title: Escapes in copepods: comparison between myelinate and amyelinate species.
abstract: Rapid conduction in myelinated nerves keeps distant parts of large organisms in timely communication. It is thus surprising to find myelination in some very small organisms. Calanoid copepods, while sharing similar body plans, are evenly divided between myelinate and amyelinate taxa. In seeking the selective advantage of myelin in these small animals, representatives from both taxa were subjected to a brief hydrodynamic stimulus that elicited an escape response. The copepods differed significantly in their ability to localize the stimulus: amyelinate copepods escaped in the general direction of their original swim orientation, often ending up closer to the stimulus. However, myelinate species turned away from the stimulus and distanced themselves from it, irrespective of their original orientation. We suggest that faster impulse conduction of myelinated axons leads to better precision in the timing and processing of sensory information, thus allowing myelinate copepods to better localize stimuli and respond appropriately.
authors.affiliation: Marine Science Institute, 750 Channel View Drive, The University of Texas at Austin, Port Aransas, TX 78373, USA.
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Buskey
authors.affiliation: Marine Science Institute, 750 Channel View Drive, The University of Texas at Austin, Port Aransas, TX 78373, USA.|School of Freshwater Sciences, 600 E. Greenfield Avenue, University of Wisconsin-Milwaukee, Milwaukee, WI 53204, USA.
authors.forename: J Rudi
authors.initials: JR
authors.lastname: Strickler
authors.affiliation: Békésy Laboratory of Neurobiology, Pacific Biosciences Research Center, 1993 East-West Road, University of Hawaii at Manoa, Honolulu, HI 96822, USA.
authors.forename: Christina J
authors.initials: CJ
authors.lastname: Bradley
authors.affiliation: Békésy Laboratory of Neurobiology, Pacific Biosciences Research Center, 1993 East-West Road, University of Hawaii at Manoa, Honolulu, HI 96822, USA.
authors.forename: Daniel K
authors.initials: DK
authors.lastname: Hartline
authors.affiliation: Békésy Laboratory of Neurobiology, Pacific Biosciences Research Center, 1993 East-West Road, University of Hawaii at Manoa, Honolulu, HI 96822, USA petra@hawaii.edu.
authors.forename: Petra H
authors.identifier: 0000-0002-2460-5464
authors.initials: PH
authors.lastname: Lenz
mesh_terms: D000818:Animals; D001369:Axons / Q000378:metabolism; D033342:Copepoda / Q000502:physiology*; D004924:Escape Reaction; D005260:Female; D009186:Myelin Sheath / Q000378:metabolism*
keywords: Calanoida; Escape direction; Myelin