Snapping shrimps: Females more aggressive than males

By Michelle WarwickerBBC Nature

Female snapping shrimps are more aggressive than males, frequently snapping their deadly claws at each other, a study has shown.

Researchers in the US had expected male shrimps - which brandish a larger snapping claw - to behave more aggressively.

But despite their smaller claw size, females snapped more often when defending their territory.

Findings are published in the journal Ethology.

"We're so used to seeing animals in which males have larger weapons than females: bigger antlers, bigger teeth, bigger horns... And in many of these species, males are more aggressive than females," said Dr Melissa Hughes, from the College of Charleston in South Carolina, US who led the study.

"Males, more so than females, benefit from being aggressive and having large weapons, in species where males compete for females."

Snapping shrimps are sometimes called pistol shrimps and use their larger claw - the major chela - as a deadly weapon to kill prey and opponents.

They can kill enemies with a direct snap, and are known to stun potential food with a jet of bubbles by rapidly closing their larger claw. The snapping sound of this bubble blast collapsing gave the animals their name.

The researchers wanted to see how different sexes use their claws to defend their territory.

Continued