Vicki Macnab

The impact of anthropogenic and natural stressors on sticklebacks

I am interested in the impact of anthropogenic stressors on host parasite interactions. At the moment, I study this in aquatic environments which are particularly threatened as they can act as a sink for pollutants.

Currently, I use the three spined stickleback as my model fish, and alongside this use the tapeworm, Schistocephalus solidus which sticklebacks can become naturally infected with in the wild. The tapeworm establishes in the body cavity of the stickleback, and can often account for up to 50% of the host’s mass. The parasite has a significant impact on the reproduction and behaviour of the fish.

One of the main anthropogenic stressors I am interested in is endocrine disrupting chemicals (EDCs), which are being shown to be present in our water courses.  Presently, I am investigating the impact of oestrogen exposure on infection susceptibility and disease progression in the stickleback.

Another area that I am interested in is the potential effects of climate change on host parasite interactions. Again using the stickleback, I am investigating the effect of temperature change on disease progression.

Finally, I am interested in the different infection phenotypes that Schistocephalus and other parasites can cause, and the mechanisms that they use to do so. Particularly, I am interested in the effects of parasites on the reproductive capacity of their host. Parasites often interfere with the classical host trade-off between growth, maintenance and reproduction. By directing energy away from reproduction, the parasite utilises energy that is unlikely to affect the growth and survival of the host, and thus transmission to other hosts. Currently, I am investigating the mechanism behind reduced reproductive capacity in the stickleback-Schistocephalus system, concentrating on the impact of parasitism on the endocrine system and sex steroid production.

The PhD is funded by BBSRC with CASE funding from Cefas Weymouth

BBSRC

Publication list

Macnab V & Barber I (2011) Some (worms) like it hot: fish parasites grow faster in warmer water, and alter host thermal preferencesGlobal Change Biology  DOI: 10.1111/j.1365-2486.2011.02595.x

Macnab V, Scott A, Katsiadaki I & Barber I (2011) Variation in the reproductive potential of Schistocephalus infected male sticklebacks is associated with 11-ketotestosterone titre. Hormones and Behaviour. 60, 371-379.

Macnab V, Katsiadaki I & Barber I (2009) Reproductive potential of Schistocephalus solidus infected male three-spined stickleback Gasterosteus aculeatus from two UK populations. Journal of Fish Biology 75, 2095-2107.

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