Body-snatching Barnacles and Zombie Crabs

I stole the title to this post because I loved it so much (and I couldn't think of something better). Turns out not all barnacles are conical-shelled crustaceans that began life as free-floating plankton. Some barnacles are the scourge of any crab they encounter.

When the female Sacculina barnacles invades a crab's body, she does so in an amorphous gelatinous form. She then sends roots throughout the crab's body and begins to feed on it while she grows into a tumorous growth. She even carves out a little spot (the barnacle equivalent of a studio apartment) for the male Sacculina so that she might have baby Sacculinas. But the barnacle doesn't stop there.

Photo source: hku.hk
She seizes control of the crab's mind and forces it to do her bidding. The crab ceases to grow and looses the urge to mate. Instead, it unwillingly devotes itself to caring for the barnacle's eggs, using all of its time and resources to do so (disciplining the barnacles youngsters when they get rowdy, reading to them, singing lullabies just before nap time, etc.). The barnacle even alters the physiology of a male crab so that it becomes a female, so that it might better tend to the eggs.

Come on. I know all creatures need to make a living, but some just take it too far. Some parasites manage to be beneficial, and some become tongues. This one just owns its host in every conceivable way and then discards it. My neighbor has a mooching, parasitical son, who I now suspect might be a variant of the Sacculina barnacle.

Thanks for the link, anonymous.

Covered with Barnacles

Neil photographed this meta-crustacean on the beach at Cayucos, CA. It's a purple shore crab (Hemigrapsus nudus), covered with barnacles.

Did you know that barnacles are crustaceans? I didn't, until Neil told me. Turns out there are 1,800 or so species of the sessile suspension feeders. I agree with Neil's assessment that the barnacles didn't pick a very good place to settle. They'll be cast aside when the crab molts. When will barnacles ever learn?

Thanks for the crab, Neil.





















Here's a picture of my own hand holding what might just be a purple shore crab. But since there are a variety of small crabs that inhabit the western shores of North America (from British Columbia to Baja California), I can't be certain. The little crab was cast back into the tidal pool from whence it came.

You May Have My Watch

Karen reminded me of one of my favorite creatures on the planet. The coconut crab. You needn't worry about encountering one of these in the wild unless you live on one of the several islands in the central Pacific Ocean and Indian Ocean that they inhabit.

Also known as the terrestrial hermit crab, they are also called robber crabs and palm thief crabs, evidently because they have a habit of stealing shiny things, much like my toddler son. Unlike my toddler son, these crustaceans have a three foot (1m) leg span, weigh in at about 37 lbs (17kg), and are equipped with claws powerful enough to crack coconuts open (they love eating and drinking the innards). Robber crab, you may have my watch. I didn't like it that much anyway.

I'm not sure what this crab is trying to accomplish on this pillar. Maybe it's a Samson-style tearing down of the temple. If there was one crab who could pull it off, the coconut crab would be the one.

Dee Dee the Giant Lobster

Some of you may have heard the story of Dee Dee, the giant lobster caught off the coast of New Brunswick.

He spent a week at a fish shop in Shediac, where the 100-year-old, 10 kg crustacean garnered a lot of attention--and competitive bids. Even though an Ontario group offered $5K for him to be served at a banquet, a Vancouver resident, Laura-Leah Shaw, offered $1K to save him. The store owner, Denis Breau, accepted the 'lesser' offer. Dee Dee has since been transferred to a conservation group's aquarium, where he'll live out the rest of his days in retirement from the rigors of the sea.

Denis and Dee Dee will soon be reunited when Denis is able to visit the aquarium. I imagine there'll be salty tears and chitinous embraces for all on that special day.

Thanks for the article, Ida.

Photo source: CTV.ca

Fuzzy Hermit Crab

Back in 2006, American and Kiwi researchers photographed for the first time ever the creatures living near methane vents in the cold waters off the New Zealand coast. The deep-sea communities surrounding these methane seeps are rich in diversity. And I have cherry-picked them to bring you, in my estimation, one of the ugliest and most fascinating of them.


Below is a photo of a deep-sea hermit crab. See those furry filaments on its claws? They are thought to be used to harvest the energy-rich chemicals infused in the pitch-black water from the methane or hydrogen sulphide seeps. Now how is that for a clever adaptation? Necessity is the mother of invention, and with no sunlight around for energy, these crabs, like many of their abyssal neighbors, have turned to the vents for sustenance. Much like how my brother and his friends seem to draw nourishment from playing Metal Gear Solid 4.


Thanks, Ida.

Photo source: NOAA via NewScientist.com

Half the Crab I Used to Be

Don't let this crustacean fool you with his crab-like appearance. You're looking at Petrolisthes elongatus, the New Zealand Half Crab. This particular specimen was found on Jetty Beach, South Bruny Island, Tasmania. What's a New Zealand creature doing on Tasmania? Good question. It's an introduced, foreign (alien?) species.

