Comparative assessment of Texas horned lizard (Phrynosoma cornutum) gut microbiome diversity and composition throughout transition from captivity to wild

Abstract

<i>Microbiomes play a key role in the health of animal hosts. To improve</i><br><i>conservation translocation programs like headstarting, it is necessary to</i><br><i>consider how the structure of these programs impact the host-associated</i><br><i>microbiome. Bringing animals into captivity introduces novel diets and</i><br><i>environments; however, the extent to which these factors contribute to the</i><br><i>structure of the host</i><i>’</i><i>s gut microbiome remains poorly understood. Additionally,</i><br><i>it is unclear if periods of captivity leave a lasting signature on the host-associated</i><br><i>gut microbiome, which could impact individual health and </i><i>fi</i><i>tness in the longterm.</i><br><i>In this study, we repeatedly sampled the gut microbiome of a cohort of</i><br><i>headstart Texas horned lizards (</i><i>Phrynosoma cornutum</i><i>) throughout their</i><br><i>transition from captivity to the wild. We also collected samples of extrinsic</i><br><i>microbial communities present in their captive and wild diet and environment.</i><br><i>Finally, we sampled the gut microbiome of wild resident lizards to serve as a</i><br><i>baseline comparison. Using 16S rRNA microbial inventories, we examined</i><br><i>differences in microbial community composition and diversity between prerelease</i><br><i>headstart, post-release headstart, and resident lizards of the wild</i><br><i>population. Additionally, we assessed the contribution of environmental and</i><br><i>dietary microbial communities to the assembly of </i><i>P. cornutum </i><i>gut microbiomes</i><br><i>in captivity and the wild. Our results suggest captive </i><i>P. cornutum </i><i>harbor gut</i><br><i>microbiomes that are distinct from their wild counterparts. However, within twomonths</i><br><i>post-release, the headstart gut microbiome restructures to be</i><br><i>indistinguishable from the wild resident microbiome. Microbiomes associated <i>with the captive diet and environment are distinct in beta diversity, but not alpha</i><br><i>diversity, from those in the wild. Our results provide important insights into hostassociated</i><br><i>microbiome dynamics associated with transition from captivity to the</i><br><i>wild and can be used to inform conservation translocation practices.</i></i>