Lady crabs roam all over the east coast from Georgia up to Canada! I saw them a lot when I was beachcombing on Long Island.
peek-a-... oh wait.
Another name for the lady crab is the calico crab (or the sand crab... so bland). Careful when you think of 'calico crabs' though, because O. ocellatus is not to be confused with another calico crab Hepatus epheliticus. The lady-crab-version of calicos are swimming crabs, like the blue crabs and devil crabs we've seen. (Unlike blue crabs, they're not really considered tasty, so humans leave 'em alone. Other animals eat them though, including lobsters!)
Telling the two calicos apart is pretty easy. For one, the swimmerettes are kind of a give-away (H. epheliticus doesn't have them). But if that doesn't do it, just think: the lady/calico crab O. ocellatus has little dappled spots like an ocelot! Eh? EH?
you see it?
OK. So this crab may be a lady (though, obviously, there are male Lady Crabs... I think they prefer the name 'sand' in that case), but she's a fighter: these crabs are known to be aggressive, and are not afraid to use their sharp chelae in order to defend themselves.
This crazy furry picture made me think of another fuzzy-sleeved crustacean:
The Yeti Crab!
I'm in love!
You've probably seen this guy at least once in the "Whoa, that's weird" section of the news (my first stop for news readin'). These amazing 'yeti' crabs were found 1.5 miles beneath the surface of the ocean at hydrothermal vents about 900 miles south of Easter Island (you know, the one with all the heads). That's where those beautiful hairlike filaments come into play: they use the filaments (with sulfo-oxidizing bacteria) to filter toxic minerals spewing forth from the vents.
"Oh hi! I didn't see you there, what with my teeny tiny eyes."
What do they eat in this crazy environment? Mussels of course! The yeti crab is believed to be an omnivore, and was seen munching on mussels crushed by the deep-sea subs.
I think it's time I come clean: the yeti crab is actually a squat lobster! But, in my defense, squat lobsters are more closely related to crabs than true lobsters. And, come on, aren't you glad you learned about the yeti crab today? I know I am!
this is a male Kiwa hirsuta: see how he almost has
a lobster tail, but it's SQUAT? If you took a peek under that tail,
MacPherson, E., W. Jones, and M. Segonzac. 2005. A new squat lobster family of Galatheoidea (Crustacea, Decapoda, Anomura) from the hydrothermal vents of the Pacific-Antarctic Ridge. Zoosystema 27: 709-723.
Or, excuse me, the artist formerly known as Prince. My bad.
"I love everything purple.
Purple Land Crab!"
I was inspired by the purple blue crab Callinectes sapidus (from this post) to track down a fo' real purple crab. Look at the beauty that I found for this week's Crabday:
Sesarma impressum impressing me! Hey-oh!
Can you believe those claws? I love the polka dots. They're actually little bumps called 'tubercles', which are also on the underside of these cool crabs. The tubercles on their ventral side (I could say 'belly', but that wouldn't be quite right... you get the idea, I hope) are lined up in such a way that they actually make channels through which water can flow!
Yeah, water flows from their branchial chamber, through these channels formed by tubercles picking up oxygen along the way (since it's on the outside of the crab), then heads back into the branchial chamber at the base of their legs! It's a built-in (out?) re-oxygenation system so they can reuse water for their gills!! The whole thing is called 'the reticulated pterygostomial region' and is specific to sesarmid crabs. (Break out that fact with your friends tonight. Everyone will want to talk to you.)
Purple land crab: "Reduce, reuse, recycle!"
Needless to say, these crabs are pretty cool. Most photos I found were from Taveuni, Fiji, although they roam all over, from Kenya, Madagascar, and the Red Sea, to Tanzania and the West Indian and West Pacific Oceans. Little is known about their behavior (at least with what's readily available for me to find), so these beautiful little land crabs could be burrowers OR they could be tree climbers! Or both? Who knows??
a sweet little purple land crab mama
(you can see her full clutch kinda puffing out from her abdominal flap)
What is known is that these crabs are pretty and pretty awesome!