These half crabs are a variety of porcelain crab. But their name begs a question, doesn't it. What's the other half? Well, I can't find that out. My best guess is that it the other half is evil. What makes this not a true crab? For one, it's got three pairs of walking legs as opposed to the traditional four (the fourth pair of legs are used for cleaning). Lastly, this crab's abdomen can be flapped and extended (much like my own), and true crabs have no such functionality.

But I doubt the average 'true' crab walks up to a half crab and mocks it for its halfness, not with that claw action. A gargantuan version of this might be able to take Tokyo and Mothra on at the same time.

Thanks for the link, Ida.

Photo source: Nuytsia@Tas

What's in a Name

The triops is a hermaphroditic crustacean (males are very rare--a good thing for you misandrists), and is a temporary pond-dwellers. They lay eggs in these ponds, and when the ponds dry up, the eggs remain in a state of suspended animation until filled back up. Want a triops? Just take eggs and add water. Think sea monkeys.

Speaking of which, I'm surprised these critters haven't become a more popular novelty pet (they are sold as pets, but haven't caught on). I think it has to do with the name. Some clever marketer needs to come up with a better one. If you can name a shrimp a sea monkey, you can name a different crustacean just about anything you want.

Any ideas?

Thanks for the new pet, Kira.

Photo source: MyTriops.com

In a Tug Boat Cabin

Jade sent me some photos of the inhabitants of his aquariums, and when I saw these of his arrow crab, I had a flashback...

...cue harp music...

I was scuba diving down in the Sea of Cortes with a buddy of mine, and we were exploring a wreck of an erstwhile tug boat. We got down inside the cabin, and much to my horror, every corner and window sill was infested by spidery crabs just like this one, just as if the place were infested with daddy-long-legs. My arachnophobia kicked in, which was amplified by the fact that I was 50 feet underwater, wearing a constrictive wet suit, and inside a rusty chunk of metal.

It seems that spiders have forged an alliance with their crustacean cousins to haunt me wherever I go.

Thanks for helping me relive my nightmare, Jade.

I Don't Want to Grow Up

Since 1899 when these creatures were first discovered, the y-larvae has been a mystery. No one knew their adult form, or where they came from.

Scientists knew they were a crustacean, but not much more. So scientists collected a sample of more than 40 species of y-larvae (y for mystery, cue theme music). Next, they subjected this sample of y-larvae to a maturation hormone to see what they'd turn into. And guess what they found. No, not politicians:

The creatures metamorphosized into a juvenile form, dubbed "ypsigons," unexpectedly shedding their exoskeletons to become wriggling, eyeless, limbless creatures that resemble parasitic crustaceans . . . The fact that ypsigons are vastly different and far simpler than y-larvae might help explain why the adult versions of these creatures have escaped detection for so long. These are so simple compared with y-larvae that they even lack digestive tracts and nervous systems.

The working theory is that these ypsigons are essential components to any healthy reef, since they are found in every ocean from pole to pole. Though they have yet to figure out the adult form, knowing the juvenile form is a great start.

I can only imagine that y-larvae are loathe to grow up. You can't have much in the way of aspirations when you know that you'll become a wiggling, limbless, eyeless creature sans nervous and digestive systems. I see a Pixar movie in the making here: the tale of a y-larvae who wants to stay a kid.

Thanks for the article, Ida.

Photo source: Hoeg et al, BMC Biology via LiveScience.com

Crab Comparison

Here's what a normal hermit crab looks like (I used to have these as pets as a wee lad). It's something you can pick up with your finger tips. It lives in a borrowed shell. It's claws might pinch you, but it doesn't hurt.


















Here's what a coconut crab looks like. These monsters of the Indian and Pacific ocean islands have spurned the shells of their lesser cousins in favor of being able to roam and climb and kill at will. They get up to 4 kg in weight, have enormous legspans, live for 30 - 60 years, and are capable of splitting coconuts with their pinchers.

Mantis Eyes

I've posted on the mantis shrimp before (can you go wrong with a name like mantis shrimp?), and I'll post on them again. But the Bleimans have alerted me to an article in Wired that reveals whole new depths to this colorful (you'll catch the pun in a moment) creature.

Photo source: Wired
















It turns out that the mantis shrimp has spectacular eyes. For one thing, those compound eyes are composed of thousands of rows of light-detecting units called ommatidia. These ommatidia allow the mantis shrimp to see in 100,000 different colors -- that's 10 times what we humans are able to see. Wow. Crayola and the cosmetics trade would have to hire full time personnel just to create names for all their new crayons and lipsticks.

But there's more. These shrimp are the first animals ever discovered to be able to perceive circular polarized light (CPL).

Barbecue shrimp. Shrimp salad. Shrimp gumbo. CPL-seeing shrimp.

CPL is used in a variety of industries, so no doubt studying this ability in these shrimp will prove to be very valuable.

