Thursday, February 16, 2012

Visiting Arabia: Slugwatching 201

Searching for slugs among seagrass.  Does science make my butt look big?
My name is Noah DesRosiers, and I am a slugaholic.  No, I don't consume them.  To do so would be to invite severe physical discomfort, as many of the marine forms I crave are toxic and all are slimy.  (Not sure how a diet of sea slugs would affect my mental wellbeing; I did lick a live Thysanozoon flatworm on this trip, which was minding its own business atop a coral head, but oh they are so cute, that one can't help but get ideas sometimes - for example, to taste them.  Point being, I think I was sufficiently mentally ill beforehand; no need to worry about increased effects.)  Rather, I am addicted to finding these little creatures, understanding them, and telling stories about them to those who listen intently/politely, depending on the situation.  I finally admit it, folks - I have been a naturalist out of control, forsaking friends and food for further Phyllidia finds.  This past trip to Saudi Arabia helped me realize this.  So, "Slugwatching 201" is a reflection on my gritty slugaholic past - how it started, why it's so fulfilling, what I was doing wrong - and the insights that are helping me evolve from recovering slugaholic to avid slugwatcher.  The post is peppered throughout with slug biology, conservation concerns, and photographic/hand-drawn illustrations.  Enjoy!

KAUST beach at sunset.
"Sea slug," at the term's most complete interpretation, refers to animals of the Phylum Mollusca, Class Gastropoda, Subclass Opisthobranchia.  About 6,000 species have been described; from the rabbit-like, red ink-squirting sea hares (Order Anaspidea) to the flamboyantly colored Nudibranchia.  I always knew they totally rocked (like most marine life), but my obsession only developed in early 2011, as a stress-reducing hobby.  At that time, I was locked up at home typing my Master's thesis.  Graduate students around the world cringe at the memory of their thesis-writing anxiety; keeping strange hours, sleeping stranger hours, and only allowing yourself the occasional meal.  After a particularly fervent multi-day typing session, during which I lost all track of time, place, and undergarment freshness, I hobbled out of my apartment like a mummy from a crypt, seeking physical and moral nourishment.  Could I do this science thing for my whole life, I asked myself?  Could I endlessly analyze and coldly quantify the sea's mysteries?  Normally, I'd fight this feeling with a party, but I was too worried about the dangers of a hangover to my writing ability, which I'd need to use again all too soon.  So instead, I grabbed a bottle of water and a banana, strapped my snorkel fins to the back of my motorcycle and accelerated towards the sea, that vast blue source of all my inspiration and love.  Whipping winds on my face and sunlight on my outstretched arms thawed the tension in my mind as I zoomed towards the campus beach.  When I arrived, I groggily dismounted and began to approach the water the way a person dying of thirst approaches an oasis, donning snorkeling gear as I went.  (Er, read another way, that suggests that all people dying of thirst typically don snorkeling gear as they approach an oasis, which is probably still something I would do.)  At the water's edge I collapsed to my knees and splashed over forward into the undersea world.  Though it was only a muddy algae field three feet deep, it felt like that first hug you get from a lover you've not seen in months.  I hovered there for three hours.  Knowing I would have to return to work soon, I was determined to maximize that experience.  Seaweeds that had once passed underfoot unnoticed now received my full attention.  While turning over algal fronds and broken seashells, my vision adapted to a one-centimeter world... and I began to notice them.  The little mystery creatures.  Few I'd ever seen before.  Many of which were slugs; purple, blue, yellow, rainbow.  That day, it was as if they wanted to be found.  My eyes went wide and my stress drained out of me like urine through a rental wetsuit.  I was hooked.

Little creature photography studio; Chromodoris charlottae pictured.
This new activity became my thesis survival tool; a short, refreshing, and intimately solo endeavor, away from the prying questions of... er, an advisor.  A couple times a week, I'd visit a new stretch of campus shoreline and bring back any tiny mystery creatures to my apartment.  I'd put on the blues rock music, crack open a beer, light the hookah, bust out a camera, and shoot away into the night until that perfect psychedelic slug shot materialized amid the smoky haze of my mind...

