Thursday, April 28, 2011

Crabs: “Phuket or Bust”?

Millions of crab megolopae are washing up on shore in Phuket, Thailand! Why? I… I just don’t know.

um, I think you're lost, little megalopae

a closer view of the little guys

The crabs, originally reported as krill, are 2-3 mm long with a carapace width of about 1 mm. They were first noticed in the afternoon last Friday (April 22, 2011). The Phuket Marine Biological Center (PMBC) has been sampling the little guys from Kata and Karon beaches, as the crab babies have yet to be identified to species. The director of PMBC, Wannakiat Thubthimsang, noted that they are definitely swimming crabs, evidenced by the modification of the last pair of their legs to paddles (like blue swimming crabs Portunus pelagicus). Note: they may be just that.

ready: identify!

The scientists are looking into several causes, such as hypoxic water conditions, but some are attributing the presence of millions of crab babies to overfishing: normally fish will munch on these little guys, but with less fish comes less predation and greater planktonic crab survival. Others suggest that it may have just been a fluke: moms releasing their clutches at the wrong place and/or time.

A LOT of lost babies

The world may never know.

Monday, April 25, 2011

Happy Easter!

I hope everyone had a wonderful Easter Sunday! I know for many people, an egg hunt was included in the festivities; there’s an egg hunt going on as I type this here at the UAF Juneau building. What colors did you find?

Just the beginning of my pile o' eggs!

So far, I’ve found some orange and purple eggs (and a white one), which makes me think of crab eggs!

the many colors of snow crab eggs/embryos

Moriyasu and Lanteigne (1998) color-coded the stages of development in snow crab embryos, so that when you catch females, you can determine how far along they are in their clutch maturation:

Moriyasu and Lanteigne's color scheme

Biological Field Techniques for Chionoecetes Crabs (Jadamec et al., 1999) and Biological Field Techniques for Lithodid Crabs (Donaldson and Byersdorfer, 2005) also describe the different categories for egg condition, which refers to embryo development. They include pictures of actual clutches that scientists can use to standardize different surveys’ data.

a myriad of egg colors:
the top clutches are Chionoecetes'
while the bottom are different king crabs' clutches

Based on these pictures, my eggs were a mix of uneyed snow crab Chionoecetes opilio embryos (orange) and uneyed king crab Paralithodes camtschaticus or P. platypus embryos (purple). The white egg could possibly be an eyed golden king crab Lithodes aequispinus embryo, or just a snow crab dud egg (unfertilized). Either way, it had two Butterfinger® chocolate eggs in there, so it was worth it!

Crab Egg Reading:
Donaldson, W., and S. Byersdorfer. 2005. Biological field techniques for Lithodid crabs. University of Alaska Sea Grant. AK-SG-05-03, Fairbanks.

Jadamec, L. S., W. E. Donaldson, and P. Cullenberg. 1999. Biological field techniques for Chionoecetes crabs. University of Alaska Sea Grant. AK-SG-99-02, Fairbanks.

Moriyasu, M., and C. Lanteigne. 1998. Embryo development and reproductive cycle in the snow crab, Chionoecetes opilio (Crustacea: Majidae), in the southern Gulf of St. Lawrence, Canada. Canadian Journal of Zoology 76: 2040 – 2048.

Thursday, April 21, 2011

You’ve been crabbed

Are you looking for a fun way to fund raise? I came upon this hilarious idea (I don’t know who came up with it first, but the Boys and Girls Club of Truckee Meadows, Nevada pulled it off well):

Crab your neighbors!

The idea is, you put a bunch of crabs on a neighbor’s lawn, and then offer to remove the crabs for a “fee”, or “donation” if you want to sound nice. In Truckee Meadows, donations ranged from $25 to $1000 to remove the 80 plastic crabs! Whoever has been crabbed then gets the opportunity to nominate a new crabbing victim.

So fun, so creative, and so crabby!

Sorry, the link to the original article is no longer available, so you just have to take my word for it!

Monday, April 18, 2011

Celebrating Boston!

Today is that most special of special days for marathoners: BOSTON!

In honor of the oldest annual marathon (this is the 115th Boston Marathon!), I wanted to take a closer look at a Boston crab (no, not the wrestling position):

Blue Crab  
(Callinectes sapidus)!

a beautiful Callinectes sapidus

What? An albino blue crab?? You know it!

