title: Size-mediated response to public cues of predation risk in a tropical stream fish.
abstract: In order to investigate any size-dependent differences between behavioural patterns, wild-caught Hart's rivulus Rivulus hartii of varying sizes were exposed to chemical alarm cues extracted from the skin of conspecifics or heterospecific Poecilia reticulata, or a tank water control, in a series of laboratory trials. In response to conspecific alarm cues, R. hartii subjects of the range of body sizes tested exhibited consistent, size-independent antipredator behaviours that were characterized by decreased locomotory activity and foraging levels and increased refuging behaviour. Conversely, focal R. hartii demonstrated significant size-dependent trends in response to heterospecific alarm cues, with smaller individuals exhibiting antipredator responses and larger individuals shifting their behaviour to increased levels of activity consistent with a foraging, or predatory, response. These results show that the behavioural responses of individual R. hartii to publicly available chemical alarm cues from heterospecifics are mediated by the size of the receiver.
authors.affiliation: Department of Biology, Concordia University, 7141 Sherbrooke Street West, Montreal, QC H4B 1R6, Canada. chris.k.elvidge@gmail.com
authors.forename: C K
authors.initials: CK
authors.lastname: Elvidge
authors.forename: I W
authors.initials: IW
authors.lastname: Ramnarine
authors.forename: J-G J
authors.initials: JG
authors.lastname: Godin
authors.forename: G E
authors.initials: GE
authors.lastname: Brown
mesh_terms: D000819:Animal Communication; D000818:Animals; D049628:Body Size / Q000502:physiology*; D003463:Cues; D003532:Cyprinodontiformes / Q000033:anatomy & histology* / Q000502:physiology*; D004924:Escape Reaction / Q000502:physiology*; D005260:Female; D008297:Male; D045483:Rivers; D014329:Tropical Climate