Thursday, October 23, 2008

Wharf roaches

July on the jetty

The young man had the requisite tattoos and low hanging day-glo surfer trunks. His girlfriend looked bemused as he lifted a chunk of granite over his head.
"Got it!"
I figured he'd pegged a rat, he was so dang proud of himself.
Guess it doesn't take much to impress his girlfriend.

He had slaughtered a sea slater, an aquatic roly-poly. Sea slaters, alas, are also known as wharf roaches, a fatal misnomer for this particular critter now splattered on the jetty.

I'll give the guy's girlfriend this much credit--she wasn't half as impressed as he was.
***

When I think crustacean I think food: crabs and shrimp and lobster and crawfish! All crustaceans, all delicious.

While most of us think crustaceans live in the sea (and they are indeed the most numerous animals there), a few species have managed to poke their way out onto land. The roly-poly (pill bug, potato bug, woodlouse--all the same cute critter) is a crustacean in the isopod order. It needs moisture to breathe through their gills, which is why they tend to hang out in damp places.

The "wharf roach" is also an isopod, a cousin of the roly-poly. They can be found scampering around the jetties in Cape May, and except for the occasional H. sapiens impressing his girlfriend, their biggest concern is crabs munching on them.
***

The books will tell you that sea slaters are nocturnal. I will tell you that they are quite busy during the day as well, but are quick to scurry into crevices if they see you approaching.

If you sit still on the jetty for a few minutes, they will come out. A few may even wander over to your bare foot. I've never been bitten by one, can't imagine that they could bit if they wanted to.

They can be tough to see--they can change their coloration to match their background, and the experts will tell you they get paler at night. I have no idea. At night I am too busy trying not to fall off the jetty to concern myself with sea slaters.
***

One reason science has become so alien to most of us is that science is more about advancing careers than it is about advancing knowledge. If a species has no commercial value, little is known about it.

If you want to advance your science career, find an organism few folks write home about, kill it, and peek into its DNA.

I bet Lars Podsadlowski is a decent bloke. He writes papers about the DNA found in mitochondria of various critters. Here's an example of one of his articles:
The complete mitochondrial genome of the common sea slater, Ligia oceanica(Crustacea, Isopoda) bears a novel gene order and unusual control region features (2006)
He's also written about the mitochondrial DNA of mantis shrimp, sea spiders, and bristletails. My guess is he has access to a fancy genome sequencer somewhere in Berlin, and he's made a career out of it.

I am also guessing he's not spent a whole lot of time watching sea slaters wander around the tidal zone.

Or maybe he has. And maybe he's tried to publish articles about the meanderings of sea slaters. If he googles himself, maybe he'll see this and let me know. But I bet I've spent more time watching live sea slaters than he has.

Seems to me we ought to spend more time studying live sea slaters before we chop them up to study their DNA.
***


I am not likely to ever get a scientific paper published, and even less likely to get one published on the activities of a live sea slater. But here's something they can do that's pretty neat.

If you have the time (and too few of us do these days), go find a puddle on a jetty in Cape May. Set yourself down, dusk is a good time--the sun settles nicely over the Delaware Bay. You might even bring your favorite beverage.

After a few minutes, the slaters will accept you as part of the scenery, and go about their business.

Occasionally one will hit the edge of the puddle, and usually it will decide to walk around it.

Wait until a few are near the puddle's edge. Then scare them. (Doesn't take much, you don't even have to say "boo!" Just wave your arms over them. Or just put on your best crab face.)

Most will run away over the dry jetty. A few will run through the puddle, as though it's not there. I think they're actually running underwater, but I am still not sure. Maybe they're running on the surface.

Give me a few more sunsets, a few more ales, and I'll know enough to write my scientific paper.
***

If you've read this far, you have more than enough time to go find your own sea slaters. But one more sea slater story.

Sea slaters are sociable. (OK, to be more scientific, sea slaters exhibit behavior that shows some sort of communication between them.)

When one sea slater is near another, it will make an effort to touch it. They briefly meet, wiggle antennae, then part. I don't speak slaterese, so I've no idea what just happened.

But I know it happened.
***

OK, some folks actually do spend time with live sea slaters. Here's a video of work by Mersiha Niksic, who studies sea slaters while their still breathing. This is a fun video--she's busy chasing "bugs" while seals bark in the background. At least I think they're seals.

Anyone who can ignore seals for isopods is truly dedicated to her work.



1 comment:

Pan said...

Seeing them all over the rocks at my work at Sunset marina in West Vancouver BC, Canada.