Implications for investigating the adaptive benefit of cavefish
traits
Our study provides important context for research on the evolution ofA. mexicanus behavior and metabolism as these traits are known to
be influenced by microbiome composition. For example, cavefish have
reduced aggression , which can be recapitulated in flies, mice, and
hamsters through microbiome manipulation . In addition, cavefish are fat
and insulin resistant which is associated with microbiome changes in
fish and mammals . When considering the adaptive benefit of A.
mexicanus traits recorded in the laboratory, it is important to note
that the laboratory environment does not recapitulate either wild
habitat (river or cave) and the fish display considerable plasticity in
some traits . We showed that laboratory raised fish harbor a more
diverse microbiome compared to their field caught counterparts and that
the laboratory microbiome contains more of the taxa in wild surface fish
compared to the wild cavefish. Our results serve as a foundation for
understanding how different microbial taxa impact A. mexicanusphenotypes which will lead to a better understanding of cavefish
evolution.