why?

Question
i have two male guppys, and recently i noticed that one of them only swims at the bottom of the tank now. he won't come to the top unless it is feeding time. then i noticed that he has this weird shape now. he looks like someone bent him and then left him that way. he was straight wen i first bought him a few months ago. it almost looks like he has a huge bubble on one side of him and not the other. please help me i hope i have given enogh info

Answer
Hi Diana:  The guppy may have an internal parasite, an intestinal blockage, or just what we call "bent fish syndrome"  which can be caused from running into something, a fish disease called fish TB, vitamin deficiency or even a poor diet.  I would add some aquarium salt to the water as it may provide some much needed minerals to him.  I would also make sure that your water chemistry is in the proper safe ranges.  I would include brineshrimp in his diet mostly because if it is an intestinal blockage the brine shrimp will help it pass.  Brine shrimp also provide trace elements like iodine to fish.  If he does not get better in a day or two let me know.  Also let me know if he gets any worse.... dave