It's all in the DNA

Have you ever found yourself with a water sample and thought, "I wonder if there are larval king crabs in here"? 

  
I see some!

(larval kings photo: Celeste Leroux)

Pam Jensen (et al.) did (from the RACE division of the Alaska Fisheries Science Center). So she developed a quantitative PCR assay to detect baby red king crabs (Paralithodes camtschaticus) and shared her work with us at the Alaska Marine Science Symposium. The "how did she do that" stuff is a little over my head, but the "why did she do that" is pretty neat: little is known about where the larval red king crabs are dispersed throughout the Bering Sea, but there are A LOT of water samples. The assay is used to screen for larval red king crabs so they can know which samples had crabs, and then they can figure out where there samples (and baby crabs) were found. Using the assay, they can detect 1/10,000th of a larva!

 

can you imagine 1/10,000th of one of these little guys?

(these are actually blue king crabs, fyi)

Yes, that's right: 1/10,000th! Of a larva! Those things are incredibly tiny!! That's like the ol' needle in a haystack problem, but you're Magneto so you can detect it like it's your job.

 

Molly: "I sense larval red kings over there"

Read more:

Pam's AK Marince Science Symposium abstract: Development of a Quantitative PCR Assay for Detection of Planktonic Red King Crab (Paralithodes camtschaticus) Larvae (click on the Abstract link to download the book of abstracts and find hers on page 63)

You can also see a poster she made on the subject here.