Figure 7. Microbiota exhibit different responses to diet in captive male and female stickleback.
We obtained gut microbial DNA from lab-reared stickleback fed chironomids (15 females, 13 males) and Daphnia (14 females, 13 males). We obtained a total of 5,226,827 sequence reads from 15 females (red points) and 13 males (blue points) experimentally fed chironomids (circles), and 14 females and 13 males fed Daphnia (triangles). We averaged 54,446 sequence reads per sample (range: 406–299,947; mean of 31,409), identified as 1,460 microbial OTUs. Here we plot individuals’ scores along the first two linear DFA of microbiota composition (unweighted PCoA axes 1–21) that separate groups (combinations of sex and diet). Larger points with s.e. bars indicate group means. Within each sex, lines represent the diet effect (connecting means for Daphnia- to chironomid-fed fish); the angle between these lines emphasizes the sex-dependent diet effects. In particular, the following taxa are more common in Daphnia-fed males and chironomid-fed females: OTUs in the families Hyphomonadaceae (P=0.0000014), Isosphaeraceae (P=0.00006), Haliangiaceae (P=0.00016), Staphylococcaceae (P=0.0015), Pirellulaceae (P=0.0018), Aeromonadaceae (P=0.0035) and Saprospiraceae (P=0.0036), and in the genera Burkholderia (P=0.000010), Veillonella (P=0.0000012), Staphylococcus (P=0.000018), Stenotrophomonas (P=0.00135) and Paracoccus (P=0.0018).