Gon’ Crabbin’

Three weeks in Friday Harbor, and the time has flown by. As you may have already known both Steve and I are working on the organism Oregonia gracilis, a decorator crab. Steve is working with the larval and beginning juvenile stages. These early stages are teeny tiny little guys. About two weeks ago he needed to start collecting some of the larvae and we both just wanted to have some fun, so we decided to start the collection process. Now I don’t know about you, but from growing up just outside of Annapolis, MD when I think about catching crabs what comes to mind is tying some chicken necks to a string, throwing them in the water and waiting for a crab to grab on. Contrary to popular belief this isn’t how you catch larvae.

 

There are a couple different methods you can choose from to catch these larvae, but basically all of them involve seeing these tiny specks swimming around in the water and scooping them up into a plankton tow or small mesh net. However, in order to see and scoop these crabs you first have to find them. This part can be pretty tricky when you’re dealing with something that is only about a millimeter or so long in a great big sea. Luckily Biologists have a trick up their sleeve, Nightlighting.

 

Nightlighting is exactly what it sounds like. Once it gets dark (about 10:30 here) you take a nice big waterproof lamp and dip in just below the surface of the water. In a matter of minutes you’ll have larvae swarming the light, give it another minute or so, you’ll have shrimp, jellyfish, small fish, and every-once-in-awhile 1 ½ ft polychaetes swim by. The larvae are attracted to the light, and a lot of the other organisms are just there for some easy dinner.

With enough luck nightlighting is a very effective method for catching larvae. We have been out about 4 times since we’ve been here, and every time we manage to see something cool and new. Also after some very cold time dipping our hands in the water we took a few nice pictures.

 

Gotta go check on the crabs! Until next time from the West Side.

Plaid, Flannel, or Argyle? Decisions, decisions…

Hey guys, I’m Joe Odierno, here at Friday Harbor Labs with Dr. Jacobs, Deanna, and Steve. This is our 3rd week here in the San Juan Islands and each day is filled with new and different surprises. From getting to go out dredging, to starting experiments we have all been anticipating for months, to seeing all the awesome organisms this place has to offer, it’s really a sight to see.

 

Between the whale watching, seal sightings, and adventure hikes, we all work hard and long on our research in the labs and field. I’m here studying Oregonia gracilis, The Graceful Decorator. These crabs are apart of the Spider Crab family and will take anything they can get their claws on and use it to decorate they carapace and legs. They mostly utilize varieties of algae, bryozoans, and sponges. It has been seen that other crabs in their order will prefer to decorate with one material more than another. I’m looking at the question, do these crabs prefer one material to another, or do they just take whatever is within claw length? I want to see if these guys go to their favorite department store and pick out their favorite shirt, or if they just go for the first one they see.

 

So the general process of my experiment is go out to the docks, swoop 30 to 40 of these guys into my net, bring them back to the lab, strip them down (un-decorate them)-which I must say is a pretty arduous process that usually goes long into the night- using my arsenal of watchmaker’s forceps, paintbrushes, forceps, and a handy dandy dissecting microscope, give them sometime to recover, and the next day unleash a fury of red algae, sponges, and bugula on them.  After about three days of decorating I re-strip the crabs, dry the used materials, and weigh them. I actually began my first real round the beginning of this week, so I’m stuck in this excited, edge-of-my-seat, come on guys decorate decorate decorate, type of state. Which I must say isn’t a bad thing.

 

Well we gotta go catch a boat, so that’s all for now from the West Side.  Until next time.

 

Joe Odierno