use strict;
use warnings;
use Bio::SeqIO;

my $file = "FastA.txt";
my $seq_obj = Bio::SeqIO->new(-file =>"<$file",-format=>'fasta',);

my %seqPair;
my %seq_NoPair;
while(my $seq = $seq_obj->next_seq){  #iterate through records
        if($seq->desc =~ /.*?pair.*?/i){
                $seqPair{$seq->id}=$seq->seq;
                }else{
                        $seq_NoPair{$seq->id}=$seq->seq;
                        }
        }
        
#use Data::Dump qw(pp);
#print pp \%seqPair;
#print pp \%seq_NoPair;