Sunday, March 2, 2014

Salty Chinese Slug Year; or 2013, an Opisthobranch Odyssey

My name is Cass.
I am obsessed with mollusks.
You might say I’m Obsellusked.

Mollusca is a fascinating phylum, especially the briny members of this group. From Octopuses and Cuttlefish to the ancient Nautilus, the delicious and otherworldly Abalone, Limpets, Chitons, Snails, and beyond, I find mollusks to be…actually I'm not sure what I find them to be.
I just need them.
And the ones I need the most are the slugs.  
They haunt me. I want to see one, right now. And when I see one, I want to see another and another. My slug lust is unquenchable. I get anxious when I can’t smell the ocean.
Hardly a night goes by that I don’t dream of them.
And barely a day goes by that I don’t look for them.

Might as well do a big year.

Like all serious sea slug big years attempted throughout modern scientific history, my formal search dates followed the Chinese zodiac. The Year of the Snake proved to be a fortuitous one. Hopefully, The Year of the Horse is even more bountiful.
The Quest was mostly confined to the Eastern Pacific (our West Coast just another East Coast) with a trip to Hawaii to brighten up the list bouquet. Other search waters included the Salish Sea, Monterey Bay, and the Sea of Cortez.
A humble and humbling 55 species were seen, the majority of these in my natal fluids of northwest Washington state, whose near shore habitat has been hailed as the “the equatorial lowland cloud forest of marine invertebrate diversity,” whatever that means.  
Eighteen slugs were seen in Kauai, 3 of these never before reported on the island. Range expansion means champagne!  

As was expected from the get-go, blood was shed during The Hunt, like when I got bit on the hand by a moray eel while photographing this Hexabranchus. What a scorcher! (the nudi and the bite, see below). Common name is Spanish Dancer. Youtube it to find out where it gets its name from. That is, if you give a Flying Dutchman about nudibranchs.

It occurs to me that you birders may not have the foggiest idea about sea slugs.
A few words then, to introduce you to these transcendent little monsters.

Now, I’m not going to drone on about opisthobranch anatomy, with their trending towards shelllessness and thus requiring mind-numbing ways to not get got, including ninja cryptology or the production of toxic compounds that poison their would be predators or even re-appropriating the stinging cells found in their cnidarian prey (anemones, hydroids, jellyfish) and storing these nematocysts in their dorsum, somehow un-triggered, so that anything that takes a bite of them gets a mouthful of harpoons.

No, anatomy is boring, especially the subtleties of the radula, the “rasping tongue,” found in most slugs and other mollusks. Infinite variations exist in these “ribbons of teeth,” which slugs use to eat their way through algae and animals, the beauty of which recalls 19th century Victorian diatom microscope slides, Mandelbrot fractals or Tibetan sand paintings.

It would be unwise to dwell on drab topics like reproductive strategies, like say for instance, the gregarious approach of the California Sea Hare, which has been reported to form a “Roman Circle” of 8 hermaphroditic individuals and copulate for over a 24 hour period, producing millions of eggs. These eggs and the egg masses of other slugs possess a beauty that may remind one of tiny spiral galaxies, shimmering rainbow flags of fertility or, in some cases, Top Ramen noodle packets.

Cuthona divae. Laying its eggs amongst one of its preferred prey, the hedgehog hydroid, Hydractinia milleri, which the adult slug resembles…The Circle of Life, without the cute tigers, backstabbing uncle, the voice of Matthew Broderick, and all that other bullshit. Salt Creek County Park, WA.

This isn’t one of those dry, scientific essays boring you with details of evolutionary divergence amongst an order of animals, from the complete absence of shells in nudibranchia to the cephalaspideans who use their reduced and modified shells to plow through mud and sand, to the Sacoglossa, who have the distinction of being the only known animals on Earth to practice kleptoplasty. Don’t worry I’ll explain, assuming you aren’t a Level 8 nerd or higher.

Elysia diomedea. A sacoglossid or “solar-powered sea slug,” this vegan warrior is essentially consuming algae and then farming the chloroplasts from that algae in the miles of surface area in the dorsal folds of its backs. Mind-blowing, truly debilitating knowledge. This species was found in staggering numbers near Cabo Pulmo in the Sea of Cortez.

