Bug in the tank

Question
We have a 29 gallon tank for 4 months.  We have a molly, 5 patties, 4 guppies, 2 catfish, one baby molly and 2 baby patties.  We have live plants and acquired many snails from one of the plants.  My husband has been feeding the fish every other weekend a treat of frozen brine shrimp.  This morning I found 2 critters in the pipes for the underground filters and was wondering if they could be brine shrimp or what other bugs would grow in the aquarium?  They are about an inch long many legs and clear.  Thanks!

Answer
Here's a link with a picture of a Brine Shrimp.
http://www.livefoodcultures.com/babybrineshrimp.html
Half way down the page is a great pic of brine shrimp.
I think it is safe to assume it is a brine shrimp.  There are lots of parasites and bugs that can be found in an aquarium, but most are tiny and are rarely noticed.  Just as a suggestion, try feeding frozen blood worms instead.  They are generally cheaper and will be a better size for your fish.  If you want to stick with brine shrimp, get ones marked "Baby Brine Shrimp".