The Chromodoris nudibranch first named for the University of California in 1901 had vanished for decades from its native habitat in Southern California, until one was spotted off Catalina Island in 2003. Now, steady sightings have led marine biologists to believe it is making a comeback, for reasons yet to be determined.
“It started disappearing form California in the 1970s and was completely gone by 1984,” said Jeff Goddard, a project scientist at the Marine Science Institute at UC Santa Barbara, whose findings were published in the journal Marine Biology. “There are no records of it for 20 years and then a diver at Catalina found it in one or two places.”
It wasn't for lack of trying. “People used to be able to go snorkeling and diving off La Jolla and see tens of these," Goddard said. One log showed 65 in a single day. “Down there the summer, low tides can start before dawn. These people would go out before 3 in the morning with Coleman lanterns, just because they liked them.”
The slug, which grows to about 3 or 4 inches long, once was abundant in tide pools on the mainland and in the Channel Islands. It was also found at locales including an artificial reef made of old streetcars off Redondo Beach, and on pilings in Newport Beach. Populations of the species also thrived - without the apparent recent collapse - in Mexico.
When the colorful marine gastropod mollusk was "discovered" in 1901, it was named "universitas" for ‘‘colors … of the University of California’’ and also because it was ‘‘collected
at San Pedro by the naturalists of the University of California Marine Laboratory,’’ according to the report.
But the zoologists who named it, Theodore and Wilmette Cockerell, realized it had been described in 1879 and had been given the californiensis name.
Under either name, Goddard said, “It still can be thought of as a namesake for the University and the state.”
Why Felimare californiensis disappeared from local waters, even as marine biologists and divers sought it, remains a mystery, Goddard said. Its demise is not likely due to climate change or cyclical weather cycles, he said.
“We don’t know the cause but when I consider all the evidence – and this is just a hypothesis – I think it is pollution, who knows of what sort, that affected its sponge prey,” Goddard said.
That pollution could have affected the life span of the particular sponge hunted by the slug, or the blue-green algae that live cooperatively on the sponge, Goddard said.
The species could be a candidate for protection under the Endangered Species Act, though it is unlikely to garner the public support accorded such charismatic megafauna as the polar bear, or even the lowly but valuable white abalone.
Then again, the banana slug, mascot of UC Santa Cruz (Goddard's alma mater), has quite a following.