shards of glass, a football-shaped body and a long bioluminescent stalk on the top of its head washed ashore in California this week. The sea creature was later identified as a female Pacific footballfish (Himantolophus sagamius), reports Faith E. Pinho for the Los Angeles Times.

Beachgoer Ben Estes stumbled upon the rare find on the shores of Crystal Cove State Park's Marine Protected Area in Newport Beach. The species is one of more than 200 species of anglerfish on the planet found at depths of 3,000 feet, reports Amanda Jackson for CNN.

"I don't know if he understood the implications of what he found," Jessica Roame, an education coordinator at Davey's Locker Sportfishing & Whale Watching, tells the Los Angeles Times. "It happens when you're walking along—you find dead things here and there that just shouldn't be on the beach. The thing about this was that it was almost perfectly intact. Where did it come from that deep below?"

Light can't penetrate through the water at those depths, and these fish live in total darkness. Encounters with other fish and prey are infrequent, so the footballfish evolved to feed on whatever fits in their 18-inch mouths. To lure prey in the dark, the anglerfish uses an extended fin that resembles a fishing rod with a glowing bulb called an esca at the end. The esca gets its glow from tiny bacteria called Photobacterium, which live within the pores of the anglerfish's esca.

Based on the size of the footballfish and the protruding appendage on the top of its head, Crystal Cove State Park officials say the fish is female. Only female footballfish have the long bioluminescent appendage used to lure other fish toward its mouth. Females can also reach a maximum size of 24 inches, while males grow only to be one inch long, Crystal Cove State Park officials explain in a Facebook post. Males are "sexual parasites" that will latch onto a female and eventually fuse until there is nothing left of their bodies except their testes for reproduction.

How the anglerfish ended up washing ashore on the California beach is unknown. The California Department of Fish and Wildlife took the Pacific footballfish while it's sorted out where the fish will go, reports Samantha Lock for Newsweek. California State Park officials connected with Los Angeles County's Natural History Museum in hopes that the fish can be added to their collection of ocean species. The museum already has three others anglerfish in their collection, but only one is from California. None are in pristine condition like the one recently washed ashore, John Ugoretz of the California Department of Fish and Game explains to the Guardian's Gabrielle Canon.

"Seeing this strange and fascinating fish is a testament to the diversity of marine life lurking below the water's surface in California's MPAs and as scientists continue to learn more about these deep-sea creatures. It's important to reflect on how much is still to be learned from our wonderful ocean," Crystal Cove State Park write in their Facebook post.

Elizabeth Gamillo | | READ MORE

Elizabeth Gamillo is a daily correspondent for Smithsonian and a science journalist based in Milwaukee, Wisconsin. She has written for Science magazine as their 2018 AAAS Diverse Voices in Science Journalism Intern.