Meeting Abstract
All animals face an overriding constraint on their ability to produce fast movements – muscles contract slowly and over small distances. Repeatedly over evolutionary history, animals have overcome this limitation through the use of power amplification mechanisms. These mechanisms decrease the duration of movement and thereby increase speed and acceleration. The only known example of power amplification in fish is pivot feeding of the Syngnathus family, where fish are able to rotate their head upwards towards the prey at exceptionally high speeds of ~1.5 ms-1. While the mechanism for this movement is understood, our understanding of the effects of power amplification on the magnitude or spatio-temporal patters in the suction flows is limited. Furthermore, it is expected that snout length will affect the flow velocities however, there are no studies quantifying the change in spatial patterns related to snout length. Using a high-speed flow visualization technique, we characterized the spatio-temporal patterns in the flow fields produced during pivot feeding in 4 species of the Syngnathus family with a large variety of snout lengths ranging from 1.7 to 2.6 (ratio of head length to snout length). We found that the power amplification provides 8x greater flow velocities while feeding compared to other teleosts of similar size mouth diameters. We further discuss spatio-temporal changes in suction feeding performance with snout length.