You can fish for these while visiting Massachusetts. (Or you could try your hand at recreational lobstering, but all I have to say is good luck with that one!) These crabs are true athletes, although they are better known for their swimming abilities than marathon running. See their little paddles on their modified fourth walking legs? Their scientific name even refers to this, meaning "savory beautiful swimmer".

Here's a blue crab eating a clam (I wanted to post a video of one running/swimming, just to keep with the spirit of the day, but the original video was removed from youtube):

Yikes, I hope she waits before running after that meal!

Wednesday, April 13, 2011

What's on YOUR head?

During the Women of Science and Technology presentation, my advisor Sherry Tamone let me wear her awesome hat. I didn’t have any pictures until now:

Showing the girl scouts how calipers work
(I didn’t want to show the girls’ faces b/c I don’t have their contact info to get the OK from their moms,
BUT I did want to show how the one little girl was looking at my hat:
she was either trying to figure out what was on my noggin or plottin' on me!)

Thus began the hunt for more crabby caps!

The cheapest, most similar one I could find:

find it here

A creative crocheted number:

find this beanie at the Moose Threads etsy shop

Or if you’re not ready to don one yourself:

What do you think they're talking about? Probably how awesome they both look.
(find the print here)

Thursday, April 7, 2011

15th AFS Juneau Student Symposium

The Juneau student sub-unit of the Alaska Chapter of the American Fisheries Society (I'm laughing at this sentence! Yikes!) put on their 15th Annual Symposium! It had a wide range of talks, so you better believe there were some crab tidbits!

I won best talk last year (yes, that's me, tooting my own horn. Honk-honk!) and since I'm still in the process of processing (ha!) my hemolymph samples for methyl farnesoate I decided to sit this one out.

Yup, my talk was Fight Club-themed.

This year's crab highlights:

Blue king crab (BKC) Paralithodes platypus were heavily represented today with a talk on their genetics by Jennifer Stoutamore (are BKC from St Matthew and the Pribilof Islands genetically distinct populations??) and a talk on their socioecological impact to the people from the Pribs by Courtney Lyons (how does management of BKC bycatch in other fisheries affect the livelihoods of local fishermen??). Both projects are in the beginning stages, but it was exciting to learn more about BKC in general and see what's being researched.

blue kings from St Paul

Chionoecetes were well covered as well: those two heavy-hitters were Joel Webb looking at snow crab C. opilio fecundity and egg production with respect to stock demography and temperature (females shift from an annual to a biennial cycle of embryo incubation in waters < 0° C! Literally cool, I know!) and Jonathan Richar discussing C. bairdi recruitment in the eastern Bering Sea with respect to predator and parental abundances, and then some environmental variables to boot. And Alexis Hall gave a talk about the relationships between trawlers, crabs, and groundfish, where she'll be looking at whether or not groundfish are profiting from discarded crab bycatch from trawling fisheries; I'm pretty sure this includes Chionoecetes crabs, but she's including lots of crabs prevalent in the eastern Bering Sea, just to, you know, be thorough.

Finally, there were the otter talks. What? What do otters have to do with crabs?

Oh, oh, I see. Zac Hoyt is looking at the recoloniztion of sea otters in southern Southeast Alaska after they'd been overharvested in the 1800's fur trade, asking how this new population is affecting both macroinvertebrates (crabs, urchins, clams, etc) and the fishermen who target them after becoming used to a sea otter-free Southeast. Sean Larson is also looking at new sea otter predation with Zac, focusing on sea cucumbers, which are one of my favorite inverts!

Woo-hoo! As it turns out, the Crab Lab cleaned up at this student symposium: Joel Webb and Sean Larson tied for first place and Courtney Lyons won third place for their presentations! Congratulations!

Monday, April 4, 2011

Challenger Reports

The voyage of the HMS Challenger from 1873 to 1876 was the first of its kind: a scientific expedition to understand the ocean environment and the deep-sea.

the HMS Challenger crew

Among other things, a legacy of this expedition is the amazing drawings of sea creatures that are available for any and all to see! Click here for an index to all the discoveries (scroll down until you get to "Links To The Zoological Reports").

Here are some of my favorites, but you should peruse the plates of all the different reports; they found some amazing animals!

They really inspire me to work on my drawing skills!