This thesis investigated differences in foraging behaviour, personality and parasitic infection, using behaviour experiments, traditional parasitology and molecular ecology. Five fish species, and a directly-transmitted ectoparasite, were used as model organisms. Evidence for a conservative foraging strategy was found in the four tropical fish species (Poecilia reticulata, P. sphenops, Xiphophorus maculates, X. hellerii) and in a temperate species (Gasterosteus aculeatus). In the latter, this behaviour was unaffected by social context, with no significant differences between isolated fish and shoals. Also, guppies showed a reduced acceptance of novel, conspicuously-coloured prey. Furthermore, using molecular scatology techniques, both prey and host species-specific DNA were detected in fish faecal samples so this methodology can be used in the future to examine diet in the wild. When considering the personality trait, boldness, guppies from two wild populations differed significantly in their relative boldness, but individuals within a single population were similar in their relative boldness. Boldness of fish was affected by mating, with virgin and pregnant females being bolder than their mated counterparts. Also, boldness impacted on shoaling behaviour, shy fish formed larger and tighter shoals than bold conspecifics. This had consequences for parasite transmission, with shy fish having higher parasite loads and a greater change in parasite load across an infection period than their bold counterparts. Furthermore, host contact was the main factor influencing transmission of a directly-transmitted ectoparasite within a group-living host species. Significantly more parasites were transmitted between hosts when hosts had more frequent and more prolonged contact with each other. Clearly, monitoring individual differences in various aspects of an animal's behaviour can answer many questions of ecological relevance, as well as discovering the evolutionary origins of such individual behavioural traits.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:585042 |
| Date | January 2010 |
| Creators | Richards, Elizabeth Loys |
| Publisher | Cardiff University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://orca.cf.ac.uk/55475/ |
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