Mar Biol (2007) 152:129–133 DOI 10.1007/s00227-007-0669-1 123 RESEARCH ARTICLE Scarred limpets at hydrothermal vents: evidence of predation by deep-sea whelks Janet R. Voight · Julia D. Sigwart Received: 9 January 2007 / Accepted: 1 March 2007 / Published online: 3 April 2007  Springer-Verlag 2007 Abstract The chaotic physical and chemical environment at deep-sea hydrothermal vents has been associated with an ecosystem with few predators, arguably allowing the habitat to provide refuge for vulnerable species. The dominance of endemic limpets with thin, open-coiled shells at north PaciWc vents may support this view. To test their vulnerabil- ity to predation, the incidence of healed repair scars, which are argued to reXect non-lethal encounters with predators, were examined on the shells of over 5,800 vent limpets of Lepetodrilus fucensis McLean (1988) that were collected from 13 to 18 August 1996. Three vent Welds on the Juan de Fuca Ridge at ca. 2,200 m depth were sampled, two within 70 m of 47°56.87'N 129°05.91'W, and one at 47°57.85'N 129°05.15'W with the conspicuous potential limpet preda- tors, the zoarcid Wsh Pachycara gymninium Anderson and Peden (1988), the galatheid crab Munidopsis alvisca Williams (1988), and the buccinid snail Buccinum thermo- philum Harasewych and Kantor (2002). Limpets from the predator-rich vent were most often scarred, a signiWcant diVerence created by the high incidence of scars on small (<4 mm long) limpets in this sample. Collected with the lim- pets were small (median shell diameter 4.4 mm) buccinids. They, rather than the larger, more conspicuous mobile Wshes and crabs are argued to be the shell-damaging predator. Introduction Biological systems at deep-sea hydrothermal vents support comparatively few species in extremely high densities (Tsurumi and TunnicliVe 2001). Given the physical and chemical extremes characteristic of the vent habitat, endemic taxa dominate. Although the chemosynthetic processes that fuel these systems have been well studied, trophic interactions among vent heterotrophs remain largely unknown. Predators had been suggested to be rare at these systems (e. g. Cohen and Haedrich 1983; Turner 1985; Cohen et al. 1990), although crabs, Wshes, predatory snails and octopuses occur near and even within vent eco- systems (TunnicliVe 1991; Voight 2000). Recent studies suggest that predation aVects species diversity at vents on the East PaciWc Rise (Micheli et al. 2002); analysis of gut contents reveals that the zoarcid Wsh, Thermarces cerberus, preys heavily on vent limpets at East PaciWc Rise vents (Sancho et al. 2005). At north PaciWc vents, however, the endemic limpet Lepetodrilus fucensis appears to lack com- parable predators (Tsurumi and TunnicliVe 2003). Among the most common animals at these vents (Tsurumi and TunnicliVe 2001, 2003), these limpets reach astounding densities of up to 2,100 per dm 2 (Bates et al. 2005). Communicated by J.P. Grassle. Electronic supplementary material The online version of this article (doi:10.1007/s00227-007-0669-1) contains supplementary material, which is available to authorized users. J. R. Voight (&) Field Museum of Natural History, 1400 S. Lake Shore Drive, Chicago, IL 60605, USA e-mail: jvoight@Weldmuseum.org J. D. Sigwart Illinois Mathematics and Science Academy, Aurora, IL, USA Present Address: J. D. Sigwart Natural History Division, National Museum of Ireland, Merrion Street, Dublin 2, Ireland