University of California Santa Barbara, Ph.D. (Biology)
University of California Santa Barbara, M.A. (Biology)
University of California San Diego, B.A. (Biology)
Planktonic organisms inhabit a world populated with predators but offering few places to hide. Despite this hostile environment, pelagic copepods are among the most successful of all marine metazoans. How did this come to be? Using electrophysiological and behavioral approaches, we demonstrated that a key piece to the puzzle lies in the extremes in predator-evasion capabilities evolved by the group: high mechanosensitivity, short response latencies, rapid conduction of nerve impulses (by myelin in some species), and exceptional escape speeds (Hartline et al 1996; Lenz and Hartline 1999; Davis et al 1999; Burdick et al 2007). Current work has focused on quantifying predator-prey interactions in order to better understand how these sensorimotor adaptations of the copepod affect escape success. We have established that copepods are capable of swimming at a 10x-faster rate than equivalently-sized predators, or in other words, a copepod can out-swim a predator that is 10 times its size (in body lengths; 1000 in mass), and this relation holds for a range of copepod sizes and developmental stages (Bradley et al 2013). Investigating how such performance extremes benefit the organism, we have found that the survivorship and escape characteristics of calanoids depend on the competence, and in particular the developmental stage, of the predator as well as the prey. Adult reef fish almost always succeed in capturing copepods (Buskey et al. 2012), so the escape performance of the copepod is of little selective value. However for younger (and in general more numerous) larval fishes the tables are turned and copepod escape performance becomes quite significant.
Christie, A.E., Roncalli, V., Wu, L.-S., Garrote, C.L., Doak, T. andLenz, P.H. (2013). Peptidergic signaling in Calanus finmarchicus (Crustacea: Copepoda): in silico identification of putative peptide hormones and their receptors using a de novo assembled transcriptome. General and Comparative Endocrinology, in press.
Jungbluth, M.J. and Lenz, P.H. (2013). Copepod diversity in a subtropical bay based on a fragment of the mitochondrial COI gene. Journal of Plankton Research, available online
Bradley, C.J., Strickler, J.R., Buskey, E.J. and Lenz, P.H. (2013). Swimming and escape behavior in two species of calanoid copepods from nauplius to adult. Journal of Plankton Research, 35:49-65.
Christie, A.E., Roncalli, V., Batta Lona, P., McCoole, M.D., King, B.L., Bucklin, A., Hartline, D.K. and Lenz, P.H. (2013). In silico characterization of the insect diapause-associated protein couch potato (CPO) in Calanus finmarchicus (Crustacea: Copepoda). Comparative Biochemistry and Physiology. Part D, Genomics & Proteomics, 8:45-57.
Buskey, E.J., Lenz, P.H. and Hartline, D.K. (2012) Sensory perception, neurobiology, and behavioral adaptations for predator avoidance in planktonic copepods. Adaptive Behavior, 20:57-66