#husbandy

Hey husbandy

There has been a long held myth in the pet industry that fish will only grow to the size of their tank, and this belief seems to be most commonly held with koi and goldfish. The short answer is that, one goldfish in a ten gallon tank may physically stay smaller than a goldfish that has all of its requirements met, but it will be painfully stunted and cannot live a full life. 

Lets continue using the goldfish example, because koi are not suited for a home aquarium.

A common goldfish (usually called comets, feeder fish, etc) can easily grow to 12-18 inches, and they produce a great deal of waste. These fish are naturally curious and social and prefer to be in tanks with several decorations and other goldfish to keep them company. They can also live for 30-40 years if kept properly. 

A stunted goldfish on the other hand, is diminutive in size, and often only exists for a few years before succumbing to the conditions of its tank. 

For a fish to be ‘stunted’, essentially means that its internal organs have continued to grow while the fishes body hasn’t. Stunted fish usually have curved spines, dis-proportioned eyes and heads, and they may have dis-proportioned bellies as well. stunting can happen for a few reasons but the most common causes are:

poor water quality - The ammonia from the fishes waste has built up to the point that it is poisoning the tank. This happens when there isn’t sufficient filtration, or the fish owner has neglected to do scheduled water changes. Having a messy fish like a goldfish in a small tank makes it incredibly easy for waste to build up to a damaging or lethal point.

GABA- GABA is gamma aminobutyric acid, a hormone that goldfish (and some other fish) naturally produce that has stunting effects. If water changes are not done frequently then growth inhibiting hormones are allowed to build up in the water and may impact the fishes well-being. 

Poor nutrition- There are tons of commercially available fish foods, and constant debate over which ones are better or worse than the others. Many new fish keepers make the mistake of feeding their goldfish food that is designed for tropical fish. Goldfish naturally require food that is high is carbohydrates and relatively low in protein. Tropical fish food is designed the other way around and has a high protein content and a low carbohydrate content. This results in malnutrition for the goldfish, and the additional protein will stimulate its growth and weight gain, which only makes things harder on the fish if it is being kept in too small of a tank. 

To sum up, stunting a fish requires the fish owner to completely disregard the needs of their pet, and forces them to live in conditions which can cause irreparable damage and suffering.

I hope this answered your question, and thank you for the ask! ^_^