Tiny Shrimp Terrorizes Aquarium

Jan. 5 -- They may be shrimps, but they pack a powerful punch.

The so-called smasher variety of the mantis shrimp attacks by whamming down the lower edge of its dull, calcified claw with such speed, it’s enough to pulverize a snail’s shell, smash out chunks of a rock wall or even break a finger.

Now a smasher mantis shrimp is wreaking havoc in a family exhibit of splash zone species at the Monterey Bay Aquarium in California. Hermit crabs, snails and barnacles, which all help filter algae from the tanks and keep them clean, are disappearing daily by the handful. Two small fire fish also disappeared recently, casting more suspicion on the furtive, 3 ½-inch-long smasher.

First There Were Two

“We’ve seen two, and in November we caught one. So we know there’s one left out there,” says David Snipe, an aquarist at the Monterey aquarium. “It makes a pretty big snapping sound when it’s knocking off the snails or hermit crabs, so we know when it strikes.”

Roy Caldwell, a professor of integrative biology and a mantis shrimp specialist at the University of California at Berkeley has identified the pesky aquarium shrimp as a small variety of a smashing stomatopod. Other stomatopods, known as spearers, attack by using their sharp, formidable claws like blades. These “thumb-splitters” can cut through a person’s finger in milliseconds.

The smasher’s claws may be duller, but Caldwell explains, they’re equally effective — especially when attacking a shelled creature.

“I got a letter from a surgeon once in South Africa who was diving and saw a 10-inch long smasher,” Caldwell recalls. “When he tried to grab it, it so severely damaged his finger that they had to amputate.”

Arrived by Rock

Snipe says the lone mantis shrimp in the Splash Zone exhibit at Monterey Bay Aquarium likely arrived as a hitchhiker early last year within rocks or coral the museum imported from Florida and Figi.