The larvae of dragonflies squirt water out their anuses to lunge forward after prey thanks to hydraulic linkages.
"Hydraulic linkages occur in a wide variety of biological systems…In addition, one can point to the predatory strike of dragonfly larvae, which lunge forward by squirting water out their anuses (Tanaka and Hisada 1980)…" (Vogel 2003:420-421)
Learn more about this functional adaptation.
- Steven Vogel. 2003. Comparative Biomechanics: Life's Physical World. Princeton: Princeton University Press. 580 p.
- Tanaka, Y; Hisada, M. 1980. The hydraulic mechanism of the predatory strike in dragonfly larvae. Journal of Experimental Biology. 88: 1-19.