J. Exp. Mar. Biol. Ecol., 162 (1992) 15-33 © 1992 Elsevier Science Publishers BV. All rights reserved 0022-0981/92/$05.00 15 JEI~.BE 01819 The effects of geography and hurricane disturbance on a tropical predator-prey interaction Richard B. Aronson Department of Invertebrate Zoology, National Museum of Natural History, Smithsonian lnstituti.~i, Washington, District of Columbia, USA; Institute of Marine and Coastal Sciences, Rutgers University, New Brunswick, New Jersey, USA (Received 9 March 1992; revision received 28 April 1992; accepted 5 May 1992) Abstract: Temperate-tropical predation comparisons require estimates ofthe variability ofpredation intensity within those climatic zones. Latitudinal comparisons are possible only if predation is consistent within lo- calized areas. This study investigated two aspects of predation intensity experienced by the Caribbean ophiuroid Ophiothrix oerstedi LOtken within and among back reef sites in Jamaica, St. Croix, Barbados, and Belize. Predation potential, the propensity of predators to consume prey, was measured experimenl ally as the mortality of tethered ophiuroids. Predation pressure, the natural frequency of predator-prey encounters, was measured as the frequency of sublethal damage: the proportion of ophiuroids regenerating one or more arms. Daytime and nighttime predation potentials were clustered by site, not by season, year, or temporal relationship to hurricane events. Daytime predation potential was positively correlated with the abundance of predatory fishes (wrasses). Although the abundance of nocturnal predators did not vary significantly among sites, among-site differences in species composition partially explained the observed differences in nighttime predation potential. There were neither significant among-site differences, nor within-site tempo- ral patterns, in the frequency of sublethal arm damage in O. oerstedi populations. Strong hurricanes did not increase arm damage frequencies at Jamaica or St. Croix, implying that few injuries are caused by storms. The consistency of predation potential on O. oerstedi within sites suggest that latitudinal comparisons will be possible with ophiuroids. Key words: Coral reef; Hurricane; Latitudinal gradient; Ophiuroid; Pisces; Predation INTRODUCTION The hypothesis that predator-prey escalation has progressed to a greater degree at lower latitudes is one of the guiding principles of marine biogeography (Vermeij, 1978; but see Jones etal. (1991) for objections). This generalization is derived from temperate-to-tropical trends of increased abundance, increased activity, greater skeleton-crushing capability, and greater resistance to chemical defense in consumers, as well as trends of increased antipredator architecture, higher frequencies of sublethal damage, increased toxicity, and increased refuging behavior in prey (e.g., Bakus & Green, 1974; Vermeij, 1978; Palmer, 1979; Bertness et al., 1981; Menge & Lubchenco, 1981; Gaines & Lubchenco, 1982; Lowell, 1987; Duffy & Hay, 1990; Choat, 1991). Correspondence address: R.B. Aronson, Department of Invertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560, USA.