Another Blow to Sea Cucumbers and a New Challenger to the Ring

Ed Yong over at Not Exactly Rocket Science ha an awesome post highlighting recent research on the unique vision of mantis shrimps. At the end of his post he (rightfully) dismisses the sea cucumber:

“Personally, I think mantis shrimps kick the crap out of sea cucumbers, but they’re on a par with squid, which incidentally also use polarised light for secret communication.”

This makes me slightly conflicted as someone who is describing a new species shrimp. Really, I love all the invertebrates, but like any well-meaning parent with a gazillion children, I certainly have a few that are favorites. Certainly I have a love of all things crustacean. I am calling on all readers to head over to Ed Yong’s post and see the awesome video at the end of his post showing a mantis shrimp kicking the hell out of everything that walks in front of it! That clicking sound you hear? The force of a mantis shrimp closing its claw is so great it sends out a stream of water that hits the glass side of the aquarium and makes the little ping sounds. They are also known as snapping shrimp or pistol shrimp if I am not mistaken.

So we have several champions out there. Craig has made his stand on mollusks, PZ is the purveyor of Cephalopods, Sheril threw down with the sea cucumber, Jim Lemire supports Sea Urchins, Jbyrnes is the maestro of Tunicates and now Ed throws in his glove for the mantis Shrimp. Peter has yet to take a stance and though I supported Craig’s earlier move with the mollusks, I may have to break away with the organism that really got me into studying marine invertebrates: the Barnacle! Especially stalked barnacles. Below is a poster from a newspaper by Sam Hinton in 1981 of Neolepas zevinae. Neolepas (new shellfish) was the species that gave me my first experience with stalked barnacles.


In life:

Neolepas%20zevinae.jpgPhoto: Peter Batson/Image Quest Marine

What is so cool about barnacles anyways? They are the John Holmes of the invertebrate kingdom with penis lengths exceeding 8 times their body length. When ready to become adults, they settle out of the water column and glue their heads to a rock or shell and secrete a calcified shell to protect it (unique among crusteceans), complete with movable plates. Their cirri, or feeding appendages (see photo above), are often long and silky, quite elegant, but are actually the “legs” of the barnacle. Imagine your self glued head first to a rock, kicking your legs out your front door to draw in a current, hopefully with food – that is the barnacle. They are prolific, inhabiting anything with a hard substrate, including boats, docks, shells and even other critters like whales and sea turtles. Some are able to burrow into shells, corals and sediment. Others infect crabs and hijack their reproductive system. They even have a unique larval stage, the cypris (see picture below, courtesy Wim van Egmond).


The barnacles were also monographed by none other than the Charles Darwin. His four tomes on the Cirripedia (curled-foot) cemented his authority to wax poetic on their origin. In effect, the unassuming barnacles, while perhaps the lesser charismatic of the invertebrates, holds a lot of secrets and quite literally . . .

(Hat tip to Oysters Garter)


10 Replies to “Another Blow to Sea Cucumbers and a New Challenger to the Ring”

  1. That may settle it. I must admit the John Holmes of Invertebrates has appeal. But mantis shrimps? Don’t they break things with a cavitating hammer? Kind of like Thor? I am going to have to check that out.

    You don’t expect me to vote for corals, do you? Primitive colonies of lazy suspension feeding polypoid clones… really, I mean, its almost embarassing.

  2. “Don’t they break things with a cavitating hammer? Kind of like Thor?”

    That’s just… brilliant. I’m going to steal that in the future. Big thanks to Kevin for the nod. One quick point though: snapping/pistol shrimps are different but equally cool and they also produce a cavitation wave.

  3. I think pistol shrimp are generally considered to be members of the genus Alpheus, which can also kill things by shock wave.

  4. Except that anthozoans have collectively built the largest living structures on earth, the reefs. These in turn provide the heterogeneous niches on which so many other inverts depend. Wish I could secret a house just by sitting on my butt. :)

  5. LOL at the barnacle info. Who knew?

    Crustaceans kick carapace, especially the Malacostracans, IMO. But I’d have a hard time choosing a favorite marine invertebrate group, since I’m the excitable sort who nearly fell off the dock into very cold water, the first time I used a submersible light. Glad someone grabbed my jacket when a squid swam by, or I would have gone headfirst into the drink.

    In the Cnidarian category, I’d back a Portuguese man-o’-war or a box jelly, in a fair fight.

  6. Mantis shrimp and pistol shrimp are different critters. Pistol shrimp use a shockwave from a claw to hunt. Mantis shrimp (known in some parts as “thumb-splitters”) actually spear their prey with their front limbs. They are fast enough to cause cavitation but that’s not the primary method of hunting.

    I spoke to fishermen who saw men’s hands pierced through by mantis shrimp, so they get my vote.

    The preview isn’t showing my photo, so here’s a link for a Thai mantis shrimp. scary, and delicious. the perfect combination.

  7. Mantis shrimp might get my vote (although “barnacle envy” was recently heard within my lab). Two small points:

    1) Mantis shrimp have both “spearer” species (feed on fishes and soft things) AND “smasher” species (feed on shellfish), each with appropriately shaped claws. Apparently, some smashers also have sharp edges to their claws that they can use while swimming, getting the best of both worlds, I suppose.

    2) I’ve personally seen the monster mantis shrimp in Bangkok live-fish restaurants, but the Squilla empusa species in the Chesapeake Bay is much more blandly colored and small. Another distinction is that this species tastes an awful lot like mud. Pick your pissing shrimp species with care!

  8. Yeah the snapping shrimp are in the Alpheus. If it wasn’t for the mimic octopus they would be my favorite invert cause you know they evolved to have a gun for a claw.

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