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Next article FreeAbout the CoverFull TextPDF Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinked InRedditEmailQR Code SectionsMoreCoverAn adult northeastern Pacific hagfish (Eptatretus stoutii) rests in a counterclockwise coiling posture. Being jawless, boneless, and sightless, hagfish (Myxinoidea) have an origin closely related to that of vertebrates, and thus are likely retain some primitive features. Because of this important phylogenetic position, hagfish occupy a special place in zoological research as a potential probe of ancestral vertebrate conditions. However, their behaviors are poorly understood. Hagfish exhibit several curious and unique behaviors, such as producing copious amounts of slime when disturbed; ability to tie themselves into a knot that slides along the body (a “traveling knot”); and, at least in this genus (Eptatretus spp.), coiling in a tight spiral when at rest. Anecdotal reports of clockwise and counterclockwise orientations are known from the wild and captivity, but this unusual behavior has not been studied systematically.Miyashita and Palmer (pages 111–120 of this issue) investigated the coiling behavior in E. stoutii to test whether hagfish are “handed”— that is, coil in one direction more frequently than expected due to chance. Individual hagfish do prefer to coil in either a clockwise or counterclockwise orientation. However, no significant bias was evident at the population level. That is, clockwise and counterclockwise coiling were equally likely when all individuals were pooled. Such handedness at the individual—but not population—level implies that preferred coiling orientation is not determined genetically. Instead, individual hagfish likely develop an initial preference for coiling in one orientation that is reinforced via repeated coiling in that direction.Many vertebrates with an elongate trunk also coil, and invertebrate chordates have many potentially lateralized behaviors. Miyashita and Palmer reviewed these behaviors to test whether coiling behaviors in vertebrates might have a shared origin, and whether any lateralized behavior can be inferred for the last common ancestor of living vertebrates. The resulting synthesis suggests that coiling behaviors in various vertebrates, and asymmetric behaviors in invertebrate chordates, evolved independently in each lineage. However, many of these behaviors remain to be systematically investigated. Miyashita and Palmer's analysis of hagfish coiling serves as a guideline for future comparisons of potentially lateralized behaviors in vertebrates and their relatives. It also affirms quite strongly that no population-level handed behavior is evident in this ancient vertebrate lineage, in contrast to reports of such behaviors in other fish.Credits: Photo by Tetsuto Miyashita, University of Alberta; cover design by Beth Liles, Marine Biological Laboratory. Next article DetailsFiguresReferencesCited by The Biological Bulletin Volume 226, Number 2April 2014 Published in association with the Marine Biological Laboratory Article DOIhttps://doi.org/10.1086/BBLv226n2cover Views: 103 © 2014 by Marine Biological Laboratory. All rights reserved. Crossref reports no articles citing this article.