In what will be a familiar story to many in Oregon, a native of California has taken up residence here, likely driven from the Golden State by the rising tide of rent and fear of the tech bubble bursting.

Well, maybe it was just a normal rising tide and regular bubbles bursting.

This new Oregonian is not a hoodie-clad ex-app developer or an artist priced out of a San Francisco cohabitational live/work space. This transplant is roughly potato-sized, eats algae and is thought to have made the move north during its larval stage, probably stowed away in the bilge pump of a fishing boat.

The California sea hare -- a sea slug, which is rarely, if ever, observed north of the state line -- was discovered recently settling into its digs in a seawater holding tank at the Oregon Coast Aquarium in Newport.

"I'm originally from Monterey, (California), where sea hares are a common sight in bays, estuaries and rocky intertidal areas," Anna Welsh, an aquarist intern who discovered the creature while cleaning the tank, said in a statement. "But I was definitely surprised to see it here, outside of its range."

The sea hare, usually found from the northern coast of Mexico to the Oregon border, is a rarity this far north, officials said. Only a few records exist of sea hares this far up the coast and Yaquina Bay, where the aquarium is located, seems to be the farthest north one has ever been spotted.

"I have been diving, snorkeling, seining, and fishing here on the Oregon Coast for 20 years and have never seen one," said Jim Burke, the Aquarium's Director of Animal Husbandry. "My thought is that it arrived here in its free-floating larval state, most likely as a hitchhiker inside a boat's bilge or fish hold."

That would mean that the California transplant would have had to make a pretty miraculous journey. After, theoretically, being released from whatever boat it rode in on in Yaquina Bay, the tiny larval slug would have been sucked up by one of the aquarium's intake pumps. Then, it would have had to pass through a 6-millimeter-gauge filter where it would have found itself floating peacefully in the holding take, free of predators amongst the waving kelp fronds and bivalves that inhabit the holding area.

Sea hares got their name for the rabbit ear-like sensory protuberances that sprout from their heads, known scientifically as rhinopores. The slugs can grow up to a foot long and can weigh up to five pounds. The subsist strictly on a diet of algae and their coloration can vary depending on the hue of of the food they consume.

Like octopuses, sea hares can release a cloud of ink when they feel threatened and they tend to die shortly after reproducing, usually after only a year or so. The specimen found at the aquarium isn't quite adult size, though its growth may have been stunted in the holding tank where it grew up.

It was during the cleaning of that holding tank that workers at the aquarium made their fortuitous discovery.

"Every three months or so we have to put on our rubber boots and hip waders and clean out the mud that's accumulated in the holding tanks," said Meghan Holst, an aquarist at the Aquarium. "It can be a chore, but it's also an opportunity to collect specimens for our exhibits--animals that are essentially grown on-site from larvae imported with the seawater. Sometimes we find incredible creatures hidden away in the tanks, like the sea hare."

The sea slug could be immediately reached for comment on why it left California, but it will be on display in the aquarium's Coastal Waters Gallery if you want to ask it yourself.

-- Kale Williams

kwilliams@oregonian.com

503-294-4048