Actually, all those parameters are still being passed along, you are just not attaching them to the uri. Passing parameters to $req->content() is adding the parameters to the content portion of the HTTP packet... The port number makes no difference. Hmmm...
This is how I would do it (in case anybody was wondering):
use strict;
use LWP::UserAgent;
use LWP::Debug qw(+);
use HTTP::Request;
my $ua = LWP::UserAgent->new;
$ua->agent("Wobbygong Shark/ 0.1");
# Create a request
my $req_method = 'GET';
my $url = "http://thebigwobbygongsharkonheat.aquaworld.tv:8081/";
my $res;
my $content_params = 'oneandthesame=;';
my $req = HTTP::Request->new(
$req_method=>$url,
HTTP::Headers->new(
'Content-Type'=>'application/x-www-form-urlencoded')
);
$req->content($content_params);
$ua->request($req);