Meeting Abstract
The extreme impact forces and dramatic displays delivered by fighting mantis shrimp (Stomatopoda) are an exceptionally dynamic example of weapon use. While knowledge of weapon systems is based mainly on weapons that exert low peak forces over milliseconds, mantis shrimp strikes exert high peak forces over microseconds. Classic predictions of weapon systems – that weapon morphology correlates with weapon force, weapon displays reliably signal weapon force, and winners of fights have greater weapon force – have yet to be tested in the ultrafast, high-peak force weapons of mantis shrimp. We tested these predictions by studying sex- and size-matched fights in Neogonodactylus bredini. Weapon morphology did not correlate strongly with maximum strike force. Additionally, the ‘meral spread’ weapon display of N. bredini was not more common than other behaviors, and few fights were concluded by meral spreads alone. Winners of fights did not have greater maximum strike force than losers; instead, winners struck a greater number of times during fights than losers. While most fights escalated to striking, strikes were often delivered onto the armored tailplate (telson) of competitors and caused no significant damage. Our results indicate that meral spreads in N. bredini do not communicate maximum strike force. Instead, we propose that telson striking may signal an individual’s aggressive persistence or energetic capabilities during a fight. By testing classic weapon predictions in an ultrafast weapon system, we show that what is commonly known as combat (exerting force onto competitors) may not be damaging, but instead may signal another aspect of fighting ability.
