Whelks induce an effective defense against sea stars

Abstract

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 493:195-206 (2013) - DOI: https://doi.org/10.3354/meps10501 Whelks induce an effective defense against sea stars Benjamin G. Miner1,2,*, Deborah A. Donovan1,2, Lisa M. Portis2,3,4, Tricia C. Goulding2,5,6 1Western Washington University, Biology Department, Bellingham, Washington 98225, USA 2Shannon Point Marine Center, Anacortes, Washington 98221, USA 3Colby College, Waterville, Maine 04901, USA 4Atlantic Ecology Division, U.S. Environmental Protection Agency, Narragansett, Rhode Island 02882, USA 5University of California, Santa Barbara, California 93106, USA 6Pennsylvania State University, University Park, Pennsylvania 16802, USA *Email: benjamin.miner@wwu.edu ABSTRACT: The whelk Nucella lamellosa displays phenotypic plasticity in the presence of the sea star Pisaster ochraceus by becoming more retractable. In this study, we directly tested whether this response is an inducible defense, and looked for evidence of phenotypic costs associated with the induced phenotype. We found that whelks held in the presence of sea stars consuming conspecific whelks became more retractable, while whelks that were not exposed to sea stars became less retractable—indicating that this is a reversible and symmetric (i.e. similar magnitude of change) response. We did not find changes in aspect ratio of the shell or size of the whelks. Following the induction experiment, whelks were fed to sea stars. In this predation experiment, sea stars were much less likely to consume whelks previously exposed to sea stars compared to whelks not exposed to sea stars. There was a strong relationship between mortality and retractability relative to shell length, and individuals that could retract 50% of their shell length had relatively little chance of being consumed during the predation experiment. These results support the hypothesis that increased retractability is an inducible defense. We also conducted field surveys of N. lamellosa populations and found differences in retractability among populations, most of which were more retractable than the whelks in our induction experiment. For these field-collected individuals, we found evidence of phenotypic costs, with a negative relationship between retractability and tenacity. Thus, N. lamellosa responds to a sea star predator by becoming more retractable but at the cost of becoming less tenacious. KEY WORDS: Inducible defenses · Nucella lamellosa · Predation · Phenotypic plasticity · Pisaster ochraceus · Retractability · Sea star · Whelk Full text in pdf format Supplementary material PreviousNextCite this article as: Miner BG, Donovan DA, Portis LM, Goulding TC (2013) Whelks induce an effective defense against sea stars. Mar Ecol Prog Ser 493:195-206. https://doi.org/10.3354/meps10501 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 493. Online publication date: November 20, 2013 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2013 Inter-Research.