A "fishy" bump within the dark?+Death for fishys( NOT ON PURPOSES!)?

I have a tank with goldfish, as copious may know from my other questions but anyway, I got alien goldfish from my teacher, i wanted to make one thankful family so i got 1 tiny one and another large white womanly for my male (one happy family!Mommy, Daddy and newborn! ^.^) and it seems they are hitting them selves against the tank wall does anyone think they know what it is? ones roughly speaking 1 Inches and a Cm( the baby) another 2 inches ( the mommy) and the last 2 and a half inches( the daddy). Can you help?

Ok and an added. i have now a female and a mannish, they are chasing each other around the tank and pretty fast at that ( the little one stays out of the way) and i was wondering do ether Male or Female Goldfish die after mating and spawning and laying eggs?
you need similar to a 30 gal + tank for them.they need room to circle
Dwarf comets...you mean baby comets. They will obtain 1 foot long.
Pleaz get them a bigger tank, they will not mate until they are at least the size of the container they are in now.
They are in to small of a container and that is why everything you are explaining is happening!
Answers:    What size reservoir? 3 goldfish are going to need to be in a fairly roomy tank, this could be why, could also be the water its in, what are the parameter like? Ammonia? Nitrite? Nitrate?. And no they dont die after they spawn
They are hitting themselves against the tank walls because the reservoir is way way WAY too small for 3 goldfish! 2.5 gallons is too small for even 1 goldfish!! The ONLY fish that can live happily and be natural in a 2.5 gallon tank is a betta. The reason that your fish are "dwarfed" is somewhat because they are young, but also because they don't have any room to grow because (again) the tank is to small and contained by a tank that size with fish that size there can't possibly be adequate room for them.

Goldfish (especially comets) need at least 20 gallons for the first fish and at least 10 gallons for respectively additional fish. Your tank should be 45 gallons or larger for 3. When fish are not housed in appropriate sized tank, their bodies stop growing but their organs do not, causing them a painful and premature death. That's what dwarfing really is. When full grown, comets are nearly 1 foot long, sometimes larger.

And to answer your second question, neither one dies after spawning and lay eggs.
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