To the concerned parents, allow me to apologize for romanticizing such destructive behavior; one should never remove marine life for one's own personal pleasure.  Fellow divers and nature enthusiasts will emphatically agree; don't touch wildlife!  If you don't know what it is, you might kill yourself, or the organism - and that's no fun for anyone.  Of course, I'm a marine biologist, I had told myself.  I know what these creatures are, and gosh darnit, if it might be a new species, who better to investigate than me?  (Aside from reputable, published sea slug biologists, or opisthobranchologists, as their business cards might say.  But this logic does not work with the infatuated.)  When I finished my thesis and left Saudi Arabia, the bad habit came with me to subsequent seaside dwellings around the world.  In Malta, Costa Rica, and Seattle I told myself that I was allowed to take them home because I lived so close to the sea, and I'd let them go.  Just allow me some detailed photographs, and I'll only pickle the critter if it can't be identified, right?

Hotel ashtray as makeshift studio for  Hypselodoris agassizii, from a tide pool in Montezuma, Costa Rica, 2011.

Thuridilla hopei, Malta, 2011.
Well, wrong.  Despite my most noble intentions, sometimes these creatures died on me.  You see, tiny invertebrates are fragile; especially the little soft-bodied sea slugs.  In the wild, they crawl freely through oxygen-rich waters, their mucous-y membranes exposed to the sea's particular bacterial fauna, over patches of widely dispersed tiny foods on which they need to feed often.  Sometimes I wouldn't be able to release these creatures back into that environment until the next day, yet signs of stress were obvious almost immediately.  Compare the colors of these Thuridilla hopei from Malta (left, upper), captured not an hour before the photograph was taken, with a photograph of the same species in its natural environment (left, lower).  Massive color fade!  When I brought home aeolid slugs, they would sometimes autotomize (selectively amputate) their cerata (tentacles).  One time I even woke to find myself a midwife, as a captured Chromodoris britoi had laid eggs overnight in a bottle (below photos, click to enlarge).  Out of scientific curiosity and guilt I desperately tried to care for these doomed offspring without the appropriate technology.  With various bottles, some tubing, and a lighter I managed to MacGyver a passable slug egg incubator in my bathroom.  Of course I could never hope to feed the near microscopic larvae after the eggs hatched.  And despite my obsessive curiosity, I had not published any scientific observations or new species descriptions.  Thus, removing these found creatures became an increasingly unjustifiable bad habit.

Unidentified (suborder Dendronotina), KSA, 2012.
You might think it's no big deal for me to remove a couple slugs, either because you think one individual doesn't matter or because you think that slugs themselves don't matter.  To address the first possibility, consider that almost all the slugs I've photographed were only seen once despite hundreds of hours searching for them underwater.  In addition, I've noticed that I find different groups of species on otherwise identical coastal reefs only 50 km away from each other.  These observations, plus the fact that most slugs live for only a year, suggest that slugs may be exceptionally rare on the reefs and sensitive to disturbance.  The death of a few might alter the species abundance on a reef for generations.

And if you think slugs themselves don't matter?  Well, a critter has a measurable lifespan with or without humans, but asking if it "matters" changes with human whimsy.  Our assignment of "value" to a species reflects what service we think it provides to human wellbeing - usually as a food source or an important factor in the food production system.  I shyly admit that while we know all life is interconnected and we understand little about the role of slugs in a marine ecosystem, it is possible that their low abundance, occasional toxicity, and minimal prey consumption make them an insignificant variable (or even a dead end) in the food web.  But we do find them to be breathtakingly beautiful, and that does matter to us, even if it doesn't benefit our species' survival.  (Of course, sea slug photos are my way of wooing women - I tip my hat to you, Darwin.)  It matters because those of us hypnotized by such beauty are stimulating the global economy with the purchase of fancy camera equipment and plane tickets to tropical destinations.  Yep, slugs create wealth - as plenty are discovered every year, so too does the potential inspiration grow for artists, photographers, scientists, divers.  Slugs have earned respect, and that means no removal by a hairless monkey dreaming of scientific glory unless the sacrifice is truly justified.  Perhaps when I get a grant.  (As a last point about a slug's worth, I can't resist wondering what a slug would say [if not a ridiculous premise] about a human's purpose?)

