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Full-Text Articles in Ecology and Evolutionary Biology
Effects Of The Brain Nonapeptides Arginine-Vasotocin And Isotocin On Shoaling Behaviour In The Guppy (Poecilia Reticulata), Babak Ataei Mehr
Effects Of The Brain Nonapeptides Arginine-Vasotocin And Isotocin On Shoaling Behaviour In The Guppy (Poecilia Reticulata), Babak Ataei Mehr
Electronic Thesis and Dissertation Repository
Brain nonapeptides have been suggested to regulate social behaviours. However, the contribution of Arginine-Vasotocin (AVT) and Isotocin (IT) to social behaviour in fishes is not well-characterized. Using the guppy (Poecilia reticulata), I first measured association preference for conspecifics in individuals injected with either AVT, an AVT-antagonist, or saline. The time spent associating with conspecifics did not differ significantly among the injection treatments. However, individuals injected with AVT performed more movement among areas of the tank than individuals injected with either the AVT-antagonist or saline, consistent with an effect of AVT on anxiety-related behaviours (i.e. hyperactivity). Second, I measured …
A Theoretical Perspective On Parasite-Host Coevolution With Alternative Modes Of Infection, George N. Shillcock
A Theoretical Perspective On Parasite-Host Coevolution With Alternative Modes Of Infection, George N. Shillcock
Electronic Thesis and Dissertation Repository
We investigate how natural selection shapes the coevolution of parasitism. We discuss the antagonism fuelled by parasites’ necessity to transmit to novel hosts, and host’s desire to minimise virulence. In support, we build a mathematical model which considers the epidemiology and life-history trade-offs faced by an obligate microparasite and its host. Our model allows parasites to be transmitted to new hosts via direct contact (horizontally) or from parent to offspring during birth (vertically). We test the hypothesis that vertical transmission causes virulence to diminish in the long run, and contrary to widely accepted views, find that vertical transmission need not …