Meeting Abstract
Power amplifying “trap-jaws” have evolved independently multiple times in ants, making them ideal for research on comparative biomechanics and on the relationship between form and function. However, most research on trap-jaw ants has focused on a single group and the remaining independent origins of trap-jaws have not been studied in detail. We used high speed videography and micro CT to describe the strike kinematics and functional morphology of miniature trap-jaw ants (Strumigenys spp.). We examined 15 species of Strumigenys chosen to represent morphological and phylogenetic diversity. We found a large amount of variation in morphology and performance among species in properties such as body size, mandible length and shape, bite gape, rotational velocity, and power output. Like other trap-jaw ants, Strumigenys have some of the fastest predatory movements known in the animal kingdom, with strikes of some species occurring in less than 0.006 ms and reaching maximum linear velocities greater than 60 m/s. Based on power output, we determined that not all species of Strumigenys possess power amplifying mandibles, and that power amplification has independently evolved at least 3 times within this genus. Strike performance scales with body size in a similar manner to scaling relationships seen in other trap-jaw groups. Results from micro CT scans show a high degree of morphological convergence between muscle arrangements in groups that have evolved power amplification mechanisms. Future work will focus on large scale comparisons between Strumigenys and other independent origins of power amplification mechanisms in ants.