Researchers wanted to learn the factors affecting mate selection in fiddler crabs, specifically the Australian Uca mjoebergi fiddlers (thanks, Laurinda, for sending me this article!). You see, female fiddler crabs are VERY picky when it comes to choosing a male. Also, it's just plain fun to watch fiddler crab behavior!
So the researchers mimicked the crabs in two ways:
1. make a robocrab arm to wave to the ladies at different sizes and speeds
2. lie to the ladies, as male fiddler crabs are apt to do, by making them think they are legitimate mates and not just some flailing piece of machinery (read another example of fiddler crab dishonesty here).
Are you a man or a machine?
Actually, you look like a pretty cute male U. mjoebergi!
It's actually pretty cool. Not surprisingly, females preferred "males" with larger claws, but they also liked faster waving speeds. Researchers were then able to learn that males purposefully situate themselves around smaller, slower neighbors in order to make themselves look better! They even go so far as to protect their weaker neighbors, but with an ulterior motive, not "Oh, I'm just a nice guy".
what, you think Ryan Gosling is the only one to say "Hey girl"?
Another study showed males "eavesdropping" on their neighbors to learn where the ladies are! Fiddler crabs. Pfft.
Remember when I was confused here about no crabs in Antarctica, then discovered here that they were, in fact, moving in on that icey continental shelf? Well add this next crab to the list of crusty invaders:
My friends Jon and Kasey sent me a new article out about this Crabday's king crab species making its way towards Antarctica (where it had previously only been found in the Ross Sea). This time the large king crabs were found in the Palmer Deep, a basin 120 km onto the arctic shelf. N. yaldwyni is even reproducing: scientists are estimating 1.5 million king crabs within the basin of Palmer Deep!
a lovely lady with her healthy clutch
Just as reported with earlier king and stone crab finds, these crabs are moving in toward Antarctica with the warming water temperatures. N. yaldwyni can't tolerate temperatures lower than 1.4 degrees C, which is currently holding the crabs at 850 m depth (it's warmer the deeper you get. Go figure.)
gotta love the striking red of these beautiful lithodids!
Wherever these new crabs have roamed (as their crab tracks are visible!), there's been reduced biodiversity for the benthic invertebrates. Animals, like the resident echinoderms, are unused to the crushing claws of these new predators and have no chance! But they're not necessarily the top predators, with another newly discovered king crab species being found in the belly of an Antarctic toothfish!
two N. yaldwyni walking all over like they own the place
Read the paper:
Smith, C. R., L. J. Grange, D. L. Honig, L. Naudts, B. Huber, L. Guidi, and E. Domack. 2011. A large population of king crabs in Palmer Deep on the west Antarctic Peninsula shelf and potential invasive impacts. Proceedings of the Royal Society B (published online): doi:10.1098/rspb.2011.1496
Bruce is a 10-kilogram Tasmanian giant crab, Pseudocarcinus gigas. He got that big feasting on crabs, snails, and other inverts in the waters off of Australia (the P. gigas range is from the Perth coast in Western Australia to the coast of Victoria, at depths of 100 - 270 meters!).
"I'd shake your hand, but I like to use my massive claw
for crushing food items and the like. No offense."
Bruce is the big man on campus at the Sydney Aquarium's Claws exhibition while the international star, a Japanese spider crab (Macrocheira kaempferi - like this guy), sits out her quarantine: the aquarium needs to be sure, assuming the crab is female, no larvae will make their way into Australian waters, which should be set up anyway for all the crustaceans they're housing (we have a system at the University of Alaska Southeast wet lab to make sure no snow crab larvae make it into southeast waters).
"I'm kind of a big deal. Like, 4-meter leg span big."
Plus they're testing Crabzilla for any possible radioactive contamination from the Fukujima plant leak back in March, as the large spider crab caught for this exhibit was brought in after the Japanese tsunami. Which is a good thing to test for, because you don't want this to happen: