There’s no place like the perfectly sized home for the mighty mantis shrimp

"Nice burrow you have there. I want it." Patrick Green of the University of Exeter filmed this fight between mantis shrimp. (video link)

Size matters to the small-but-mighty mantis shrimp, which show a marked preference for burrows in coral rubble with volumes that closely match their own body size or are just a bit larger—in other words, large enough to accommodate their body, but small enough that they can defend the entrance. But according to a new paper published in the journal Animal Behavior, sometimes a mantis shrimp will compromise. If a burrow is already occupied and is close to the ideal size, or a bit smaller, the mantis shrimp will fight longer and harder for that burrow—and be more likely to win the contest.

As we previously reported, mantis shrimp come in many different varieties: there are some 450 known species. But they can generally be grouped into two types: those that stab their prey with spear-like appendages ("spearers") and those that smash their prey ("smashers") with large, rounded, and hammer-like claws ("raptorial appendages"). Those strikes are so fast—as much as 23 meters per second, or 51mph—and powerful, they often produce cavitation bubbles in the water, creating a shock wave that can serve as a follow-up strike, stunning and sometimes killing the prey. Sometimes a strike can even produce sonoluminescence, whereby the cavitation bubbles produce a brief flash of light as they collapse.