Many of you know I LOVE October. I continually sing, "It's the most wonderful tiiiiime of the yeeeeear!" and I'm not talkin' about Christmas, y'all! Among all the reasons I love October (fall colors, Halloween, crab season openers), I just learned it's also National Seafood Month! Yes, not only should you be celebrating everything pumpkin, but also everything locally harvested from Alaskan waters! And to learn more about local seafood, you can read this Seafood 101 pamphlet. The link will bring you to the layout and you can zoom in to read the different articles. Who knows, it may even inspire your next Halloween costume:
Hey there! I've been working on this for a little bit the last 6 years (grad school + coming to terms with publishing my Master's thesis while starting a 'real' job...) but it's finally almost here:
Relationship of molting, gonadosomatic index, and methyl farnesoate
in male snow crab (Chionoecetes opilio) from the eastern Bering Sea
It's been accepted for publication in the Journal of Crustacean Biology and you can read the abstract from the advanced article here. To say I'm pretty pumped would be an understatement! I've had cod and pollock and humpback whales swimming through my brain so much lately that it's nice to get crabby once more! Not like this:
My friend was out on a crab survey this summer and spotted this guy:
Nothing out of the ordinary, right? EXCEPT FOR THESE:
We've seen extra appendages before (here and here). They most often are a result of some trauma to that leg that the crab's physiology tries to heal through regeneration (remember, crabs can rebuild entire legs!) that goes awry. When my friend posted these photos, someone asked if they were mobile or able to move independently. While I wasn't there, allow me to speculate: these bonus crab bits are just that. Bonus. The crab can't control their movement (you can see that they don't have actual joints, just the impression) and if the leg gets dropped for whatever reason and is regenerated, it likely won't have those mutations the second time around. BUT it would be cool if they could move, because imagine how much more scary that would make this guy:
Remember when we learned that crustaceans actually feel pain here? In short, scientists offered crabs two shelters: one normal and one that delivered a shock. After being exposed to the electric shelter, the crabs had a learned response to avoid that sensation (presumably pain) and only choose the normal shelter.
Well, stemming from that research, scientists are now learning that crustaceans may feel anxiety too! I mean, it's not too shocking (I know...) that electrocuting an animal would stress it out, in our human understanding of the phrase, but scientists are observing behaviors that can be attributed to a stressed response. To test for anxiety in crustaceans, scientists exposed some crayfish to an electric field then put them in the test environment. The environment itself had no secret shocks, but rather had different light treatments: light places and dark places. All animals that weren't shocked before placement wandered around in both the light and dark environments, as if they hadn't a care in the world! All animals who were electrocuted prior to placement chose to stay in
the dark places - in the wild this would be like them finding cover and
hiding. They had experienced something that stressed them, so they were staying away from a threatening, exposed place!
"man, you cray!" - 'stressed' crayfish
This, along with some physiological work the researchers did as well, means that instead of calling them "stressed", I can take away the air quotes that indicate I'm just anthropomorphizing their behavior and call them stressed!
A lot of times when I see advances in robotic technology I usually go into a panic about the impending robot apocalypse that's sure to follow. HAVE WE LEARNED NOTHING!?!?!?!
"I want to dance on your bones!" - every robot, I assume
BUT, when I saw the Crabster CR200, my heart instantly melted!
The Crabster is a creation from the Korean Institute of Ocean Science and Technology designed to, you guessed it, walk on the ocean floor! This little fellow can go where propeller-driven ROVs can't and doesn't kick up as much debris, so the video footage captured by its ELEVEN cameras can be clearer with our little crab-like friend. This link had two videos of the Crabster in action, so check it out!
It's like the large, potentially harmful, but still adorable version of these guys I bought my California nieces, so if Aunt Molly approves, so
I mentioned last year that I was going to keep track of the keyword searches that bring people to Snow Crab Love, because some of them were frankly strange. Here are the top 5 non-crab-related searches that brought people here and, I'm guessing, left them asking, "What am I doing here!?!?" 1. Tina Turner
5. Dead Iguana Pictures I seriously have no idea (a) why anyone would search that and (b) why that search word would bring people to my blog MULTIPLE times! Other fun searches were "Captain Picard", "Baby Beagle Costumes", "If I only had a brain", and "Kelsey Grammar" (what?).
