You could use zsh with its [expression-as-a-glob-qualifier](http://zsh.sourceforge.net/Doc/Release/Expansion.html#Glob-Qualifiers) to select files that only have nine such symbols:

 $ hasnine() { [[ $(tr -dc '>' < "$REPLY" | wc -c) -eq 9 ]]; }
 $ mv *.fna(+hasnine) location/

The first line defines a function whose purpose is to create a true/false filter for files that have nine `>` symbols in them. The `tr` command acts on its input, expected in the `REPLY` variable, deleting anything that is not a `>`, then asks `wc` to count the number of resulting characters, and then compares that output to 9.

The second line executes the `mv` command for matching *.fna files to the (example) `location` directory. Matching *.fna files also have to pass the expression qualifier, which is given as the name of the function we defined.