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Questions arise surrounding strange marine animal’s identity

Suzanne Guldimann, Freelance Reporter
8:59 am PDT July 12, 2017

What appears to be a dead sea hare, a species of marine gastropod, caused a stir on the internet after the beachgoer who found the remains of the animal at Leo Carrillo Beach posted photos of it to the social media site Reddit.

The photo of the creature can be viewed at imgur.com/P6TJaw4.

It’s not the first time a Malibu sea creature has generated headlines. In 2010 a 10-foot-long sea serpent-like oar fish turned up at Malibu Colony. A 40-foot-long dead fin whale made headlines in 2012 when it washed ashore at Point Dume, and in the 1950s, the remains of a giant squid were reportedly fished out of the water off Paradise Cove.  

This time, tabloids from as far away as Britain, India and Russia described the find as “bizarre,” “baffling” and “shocking,” despite the fact that another Reddit user swiftly identified the dead marine organism as something much less exotic than a sea monster.

Reddit community member pacifickestrel responded to creature finder xxviiparadise’s request for an ID in the “whatisthisthing” group on Reddit.  

“I believe this is a dead sea hare,” pacifickestrel wrote. “As a marine biologist, I’ve seen plenty. They start to look all sorts of weird the longer they’ve been dead, but that big muscular foot running along the side there is pretty characteristic.”

A live black sea hare, which is about the size of a football, is pictured in August 2016. The mysterious Malibu sea creature that has been generating headlines as of late is believed by some to be a sea hare. Suzanne Guldimann/22nd Century Media

Mike Schaadt, the director of the Cabrillo Marine Aquarium, did not see the internet sensation but confirmed that a decomposing sea hare seemed a reasonable conclusion.

“Sea hares can start to look really strange after they die,” Schaadt told the Malibu Surfside News. 

He explained that the decomposition process can transform almost any sizable marine organism into something that appears bizarre and baffling at first glance.

Schaadt has seen his share of strange finds. 

“We had a thornback ray recently,” he said. “But it had decomposed so much it was hard to tell what it was.”

Schaadt explained that sea hares are gastropods not unlike like garden snails. However, their shell is small and entirely internal. 

The large foot that is the “pod” part of the word “gastropod” consists of dense muscle tissue that decays at a slower rate than the sea hare’s softer organs.

There are two common local species of sea hare in the Malibu area: the California brown sea hare and the black sea hare. 

Judging from the Reddit poster’s description of the size and weight of the creature found at Leo Carrillo — six inches across and around seven pounds, odds are good that it could be a black sea hare. 

“The black sea hare gets a lot bigger,” Schaadt said. 

Brown sea hares (Aplysia California) can grow to be 16 inches long from nose to tail and weigh up to five pounds. The black sea hare, Aplysia vaccaria, is actually the world’s largest known gastropod, making it a true sea monster in a modest way. It can grow to be more than three-feet long and weigh as much as 30 pounds. 

Schaadt explained that both species get their name from their protruding rhinophores — scent organs that resemble the ears of a rabbit.

Sea hares, like their land snail cousins, are vegetarians that use a rasp-like tongue, called a radula, to eat seaweed and other algae. That diet makes adults inedible to many ocean predators. The black sea hare relies on its disagreeable taste and smell to deter predators, but the smaller brown sea hare can squirt out an acrid purple dye to discourage anything willing to take a bite.

Despite being unpalatable, the attrition rate for sea hares is high. 

“Each can produce hundreds of thousands of eggs,” Schaadt said. “But only one or two will survive to become reproductive adults. The larvae are planktonic, they don’t settle down right away, and most get eaten by other species. Otherwise we would be chin-deep in sea hares.”

The Reddit user who posted the mystery photo was fortunate to receive a response from someone with a marine biology background, but Schaadt explained there is an easier and more direct way to get an ID on marine organism.

“We have a form on our website where you can ask a biologist directly,” Schaadt said. “What you need is a trusted local source for information. We have that here.”

The Cabrillo aquarium features a wide range of native marine life on exhibit. Classes and nature walks offer an interactive look at the beach and the intertidal zone. Guided tide pool walks will resume in the fall when the year’s lowest daytime tides occur.

Schaadt said the story of the Leo Carrillo mystery creature is a great opportunity to remind beachgoers to use care while exploring tide pools. He explained that taking a photo from a safe distance is a better option than handling tide pool life and added that many species are fragile and won’t survive being moved or removed. 

“It’s possible to love tide pools to death,” he said.  

The Cabrillo Aquarium’s marine biology team is happy to help ID marine life at www.cabrillomarineaquar
ium.org/research/ask-biol
ogist.asp. The aquarium, located at 3720 Stephen M. White Drive in San Pedro, is open seven days a week. For more information, call (310) 548-7562.