Predator chemical cues affect prey feeding activity differently in juveniles and adults

Abstract

Nonconsumptive predator effects on prey behaviour are common in nature, but the possible influence of prey life-history stage on such responses is poorly known. We investigated whether prey life-history stage may be a factor affecting prey feeding activity responses to predator chemical cues, for which we used dogwhelks (Nucella lapillus (L., 1758)) and their main prey, barnacles (Semibalanus balanoides (L., 1758)), as a model system. Barnacles use their modified legs (cirri) to filter food from the water column. Through a manipulative laboratory experiment, we tested the hypothesis that the presence of dogwhelks affects the frequency of leg swipes differently in juvenile and adult barnacles. Juveniles showed a similar feeding activity with and without nearby dogwhelks, but adults exhibited a significantly lower frequency of leg swipes when dogwhelks were present. Such an ontogenetic change in the response of barnacles to predatory cues might have evolved as a result of dogwhelks preferring adult barnacles over juvenile barnacles, as found previously. Alternatively, barnacles could learn to recognize predator cues as they age, as shown for other prey species. Overall, our study indicates that the nonconsumptive effects of predators on prey need to be fully understood under consideration of the possible ontogenetic changes in prey responses to predator cues.Résumé : Les effets des prédateurs, autres que la consommation de la proie, sur le comportement des proies sont courants en nature, mais l'influence possible du stade du cycle biologique de la proie sur ces effets reste mal connue. Nous examinons si le stade du cycle biologique de la proie peut être un facteur qui affecte les réactions d'alimentation des proies à la présence de signaux chimiques de prédateurs en utilisant des pourpres de l'Atlantique (Nucella lapillus (L., 1758)) et leur proies principales, les balanes communes (Semibalanus balanoides (L., 1758)) comme système modèle. Les balanes utilisent leurs pattes modifiées (cirres) pour extraire leur nourriture par filtration de la colonne d'eau. Lors d'une expérience de manipulation en laboratoire, nous avons testé l'hypothèse selon laquelle la présence de pourpres affecte la fréquence de balayage des cirres différemment chez les balanes jeunes et adultes. Les jeunes ont une activité alimentaire semblable, que les pourpres soient présents à proximité ou non, mais les adultes ont une fréquence de balayage des pattes significativement réduite en présence des pourpres. Une tel changement ontogénique dans la réaction des balanes aux signaux de prédation des pourpres peut s'être développé du fait que les pourpres préfèrent les balanes adultes aux jeunes, comme on l'a démontré anté-rieurement. D'un autre côté, les balanes pourraient avoir appris avec l'âge à reconnaître les signaux des prédateurs, comme c'est le cas chez d'autres espèces de proies. Globalement, notre étude indique que pour pleinement comprendre les effets (autres que la consommation de la proie) des prédateurs sur les proies, il est nécessaire...

A death in the family: Sea lamprey (Petromyzon marinus) avoidance of confamilial alarm cues diminishes with phylogenetic distance

“…Alarm cues are expressed by major aquatic taxa from both freshwater and marine environments, including echinoderms (Hagen, Anderson, & Stabell, ; Majer, Trigo, & Duarte, ), mollusks (Daleo et al., ; Dalesman, Rundle, & Cotton, ; Wood, Pennoyer, & Derby, ), crustaceans (Hazlett, ), arachnids (Persons, Walker, Rypstra, & Marshall, ), acarids (Grostal & Dicke, ), insects (Gall & Brodie, ; Llandres, Gonzálvez, & Rodríguez‐Gironés, ), and fishes (Brown, Ferrari, & Chivers, ). Damage‐released alarm cues also mediate learned predator recognition, including the relative level of risk posed by individual predator species (Brown & Chivers, ; Chivers & Smith, ; Gherardi, Mavuti, Pacini, Tricarico, & Harper, ; Wudkevich, Wisenden, Chivers, & Smith, ), changes in the relative threat through ontogeny (Johnston, Molis, & Scrosati, ), and the labeling of risky habitats (Chivers & Smith, ).…”

Predator nonconsumptive effects on prey recruitment weaken with recruit density

“…Predators, however, may also have nonconsumptive effects (NCEs) on prey. Through the detection of waterborne chemical cues released by predators, adult prey may decrease feeding or move away to avoid predation (Trussell et al 2003, Keppel and Scrosati 2004, Molis et al 2011, Johnston et al 2012, Orrock et al 2013. As NCEs from nearby predators can influence many prey organisms simultaneously, such effects may have larger consequences for prey populations than consumptive effects (Preisser et al 2005, Trussell et al 2006, Matassa and Trussell 2011.…”

Water motion modulates predator nonconsumptive limitation of prey recruitment

“…Predators regulate prey populations through direct consumption, but they also have a variety of nonconsumptive effects (NCEs) on prey. For instance, when prey species detect chemical cues from nearby predators, immediate responses often include moving away or decreasing feeding activities to reduce predation risk (Trussell et al 2003, Keppel and Scrosati 2004, Large et al 2011, Molis et al 2011, Johnston et al 2012, Orrock et al 2013. Such chemically mediated NCEs are common in aquatic and terrestrial predator-prey systems (Hermann andThaler 2014, Matassa andTrussell 2015).…”