Crab Clash

Little crab tossed aside his weapons, armor, and shield in a bold challenge to big crab. But it looks like little crab forgot his sling. The Philistines might win the day.

Thanks for the photo, Ida.

Crustacean Life

Ida sent me this video of one of my favorite crustaceans: the Christmas Island Red Crab. Though these terrestrial crabs live on only two islands in the Indian Ocean, there are estimated to be around 120 million of them. This video is proof.

They are famous for their annual migration, when they emerge from their lairs to head towards the sea to breed. What's interesting is that the early records from the human inhabitants on this island hardly ever mention these crabs. It's quite possible that the extinction of the native Maclear's rat (around 1903), which would have dined on the crabs, caused their population boom.

But don't worry. A new predator has emerged to contend with the crab. The yellow crazy ant is believed to have killed more than 15 million of them in recent years. Such are the vagaries and vicissitudes of crustacean life.





Christmas Island Red Crabs - Funny video clips are a click away

Debunker Needed STAT

No. No. No, no, no, no, no.

If ever I needed one of you to be a debunker, I need you now. TELL ME this isn't real. I can't live in a world that spawns crustaceans like these.

Ida, I can't thank you for this. You may have ruined my home planet for me.

Exterior Decorator

Theodosia sent along this little crustacean. Behold the hard-to-behold decorator crab. I've encountered their ilk while scuba diving in Monterey Bay. They are really, really hard to spot (but I am incredibly observant).

I think of all the crustaceans, I am most like the decorator crab (sheesh, this blog has me doing some weird introspection). I would love to sneak around the office unnoticed, a monitor strapped to my back, 20lbs / 88 brightness paper and fax confirmations glued to my limbs, my head concealed by expired printer cartridges, paperclips, and highlighters.

But if that wish came true, there would probably be some office equivalent of the angler fish, camouflaged to look like a vending machine and dangling a pastry-shaped lure in its maw.

Photo source: Scuba Equipment USA

Chia Crab

I'm thinking, after some cursory, spotty, and incomplete research, that this is a portly spider crab.

These aren't big crabs (4 inches across the back). They inhabit estuarine waters from Nova Scotia all the way down the North American eastern seaboard, and into the Gulf of Mexico. They are known for growing a 'garden' of sponges and seaweeds on their carapace, something like a chia crab. It's the hairs on their back that attract such growth. I should warn my brother-in-law. He's furry enough to run the risk of having all sorts of denizens getting a free ride on his back.

Photo source: Antonio Guerra

Seafood Monster

The giant isopod has given me a new-found respect for rolly pollies. I've always gone out of my way to scoop up stray ones and deposit them somewhere warm and dank and decomposey. But now that I live in fear of their bigger, deep-sea-dwelling cousins, I'm extra considerate.

For you seafood enthusiasts, these critters can get to be 3 lbs, and they are often served in the Orient (like every other oddity seems to be). They have delicious white meat,very much like crab. For you horror film enthusiasts, here's your next monster.

Thanks for the photo, Danielle.

Photo source: Zoom Critic

Lobstrosity

Did-a-chick?
Dum-a-chum?
Dad-a-cham?

(for those of you who haven't read Stephen King's Dark Tower series, those questions will mean nothing to you)

You are looking at a spiny lobster (they are technically crayfish). But not just any spiny lobster--one that is five times larger than he should be (see the bottom photo).

Meet Poseidon. He was caught in a fisherman's net, but is now destined for retirement in a display aquarium. He is two feet long, and more than nine pounds in weight. That's a lot of garlic butter, my friends.

I'm going to try to hook my brother up with this woman. I'm impressed by anyone who can heft an oversized lobster and stare it down (and smile while doing so).

Article source: Daily Mail

Prepare to Feast

Below is a photo of what a splash of seawater looks like under the microscope, magnified 25 times. You're looking at a group of plankton. Now, plankton is a catch-all term for a variety of animal and plant life. Plankton is defined by its size, and by the fact that they are unable to swim against ocean currents. Plankton includes:

Marine viruses (the femtoplankton), microscopic algae and bacteria, tiny worms and crustaceans, as well as the egg, juvenile and larval forms of larger animals and plants such as seaweeds, crabs, lobsters, fish and urchins. Because they drift with ocean currents, even large jellyfish are classed as plankton.

Plankton, both plant and animal in nature, are the bread-and-butter of the oceanic food chain. And there's plenty of it. So, the next time you're in the ocean, strap on your bib, open wide, and prepare to feast.

Thanks for the link, Ida. Photo source: DailyMail

Pugnator

Ida sent this photo along. You're looking at the profile of photis pugnator. Pugnator. I'm pretty sure my siblings used to call me that.

These tiny creatures are tube-building amphipods. Amphipods are crustaceans known for their laterally compressed bodies. Think sea lice and sand fleas. Isn't that an illustrious corps of critters to belong to?

Thanks for the photo, Ida. I hadn't received my yearly dosage of amphipods yet.

Photo souce: Live Science