Feeding behaviour of an intertidal snail: Does past environmental stress affect predator choices and prey vulnerability? Ignacio Gestoso a, ⁎, Francisco Arenas b , Celia Olabarria a a Departamento de Ecoloxía y Bioloxía Animal, Universidade de Vigo, 36310 Vigo, Spain b CIIMAR — Centro Interdisciplinar de Investigação Marinha e Ambiental, University of Porto, Rua dos Bragas 289, 4050-123 Porto, Portugal abstract article info Article history: Received 22 June 2014 Received in revised form 12 December 2014 Accepted 19 December 2014 Available online xxxx Keywords: Predator–prey interaction Climate change Nucella lapillus Xenostrobus securis Mytilus galloprovincialis Non-indigenous species Predation is one of the most important factors in determining structure and dynamics of communities on inter- tidal rocky shores. Such regulatory role may be of special relevance in novel communities resulting from biolog- ical invasions. Non-indigenous species frequently escape natural predators that limit their distribution and abundance in the native range. However, biological interactions also can limit the establishment and spread of non-native populations. There is a growing concern that climate change might affect predator–prey interactions exacerbating the ecological impacts of non-indigenous species. However, mechanisms underlying such interac- tions are poorly understood in marine ecosystems. Here, we explored if past environmental stress, i.e., increasing temperature and decreasing pH, could affect the vulnerability of two mussel prey, the native Mytilus galloprovincialis and the non-indigenous Xenostrobus securis, to predation by the native dogwhelk Nucella lapillus. In addition, we evaluated the consequences on the feeding behaviour of N. lapillus. First, we exposed monospe- cific assemblages of each mussel species to combined experimental conditions of increasing temperature and decreasing pH in mesocosms for 3 weeks. Then assemblages were placed on a rocky shore and were enclosed in cages with dogwhelks where they remained for 3 weeks. Despite the lack of preference, consumption was much greater on the native than on the invasive mussels, which barely were consumed by dogwhelks. However, this trend was diverted when temperature increased. Thus, under a coastal warming scenario shifts in dogwhelks feeding behaviour may help to contain invader's populations, especially in estuarine areas where these predators are abundant. © 2014 Elsevier B.V. All rights reserved. 1. Introduction On intertidal rocky shores, patterns of distribution of species are de- termined by complex interactions between biological and physical forces (Connell, 1961). Among these forces, predation is one of the most important factors in determining structure and dynamics of communities (Menge, 1983; Wieters and Navarrete, 1998). The most evident effect of predation encompasses changes on prey density and distribution limits, while indirectly it can change diversity within the community (Sih et al., 1985; Wieters and Navarrete, 1998). Neverthe- less, the effect of predators on prey populations often varies in intensity across space and time due to different factors, e.g., variation in predator densities at population level, indirect interactions, differential foraging efficiency, or feeding preferences (Hines et al., 2009; López et al., 2010; Menge, 1983; Shinen et al., 2009). The regulating role of predators is of special relevance in novel com- munities resulting from the establishment of non-indigenous species (NIS) (López et al., 2010; Rilov, 2009; Rodriguez, 2006; Shinen et al., 2009) since a number of complex novel interactions can be established due to the arrangement of new set of species. For instance, native predators can facilitate invasion of a NIS via consumption of native com- petitors if they fail to recognize a novel species as a potential prey (Keane and Crawley, 2002). Alternatively, strong preferences for NIS may release native species from potential new competitors or enemies (Rodriguez, 2006), or open the possibility of novel responses, such as as- sociational susceptibility or defence within a community (Shinen et al., 2009). Feeding preferences can determine to a great extent, both the per individual and the total effect of predators on prey assemblages invaded by NIS. Thus how predators choose their diets and hunting efficiency are crucial to our understanding of predator–prey interactions, particularly with regard to stabilizing properties (Sih, 1987). Knowing whether or not predator behaviour is caused by preference might also help ecolo- gists to understand how predator–prey interactions may be modulated by environmental changes (Jackson and Underwood, 2007). Predator food preference is a combination of characteristics of both the predator and the prey traits (e.g., prey size, prey vulnerability, prey quality or profitability, handling time, availability or the past expe- rience of the predator and prey) (Hughes and Dunkin, 1984a; López et al, 2010; Munari and Mistri, 2011). The vulnerability or ability of a prey species to avoid predation may be also conditioned by physical Journal of Sea Research xxx (2015) xxx–xxx ⁎ Corresponding author at: Edificio de Ciencias Experimentales, Campus Universitario de Vigo, 36310 Vigo (Pontevedra), Spain. Tel.: +34 670043632. E-mail address: ignaciogestoso@uvigo.es (I. Gestoso). SEARES-01327; No of Pages 9 http://dx.doi.org/10.1016/j.seares.2014.12.006 1385-1101/© 2014 Elsevier B.V. All rights reserved. Contents lists available at ScienceDirect Journal of Sea Research journal homepage: www.elsevier.com/locate/seares Please cite this article as: Gestoso, I., et al., Feeding behaviour of an intertidal snail: Does past environmental stress affect predator choices and prey vulnerability?, J. Sea Res. (2015), http://dx.doi.org/10.1016/j.seares.2014.12.006