Acknowledgements
This research was supported by NSF CAREER Award 1938571 and NIH/NIDCR R01 DE027052 grants to CHM. We thank L. Smith in the Evolutionary Genetics Lab at the University of California, Berkeley, for generous logistical assistance in preparing microbiome samples; S. McDevitt, C. Miller, and D. Pappas at the Vincent J. Coates Genomics Sequencing Laboratory California Institute for Quantitative Biosciences (QB3)  for processing our microbiome samples for 16S amplicon sequencing; R. Berlemont at California State University, Long Beach and C. Weihe from the Microbiome Consortium at the University of California, Irvine for suggestions on microbiome extraction protocols and bioinformatic workflow. We thank the Zoological Society of London for providing C. tessellatus eggs and the governments of the Bahamas and United States for permission to collect and export Cyprinodonsamples.