The toolkit of a hunter – functional morphology of larval mouthparts in a dragonfly

Abstract

AbstractThe diversity of mouthpart specializations in insects is staggering. As a direct consequence thereof, the knowledge about the mouthpart geometry, muscle attachment and feeding kinematics is incomplete for the vast majority of insect taxa – as it is for dragonflies. The adult dragonflies catch their prey in flight, while the aquatic larvae prey under water – both life stages being key predators in their biotopes. To gain insights into the functional morphology of the biting‐chewing mouthparts of larval Anax imperator, we combined results from micro computed tomography (µCT), confocal laser scanning microscopy (CLSM) and high‐speed videography. Anax imperator larvae were filmed during the feeding process to describe the movement and coordination of the mouthparts. These results, together with µCT‐data, allowing for a comprehensive visualization of the 3D‐geometry and corresponding musculature of each mouthpart. The material composition of the cuticle strongly influences the strength, mobility and durability of the cuticular components of the mouthparts. With this paper, we elucidate the anatomy, geometry and material composition of A. imperator's larval mouthparts in the light of the feeding process. Furthermore, we try to lay a foundation for functional morphological comparisons of mouthparts (1) between dragonfly species belonging to different eco‐types according to their food preferences and feeding habits or even (2) between different insect groups.