Okenia angelensis

Image courtesy of Merry Passage and Phil Garner
Photo by Phil Garner
Divesite: King Harbor, Redondo Beach, California

Egg Mass of Okenia angelensis
Image courtesy of Merry Passage and Phil Garner

Okenia angelensis Lance, 1966

For years now I thought this species was named after Los Angeles, California. Well apparently, I was wrong - old time Brancher, Jim Lance, from Scripps Institute, named it after Bahia de los Angeles in Mexico, one of Jim's favorite Branching spots. The "ensis" ending tells us it was named after a place, in this case the type locality.

Not particularly common at all, a bunch of us were surprised to see a population explosion of this species in southern California recently. Merry captured these photos while diving under Phil and her boat over a muck bottom.

Typically, Okenia, the dorsum bears a series of short, cylindrical processes, 6-9 along the sides and 2 anterior to the rhinophores, and 4-5 down the center of the dorsum between the rhinophores and gill. The body is whitish with brown patches and flecks, as is the base of the rhinophores.

The species is quite small, only to 12mm in length explaining why we don't see it more often, and ranges from San Francisco Bay where I first saw it south through Mexico to Chile.

Nice job Phil and Merry.

Dave Behrens
Sammamish, WA 98074
Sept., 2021
Send Dave email at davidwbehrens@gmail.com

"...Diving under our boat usually involves silty, low visibility water and occasionally something we haven't seen before. I found a single Anteaeolidiella chromosoma, a nudibranch I had never seen. Merry found a Stiliger fuscovittatus, brown streaked sapsucker. We've also enjoyed a few unusual sightings, including mating Navanax inermis, fields of Gould's Bubble snails mating and laying eggs, and lots of tunicates we don't see elsewhere. Because of the low visibility, we only make dock dives when we have mechanical issues with the boat or need to look for leaks in our drysuits. Merry made such a dive yesterday After nearly an hour and a half under the boat, Merry surfaced beaming. This is not unusual. Merry often finds reasons to smile widely after a dive. She found a nudibranch that she has seen twice before but I have never seen, Okenia angelensis. This time, it was an even better sighting. She found more than a half dozen mating and laying eggs on a bryozoan. I rushed back home to get my camera and finished off her tank. We returned today to attempt to improve on our photos from yesterday. I didn't get any sharp photos in the silt but I thoroughly enjoyed the dives..."

Phil Gardner
Sept. 2021

Merry Passage worked as a genetics research scientist at Harbor UCLA for three decades. After retiring she has used her degrees from Arizona State University and laboratory experience as an aid to scuba diving. She spends countless hours researching many of the animals we find underwater. Her home office is filled with binders and identification books from algae to whales.

Phil Garner has been scuba diving since 1989. Before that, he enjoyed free diving the many reefs around Palos Verdes. He met Merry Passage during a beach dive at Marineland in 2006 and they have been a team ever since. Phil is the author of Diving The Palos Verdes Peninsula . He and Merry can be found branching as often as possible.

Send Merry email at mbpassage@yahoo.com
Send Phil email at pacificcoast101@yahoo.com

Phil Garner and Merry Passage

From left to right, Terry Gosliner, Angel Valdes, Dave Behrens La Jolla, Calif.

Send Dave email at davidwbehrens@gmail.com
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