Thresher sharks use tail-slaps as a hunting strategy

Area of Science:

• Marine Biology
• Animal Behavior
• Ichthyology

Background:

• Thresher sharks' hunting methods, particularly tail use, remain poorly understood in the wild.
• The kinematics of tail-slapping behavior in pelagic thresher sharks (Alopias pelagicus) require detailed investigation.

Purpose of the Study:

• To investigate and document the hunting strategies of pelagic thresher sharks.
• To analyze the kinematics and effectiveness of tail-slapping as a hunting technique.

Main Methods:

• Observations of thresher sharks were conducted using handheld underwater video cameras.
• 61 hunting events were recorded, with 25 tail-slapping events analyzed in detail.

Main Results:

• Thresher sharks utilize tail-slaps to debilitate sardines throughout the day and night.
• Hunting involves distinct phases: preparation, strike, recovery, and prey collection.
• Tail-slaps are initiated by pectoral fin adduction, causing a rapid posterior lift and stall.

Conclusions:

• Tail-slapping is a highly effective foraging strategy for thresher sharks, enabling consumption of multiple prey.
• Specialized pectoral and caudal fins in Alopiids likely evolved for tail-slapping.
• Thresher sharks hunt opportunistically, potentially increasing vulnerability to fisheries.