No, this essay isn’t designed to explain away the beauty and facemelt of these “divas of the deep” with drab and dry descriptions of their natural history. Instead, let us simply behold them in all of their profound mystery, marinate on their style and let the queries they raise fall away like a waste product in the ebbing tide. Join me in giving a nod of the proverbial furry Kangol for their sexual stamina, their audacity to make bold and slow love for over a day despite the terror of the ocean surrounding them. Let us take away a lesson of tenderness and excess from this heroic and throbbing fact.

Shaggy Mouse Nudi, or Aeolidia papillosa, seen in lower right portion of photo, “rolling out the noodles.” Viewer discretion is advised. Children under 18 should be in the company of a responsible adult or a box of tissues or at least have a clean sock handy.

Melibe, oh Melibe. My first true nudi love. Spring of ’04. I remember it like it was yesterday. She smells like jolly rancher watermelon, swims with a violent and graceful head-to-foot contortion maneuver and feeds by throwing her net-of-a-head out into the water column. I’d swim into it and be happily consumed by her in a second, if only I was a micro crustacean. 1000s of these beauties can be found together in kelp or in eel grass beds seasonally. Common names include Hooded or Lion Nudibranch, both acceptable handles. Freshwater Bay, WA.

Dendrodoris denisoni. Perhaps the most shocking of this years “brain slugs” (to borrow a BB&B concept).  Recalling a benevolent psychedelic brain tumor, this beastie was quite cryptic despite its bizarro texture and colors. Salt Pond County Park, Kauai.

The above photo features the eggs of Fiona pinnata. Also in the photo are pelagic gooseneck barnacles, on which the adults feed. These eggs and prey (and adults in photo below; note my thumb nubbin for size comparison) are on a 12 oz plastic water bottle found washed up in a tide pool in eastern Kauai. These aeolids belong to a family onto themselves and live a mostly pelagic life, floating, feasting and fornicating across the world’s high seas. 

This was a species of nudibranch I’d been dreaming of meeting for years. I was so enamored with them and their bizarre lifestyle that I suggested to my partner of life that we name our daughter after them. My request was politely denied (as were a number my other nudi-inspired names; Dirona, Okenia, Doris, Hermissendra…). I don’t know how many 100s of pieces of beached junk I’ve rolled looking for Fiona. To finally find a few adults (and eggs!) on a plastic water bottle in Kauai was an emotionally devastating experience, one from which I have yet to fully recover from.

Tochni  (Tochuina tetraquetra). A grail species I’ve long longed for…finally seen in August of this year and found somewhat reliably now at this site.  Supposedly, these beasts were/are boiled and eaten by indigenous Aleutians, the Japanese and zee Russians. Never tried them myself, I just want to cuddle with them. This mammoth was about 8 inches long. Commonly known as Orange-peel Nudibranch, a blasphemous and imbecilic moniker for this deity of the underworld. Salt Creek, WA.

Glossodoris sedna. Now this is how you name a nudibranch! After an Inuit Goddess. Not really range accurate but I love the sentiment. This was the last species I saw for 2013, the slug disappearing over the edge of a rock a symbol of the departing year. Note the element of beckoning this individual exudes, an invitation to another year of slug lust. It should also be noted that the gill plume of this species and others of its family, Chromodoridae, vibrates enthusiastically, even in the absence of a strong current. The experts say this is to increase respiratory efficiency but the poets know the truth to be much stranger.

Once a rising star in West Coast Birding Culture, Cass Grattan has since defected and is now in the throes of an all-consuming invertebrate obsession. He is the Munitions Specialist of The Nudibranch Appreciation and Pontification Society (NAPS) and can usually be found in or near a tidepool with a cup of coffee. Those interested in NAPS membership or merchandise (which includes Hooded Nudibranch Hoodies, bumper stickers and slug-themed shower caps) can contact him at

More hardcore nudi photos can be found at Rear Admiral Felis’ smugmug. Previous Cassowary works featured on BB&B include Ode To The Drab Gray Birds Of The Pacific NorthwestZonotrichia, The Four Sparrows Of The Apocalypse;  and his cathartic interview for the Human Birdwatcher Project (Part I and Part II).


  1. genuflect to the depths ill learn to swim for this. thanks Cass.

  2. Buddy, so glad that you found your Fiona pinnata! I remember your then-fruitless attempts at flipping logs, buoys, anything along the water line trying to find those guys. Well done, dude, thanks for sharing this.

  3. I can't say I am a nudi enthusiast myself, being drawn more to the drab and plentiful (think mysids and amphipods) than the solitary and garishly colorful. However, I almost feel a pang of appreciation after reading the good Mr. Grattan's reflections.