Chelidonura livida use sensitive oral bristles to track prey!
These insights are evolving the way I interact with slugs.  I have admitted my wrongdoings to show you this perspective shift.  On my January 2012 visit to Saudi Arabia, I finally had the opportunity to take photographs with a highly specialized underwater camera system.  I had gained the ability to get quality images without disturbing these creatures; note that the later slug pictures in this post are set in the natural environment.  This ability, coupled with the slug biology research I did for my Saudi show and the heady pride I felt after that performance from the compliments of stunned audience members, made me feel like part of something large and legitimate.  I was probably becoming somebody's role model, and I was also beginning to see that I had some truly special talents that deserved to be developed to their fullest potential.  Perhaps I realized that my interaction with slugs and other little creatures, even when in its most formalized scientific expression, was meant for the benefit of society, not just my human career.  Choosing to secretly investigate these creatures in destructive ways, especially since I was one of the only people to ever witness them, was endlessly selfish.  I recovered from the haze of Slugaholism and enrolled in Slugwatching 201.  Now that I had developed a knack for finding and identifying these wonderful creatures, how could I take this raw skill and passion and carve it into an efficient, fulfilling machine for discovering, recording, and sharing them for the benefit of society, science, and my wallet?

Undescr. Dermatobranchus sp., KSA, 2012.
One of the directions I took this train of thought was to figure out what scientific questions I could be answering.  I'd already been in communication with Dr. Bill Rudman, curator at the Australian Museum in Sydney, about many of my sluggy discoveries.  A couple of my finds are potential new sightings for the Red Sea.  So how do I report this appropriately?  I asked several zoologist friends from Germany and the USA about writing species descriptions.  I am learning that modern zoological research must address genetic relatedness to similar species, and that several individuals of the proposed new species must be collected in order to ensure that any unique physical characteristics described are not chance mutations.  I have collected a couple individuals of scientifically undescribed species I'd found on this trip, but I've come to the relaxed conclusion that there is no need for more collection until I learn how to scientifically describe these species.  For now, I can rest easy with in-situ photography and later identification of found creatures.  Now, when I rock out to the world of slugs, I'm processing photos, writing stories, or reading papers instead of making martyrs of innocent rarities.  I have plenty of options ahead of me to develop; I'm excited to jump in and see where they take me.

I invite the rest of you to the hobby of slugwatching.  Here is your Slugwatching 101. You can find these creatures as easily as I have, if you want to!
  • When diving/snorkeling, adjust your view to the world of the tiny creature; remember a hole you can't even fit your finger into can be an apartment complex to a slug.  
  • Get yourself an underwater camera so you can photograph what you find; most of these creatures are so fragile they will fragment upon contact, so don't repeat my mistakes by collecting them!  
  • Identify your photos later using wonderful resources on the internet (, or dozens of immensely useful wildlife identification guides (e.g. Nathalie Yonow's Sea Slugs of the Red Sea, 2008, 304 p.).  
Sure, it will be slow at first because you won't know an Aeolid from an Anaspidean.  But you can start by Googling "<your slug's color>," "Red Sea," and "" before resorting to just random species name clicking (there are ~3,000 listed on the forum). With every positive ID, you're building a nature framework to refer back to that will make all future inquiries easier.  Good luck, and maybe someday we'll be at a trendy New York City hotel snobbily discussing the day's finds from the mundane algal muck of Manhattan's Upper Bay.

Opisthobranchs from the January 2012 Saudi Arabian Red Sea excursion
One of this trip's new discoveries - Oxynoe sp. 4, previously only known from Micronesia!

Thorunna africana
Flabellina bilas - with socks on cerata?!

Bulla ampulla - with isopod sidekick in the water above its eyes!

Glossodoris pallida mating on the bottom of an overturned rock.

A tiny unidentified Phyllidiid nudibranch (wart slug) cruises the algal turf.

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