Interaction between host phenotype and microbiome composition inA. mexicanus
Some studies have shown that age and sex can impact fish microbiome
composition . Although not significantly different, the field-collected
surface fish were larger on average compared to Pachón cavefish and were
all sexually differentiated suggesting they may be older (Figure
S1 ). Due to limited availability of samples, we were not able to test
how these variables may impact microbiome composition. However, in the
laboratory we collected fish that were the same age (6-months-old). The
lab-raised morphotypes were not significantly different in weight at the
time of collection, although Pachón and Tinaja cavefish weighed more
than surface fish and Molino cavefish on average (Figure S1 ).
Interestingly, most Tinaja and Pachón cavefish had undefined sex
compared to surface fish and Molino cavefish (Figure S1 ). The
impact of growth rate and delayed sexual maturation on microbiome
composition can be explored in future studies using A. mexicanus .