Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2023
Höfundar / Authors: Guðrún Ósk Sæmundsdóttir, Haseeb Randhawa
Starfsvettvangur / Affiliations: University of Iceland, Faculty of Life and Environmental Sciences
Kynnir / Presenter: Guðrún Ósk Sæmundsdóttir
Fish in lake systems can undergo adaptive radiation when different groups within a species occupy distinct niches. This enables habitat specialisation, giving rise to rapid divergence, both morphological and genetic, sometimes eventually resulting in reproductive isolation and sympatric speciation. The threespine stickleback (Gasterosteus aculeatus) is a good example of this phenomenon, where different ecotypes exhibit morphological variations reflecting their environment. This study explores the potential of parasites as indicators of ecotype differentiation. Fish of three ecotypes of threespine sticklebacks from lake Þingvallavatn were examined for parasites and linear discriminant analysis employed to assign hosts to their respective habitats. The results show a depth-dependent axis in parasitic infection rather than a temperature one, with ectoparasitic monogeneans having the most significant impact, indicating that depth might be a bigger factor than temperature in shaping the parasite communities. These findings suggest that variations in parasite loads can serve as indicators for distinguishing between sticklebacks from different environmental conditions and emphasize the importance of considering the entire parasite community in analyses. The implications of this study extend beyond lake Þingvallavatn and threespine sticklebacks and could be extrapolated to other freshwater or marine systems as well as various fish host species.