Data for: Skin bacterial microbiome diversity predicts lower activity levels in female, but not male, guppies, Poecilia reticulata

While the link between the gut microbiome and host behaviour is well established, how the microbiomes of other organs correlate with behaviour remains unclear. Additionally, behaviour–microbiome correlations are likely sex-specific because of sex differences in behaviour and physiology, but this is rarely tested. Here, we tested whether the skin microbiome of the Trinidadian guppy, Poecilia reticulata , predicts fish activity level and shoaling tendency in a sex-specific manner. High-throughput sequencing revealed that the bacterial community richness on the skin (Faith's phylogenetic diversity) was correlated with both behaviours differently between males and females. Females with richer skin-associated bacterial communities spent less time actively swimming. Activity level was significantly correlated with community membership (unweighted UniFrac), with the relative abundances of 16 bacterial taxa significantly negatively correlated with activity level. We found no association between..., These methods are modified from the manuscript:
a)  Fish origin and maintenance
We used laboratory-bred descendants of guppies collected from the Caura River, Trinidad. Guppies were housed at densities of 1–2 fish per litre in 4.5-litre tanks in a recirculating system at 24 ± 1°C, on a 12 L:12 D lighting schedule and fed daily on flake and Artemia. All conditions were kept identical for the experiment duration, conducted in five experimental batches between August and November 2017.
b) Behavioural experiment and microbiome sampling
To assay behaviours, we used a central glass aquarium ('test aquarium'), flanked on both short sides by smaller aquaria ('stimulus aquaria'), all with 5cm water depth. The stimulus aquaria were lit from above by 32cm LED strip lights (350lm, 5W, 4000k, MeRox® Technics). The test aquarium had a black Perspex lid, to which was fastened a GoPro camera (Hero4 Black Edition; GoPro Inc. San Mateo, CA). We placed a test fish (of either sex: n=18 females; 19 males) i..., We have included .csv files containing the data, and a .pdf README file including the R code and output we used to analyse the data, plus more details on the variables in the datasheets.