my ($c, $species) = (0, shift());

while(<>) {
    chomp;
    next unless length;
    my ($seq, $scount) = split /\s+/;
    next if $scount < 2 || length $seq < 15 || length $seq > 30;
    print ">$species" . $c++ . "_count=$scount\n$seq\n";
}