use 5.16.2;
use warnings;

my $annotationfile = "file.tsv";
open my $fh, "<", $annotationfile or die "$annotationfile: $!\n";

# First read the header
my @hdr = split m/\t/ => scalar <$fh>;

my %GOHash;

# Now read every line
while (<$fh>) {
    chomp;

    # read as a hash
    my %hash;
    @hash{@hdr} = split m/\t/ => $_, 11;

    $GOHash{$hash{Symbol}}{$hash{"Taxon Name"}} = $hash{ID};
    }