Is anyone else singing Sheryl Crow right now? Just me?
It's Science Fair time up here in Juneau!!! That means data has been collected, numbers have been crunched, and posters are being put together for the big presentation this weekend! This will be my third year judging and I'm so excited to see all the projects the high school students have come up with this year!
Last year I was also a mentor (mentioned here) but sadly my student didn't end up presenting her results. It was sad in two ways: (1) she was pretty pumped about the project, but had double-booked the weekend because she was also super involved in a lot of school activities (go get 'em!), so it was too bad she didn't get to present her work. (2) This experiment involved live animals, so had I known she wouldn't complete the program, I wouldn't have mentored this type of project. I take working with animals very seriously and take it to heart if/when any of the animals in my care die.
That being said, I still want to present the fun little project I had the opportunity to participate in since it hasn't been shared yet! Hermit crabs depend on gastropod shells to protect their soft, delicate abdomens. Because of this need for protection, shell strength is an important variable for them when choosing which shell to inhabit. Given the choice in normal situations, it's been observed that hermit crabs will choose intact shells over damaged ones, since the damaged ones would be easier to break into by their predators. We wondered how their shell choice might differ in differing situations: will they make the same choice under stress? How about if they think there are a bunch of potential shells around - will they be as choosy initially? Will they still worry about shell strength???
To test this question, we took hairy hermit crabs, Pagarus hirsutiusculus, that were being housed at the University of Alaska Southeast wet lab and offered them two shells: one intact, one with a tiny hole. When giving the crabs an opportunity to make this choice, we took advantage of their use of chemical cues and exposed them to different "smelling" water. We exposed some of the hermit crabs to water that smelled like a known predator, the Dungeness crab, to act as the stress treatment. We exposed others to water that smelled like dead snails to mimic a gastropod predation event, or a time when several snails are being eaten and therefore leaving their shells up for grabs. We finally had a control treatment where the hermit crabs made their choice in the same water that had been pumping through their holding tanks.
In order to encourage shell selection, we had to gently remove the hermits from their original shells (crazy easy to do without any harm to the crabs!). We saved their original shell so that they could move back into it when the trial was finished. We also measured their original shell's weight so that we could offer them test shells of similar size/weight (we didn't want to give a big crab a small shell!).
science! collecting naked crab weights!
We measured the time it took for them to approach a shell, the time it took for them to enter a shell, and their shell selection. We took note if they changed which shell they chose too, just in case any of them had buyer's remorse.
choices choices: the two shells offered are from the same species of snail,
but one is damaged goods and one seems shiny and new
(the small white thing in the leftmost part of the tank is a bit of gravel)
What did we find? For all treatments, the hermit crabs chose the intact shells over the damaged shells. This wasn't too shocking, but it was still interesting to see that, even under stress (Dungeness-scent) or at leisure (dead snail-scent), they still made the same basic decision.
more hermit crabs chose intact shells than damaged shells
and rarely changed their minds, although one crab switched from
an intact shell to damaged one in the predator treatment...
The time it took for the crabs to approach a shell and enter it were very similar. It seemed like some of the crabs would just wander around the tank for the most part and sense the shells by touch rather than sight. Once they touched a shell, they would hurry their little tushes into it! The time it took for them to find the shells was roughly the same across all treatments (ie "there was no significant difference in average time for first approach or shell entry across treatments (ANOVA, p > 0.05)").
I was also inspired by my renewed interest in rhizocephalans after seeing UAF student Leah Sloan's zombie-themed poster at the Alaska Marine Science Symposium. So I came up with this beauty that you can share with your loved ones or your not-so-much-in-love-but-you-don't-hate-them-either ones!
