while (<MYFILE>) #this is my opened file
{
       {        
            	
	    next if /^\s*File/;  	#remove line starting with filename

	    ($id, $seq) = split;       	
	    push @{$species{$id}}, (split //, $seq);   	 
       

	 }        

##</code><code>##


while (($key, $sequence)=each %species)
	{
	print $key,$sequence; 
	print "\n";
	}