Meeting Abstract
S4.8 Wednesday, Jan. 5 Sensory perception, behavioral adaptations and the neuroecology of predator avoidance in planktonic copepods BUSKEY, E.J.*; LENZ, P.H.; HARTLINE, D.K.; GEMMELL, B.; BRADLEY, C.; SHENG, J.; STRICKLER, J.R.; University of Texas at Austin; University of Hawaii; University of Hawaii; University of Texas at Austin; University of Hawaii; University of Minnesota; University of Wisconsin, Milwaukee ed.buskey@mail.utexas.edu
Copepods are important grazers on microplankton in marine food webs and are, in turn, preyed upon by a wide range of predators with diverse feeding adaptations, including ambush-entangling predators such as jellyfish and active raptorial predators such as fish. Although copepods have evolved a wide range of adaptations to help them avoid predation, their escape behavior sets them apart from many other planktonic organisms. Mechanoreception is widely used by copepods to detect hydrodynamic disturbances created by approaching predators. When these disturbances are detected, copepods respond quickly with escape jumps that accelerate them from a stationary position to speeds of over 600 body lengths per second within a few milliseconds. Using model predators, high-speed video and digital holographic techniques, the ability to avoid predation has been examined for both myelinated and non-myelinated species of copepods. Myelinated nerves may improve the escape behavior of some copepods through faster conduction of nerve impulses. The differences in responses latencies between myelinated and non-myelinated copepod species are greatest for large copepod species, where nerve signals must be conducted over longer distances. In smaller copepod species, myelinated nerves may allow for more precise spatial location of hydrodynamic disturbances. Myelinated nerves are found in the more recently evolved superfamilies of copepods, but not the more basal groups. Myelinated copepods may have adaptive advantages in habitats dominated by raptorial predators, while amyelinated groups may have evolved other effective anti-predator adaptations.
