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.


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 . . .
ROCK OUT WITH THEIR COCK OUT!!! Yeah baby!!