New preprint about parasite effects on organismal movement

Today we published a preprint of our paper titled Schistocephalus parasite infection alters sticklebacks’ movement ability and thereby shapes social interactions to bioRxiv. Although many fundamental aspects of host-parasite relationships have been unravelled, few studies have systematically investigated how parasites affect organismal movement. In this study we combine behavioural experiments of Schistocephalus solidus infected sticklebacks with individual-based simulations to understand how parasitism affects individual movement ability and how this in turn influences social interaction patterns.

By detailed tracking of the movements of the fish, we found that infected fish swam slower, accelerated slower, turned more slowly, and tended to be more predictable in their movements than did non-infected fish. Importantly, the strength of these effects increased with increasing parasite load (% of body weight), with the behaviour of more heavily infected fish being more impaired.

When grouped, pairs of infected fish moved more slowly, were less cohesive, less aligned, and less coordinated than healthy pairs. Mixed pairs exhibited intermediate behaviours and were primarily led by the non-infected fish. These social patterns emerged naturally in model simulations of self-organised groups composed of individuals with different speeds and turning tendency, consistent with changes in mobility and manoeuvrability due to infection.

Together, our results demonstrate how infection with a complex life cycle parasite affects the movement ability of individuals and how this in turn shapes social interactions, providing important mechanistic insights into the effects of parasites on host movement dynamics. Download our preprint here!


Learning a new skill: LaTeX

The last few weeks I delved into learning \LaTeX, a code language for more aesthetically pleasing article writing, especially in terms of mathematical formulas. As my research has increasingly been focused on the mechanisms underlying collective behaviour, for which I do a lot of mathematical computations, such an advanced yet simple text-editor is very helpful and overcomes the many pains I have with MS word!

(1)   \begin{equation*} v_i(t) = |\mathbf v_i(t)| = \sqrt{u_i^2(t)+w_i^2(t)}. \end{equation*}

(2)   \begin{equation*} \mathbf a_i(t)= \frac{\mathbf v_i(t+\Delta t) - \mathbf v_i(t)}{\Delta t} = \frac{\mathbf r_i(t+\Delta t) - \mathbf 2r_i(t)+\mathbf r_i(t-\Delta t)}{\Delta t^2}, \end{equation*}

(3)   \begin{equation*} \rho(t)=\frac{1}{n}\sqrt{\left( \sum_{i=1}^{n}\sin(\psi_i(t))\right)^2+\left( \sum_{i=1}^{n}\cos(\psi_i(t))\right)^2} \end{equation*}

It was quite a steep learning curve, but I managed to write my first paper with it last week. The great thing is that it is also possible to use \LaTeX in wordpress (which I used to create this website). It is also the standard language for drafting preprint articles, which is increasingly suggested and done in the biological sciences, thus a very relevant skill to learn.