To make this heart-warming card: 1. Download the PDF 2. Print out the card and fold on the dotted line 3. Give to someone!
Are you guys ready for the final crab friend I found in Oregon!?!? Let's do this one more time:
Let's recap quickly: I was down in Oregon for our friends' wedding. The friends we were staying with treated us to a lovely walk on the beach and we were happily surprised to see a live smooth bay shrimp and a live purple shore crab! That would have been enough, but the next thing we saw knocked my socks off:
Holy mole-y! (Ha!) I can't tell you how excited I was to see this guy! Unlike our two other friends, the mole crabs I found were, sadly, dead. But thrilling nonetheless. Mole crabs live in the surf zone and burrow into the sand backwards using their modified, trowel-like telson. This digging behavior is why they're called "mole crabs".
"Also because we are6.02 x 1023 times cuter than any other crab" - mole crab
I just can't get over their unique body shape! It was such a treat to see these guys and a perfect way to end our trip in Oregon!
Last week 2 weeks ago (time flies!) I attended the 2014 Alaska Marine Science Symposium, and boy was it crab-tastic! I went to present a couple posters on my work with the Gulf of Alaska Project (my portion is studying baby fish body condition), but you better believe I stopped at all the crab posters I could find! Here's a run-down of some of the neat crabby things I learned: Snow crabs are loving detritus up in the arctic! Lauren Divine looked at Chionoecetes opilio stomach contents from crabs collected in the Chukchi and Beaufort Seas. Along with detritus, crabs were eating polychaetes, bivalves, brittle stars (you can see a pile of them from this post), and other crabs including opies!
Lauren showing off her poster and special friend
that's a larger-than-life snow crab ready to show you...
...its stomach contents!
Alaska Department of Fish and Game is mapping Tanner crab (Chionoecetes bairdi) habitat to better understand their distribution off of Kodiak. The fun part of this: underwater pictures of crabs in action!
Ocean acidification will affect larval Tanner crabs as the ocean's pH drops. Here's Chris Long presenting his work where they exposed brooding females to different levels of pH (the lower the pH, the more "acidified" the water is). The greatest effect was toward larval survival. He also gave a talk on how a similar experiment affected the embryos of Tanner crabs (there's a difference... I can explain further if you'd like) and they weren't doing too well either.
over-achiever: giving a poster presentation AND a talk!
Remember how I said aging crabs was near-impossible? Alexei Pinchuk, Ginny Eckert, and Rodger Harvey are out to prove me wrong!
"Development of Biochemical Measures of Age in the Alaskan Red King Crab:
Towards Quantifying Thermal Effect on Aging"
Last but not least, I learned about ZOMBIE CRABS!!! (No, not these zombie crabs.) Leah Sloan, a UAF grad student, is looking at the distribution of that nasty parasite, the rhizocephalan, and how it may be affected by temperature. The infected king crabs she's studying are referred to as 'zombie crabs' because their bodies have basically been hijacked by the parasite to be a walking, eating, parasite-brooding machine! She's answering her temperature question by exposing larval rhizocephalans (aka parasitic barnacles) to different temperatures and tracking their survival. I'll interview her soon for an "Ask a Grad Student" post so we can all learn more.
she had me at "Zombie"!
I took so many other crab notes, so we'll see if I can share them all with you over the next... year!?!? By then I'll be ready for another round of Marine Science Symposium fun!
I last left off with my friends and me discovering a still-very-alive smooth bay shrimp and putting it back in the ocean. As we reached the jetty near Yaquina Bay and admired the sunset, we found another little crustacean first thought to be dead.
"I'm so thirsty!" - purple shore crab
He was a little purple shore crab (Hemigrapsus nudus)! He was very nude, but we tried not to make him feel too self conscious about it. I'm not sure why purple shore crabs are also called 'naked shore crabs' since all crabs are naked save for maybe decorator crabs (when they dress up and look fabulous!), but I think it hails from a comparison with the other common shore crabs nearby, the hairy shore crab (Hemigrapsus fully-dressed-icus oregonensis). You see, the purple shore crab has smooth legs whereas the hairy shore crab has lots of little hair-like setae along its legs and claws.
