Columbian Sharks

Question
QUESTION: I have three Columbian Sharks in my 135gallon tank one of them the larger one has a mass on each side of it right above its back fin. Taking a guess but i dont know were they came from just popped up over night, is it trying to mate are they the fishes sexual organs?

ANSWER: Lance,

 To start, that tank is way to small to house 3 of them. They need 75 gallons each as a minimum. As far as I know, no one has ever bred them in captivity, so if they do breed, you are once lucky guy. Are these fish in fresh water? If so, they need to be in brackish water. If they aren't, then you need to start adding salt to the water. Without a picture its hard for me to figure out what's going on. How is he swimming, eating, acting? I doubt they are sexual organs on his back, but it could be a sign that he wants to breed. How are the water perimeters? meaning the ammonia, nitrates and nitrites? If you want to kepp them as healthy as possible, you need to move the to a tank no smaller than 225 gallons. You might want even bigger to help them turn around without hitting the tank walls. Are they showing any signs of illness like white spots, or sores? If you can it would help a lot if you can post a picture of the fish in question. That way I can see it and maybe be able to help you out better.

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the thing above the ba   QUESTION: They are all healthy eating habits are great they eat more then i do lol. I feed them sinking pellets and hole krill and algae wafers. They prefer the krill. Well now that i no the tank is to small i most likely am going to put them up for adoption and do plan on turning the tank to salt once i move in October. Attached is a pick of the fish and the weird objects also the fish keeps rubbing on the other fish. I also have more picks but this site only lets me send one if you need more.  

Answer
Lance,

It could be because he is in the mood to breed. I would just continue to watch him very closely. Make sure nothing changes ie: swimming different, not eating, getting aggressive, of anything else. It could me something that happens when they are in tanks. In the pic it doesn't look like he was injured in any way. Like I said, just keep an eye on him and if anything changes let me know.