Predators, parasites, and the social behaviour of the guppy Poecilia reticulata

Stephenson, Jessica 2015. Predators, parasites, and the social behaviour of the guppy Poecilia reticulata. PhD Thesis, Cardiff University. Item availability restricted.

Preview	PDF - Accepted Post-Print Version Download (1MB) | Preview
	PDF - Supplemental Material Restricted to Repository staff only Download (476kB)

Abstract

Predators can have both direct and indirect effects on how their prey interact with parasites. This thesis explores these effects using observational and experimental approaches. A behavioural experiment suggested that the direct effects of predators are size- and sex-biased, with small and male guppies, Poecilia reticulata Peters 1859, more prone to Gyrodactylus turnbulli Harris 1986 parasite-induced vulnerability to predation (Chapter 2). Trait-mediated indirect effects of predators also appear important to this host-parasite interaction, as revealed by surveys of natural Trinidadian populations under different predation regimes. First, predator-driven life history evolution predicts an apparent population divergence in parasite tolerance (Chapter 3). Similar divergence in a second trait, social behaviour, may drive sex- and age-biased parasitism: the guppies most liable to shoal have the highest infection probability (Chapter 4). Social behaviour is thus an important driver of parasite transmission, but how parasites affect social interactions remains poorly understood. The second part of this thesis investigates how guppies may use sensory information to mitigate this cost of sociality. Many fishes rely on chemical and visual information and the interaction between sensory modalities to behave appropriately; for example, chemical cues change how guppies respond to visual cues (Chapter 5). In a social context, guppies use both chemical and visual cues to detect infection in conspecifics, but only avoid those in the later stages of infection (Chapter 6). Infection avoidance behaviour is not innate, but likely results from juvenile guppies imprinting on cues of conspecifics, and associating with these cues in adulthood (Chapter 7). This imprinting-mediated avoidance appears to be adaptive: a transmission experiment showed that the onset of avoidance behaviour coincides with the stage of infection at which conspecifics are most infectious (Chapter 8). The sensory ecology of the host and the community in which it lives therefore have important implications for disease dynamics.

Item Type:	Thesis (PhD)
Date Type:	Completion
Status:	Unpublished
Schools:	Biosciences
Subjects:	Q Science > QH Natural history > QH301 Biology Q Science > QL Zoology R Medicine > RB Pathology S Agriculture > SH Aquaculture. Fisheries. Angling
Uncontrolled Keywords:	Disease transmission, Trait-mediated indirect effects, Parasite-induced vulnerability to predation, Sensory ecology, Chemical ecology, Infection avoidance behaviour, Poecilia reticulata, Gyrodactylus turnbulli, Maladaptive imprinting, Social behaviour
Funders:	Fisheries Society of the British Isles (FSBI)
Date of First Compliant Deposit:	30 March 2016
Last Modified:	21 Feb 2022 16:21
URI:	https://orca.cardiff.ac.uk/id/eprint/73819

Actions (repository staff only)

Edit Item