"That's right! I'm as bald as Patrick Stewart!" - purple shore crab
Like the smooth bay shrimp we found, this purple shore crab also gave us some signs of life so we quickly found a sheltered spot for him in the water by the rocks.
We have one last stop in our Oregon adventure, so don't go too far!
I mentioned in the last post that I was headed to Oregon for a wedding. It was beautiful and touching and just plain fun! The next day we took advantage of our proximity to the coast and headed out for a walk near the Yaquina Bay State Recreation Site. I wasn't expecting to see much other than waves, sand, and sun, but my friend Alice spotted this little fellow:
a sandy-colored smooth bay shrimp
We thought it was dead since it was just lying in the wash zone of the beach. Either my husband or Alice went to pick it up (I don't remember who) and it flipped away from us! We all gave a jump and a scream, then picked it up and put it back in the ocean! It was a good start to a fun beach walk!
This little shrimp isn't just your average cocktail ingredient. Oh no, he's got quite the story. Smooth bay shrimp (Lissograngon stylirostris) host a nasty little parasite named Argeia pugettensis, a bopyrid isopod. The isopod will attach itself to a shrimp's gills and use the shrimp's carapace as an extra layer of shelter. The first one to attach to the shrimp develops into a female.
Any subsequent parasite to enter that shrimp's gills will become male and fertilize the female parasite's eggs. Once the little larvae hatch, they head out in search of an intermediate host (namely a calanoid copepod) to ruin someone else's day develop further until it can start the whole process over again by swimming up into a shrimp's gills.
"Gross Steve, you've got something on your back!" - Larry the shrimp
"AH! Larry, you've got something on YOUR back!" - Steve the shrimp
"AHHH!" - Larry and Steve
"AHHHHHH!" - all the shrimp EVERYWHERE!
Luckily for the shrimp we found, it wasn't infected with anything.
I'm so excited for what 2014 has to bring! The most recent thing will be our dear friends' wedding this weekend, so I feel like we're starting the year off on the right foot! Before we head out to celebrate I wanted to look back on 2013 (like I did last year with 2012). So, without further ado, here are the top 10 posts from last year: 10. Let's talk about crabs, baby! This was a review of a different color: going over the most recent crab chat I had with some Deadliest Catch fans! I answered the question, "Who can fish in Alaskan waters" immediately, but I'm realizing that I still need to write a post about those infamous crab farts! Hooray for 2014!
9. Cod are just like people Cod like to eat snow crabs and my fellow University of Alaska Fairbanks alum Laurinda Marcello tells us how that affects the snow crab population. A lot of you guys already know the answer to that, but for those of you who haven't read the post, click the link to see if snow crabs should be more afraid of cod or themselves! 8. Happy New Year! WOOOO! You guys like to party just as much as this hermit crab!
um, you got a little something on your face.
7. Trading WHAT for protection? Fiddler crabs: just when you think you might start liking them, they go and do something like this. What's the "this"? Living a 'free love' lifestyle in the name of property protection. You do what you gotta do, fiddler crab females, just don't expect me to bring a casserole over for the next "potluck" you throw, OK?
4. Big Ol' Crab! In complete contrast to #5, this post was all about the largest recorded snow crab ever. I had to guestimate the actual size based on weight and crudely photoshop a picture, but you all got the idea. 3. Say "AAAAAAAH!!!"
2. hermit crabs do the twist Come on hermit crab, let's do the twist! (Any Chubby Checker fans out there?) You guys must have been really interested in hermit crab abdomens and whether or not they twist the same way. Either that or you really liked my Beyoncé joke. 1. King crabs are red, King crabs are blue, This post taught you all, How to tell the difference!
"I'm red" - Paralithodes camtschaticus
"I'm blue" - Paralithodes platypus
It also taught you that I'm a terrible poet. Well, that's it! Let's see what 2014 has to offer!