Expert: Christy - 10/4/2008

Question
Hi there, A question that has been bugging me for a while is that if fish when bought at a young age grow to the size of there tank, I have had a fare few angle fish from a variety of shops that were small when purchased but only grew a few inches but stayed at a resonable size to the tank, I have recently become interested in Discus and wondered if this would be the case for them aswell, WB. Ben

Answer
Hi Ben
What you're referring to is called stunting.  It's not a good thing to do to a fish.  The way I understand it, there's a hormone in fish, and if the tank is too crowded or too small, this hormone releases and makes the fish stop growing.  But, it's insides continue to grow, so you end up with a distorted, round looking fish that will be unhealthy and not live to it's full potential life span.  I had some really good photos of a goldfish and oscar that were severly stunted, but unfortunately they haven't been working on the particular site.  When you get into cichlids like angels etc., they do actually have long life spans.  I have some that are going on 9+ years, with about 10-15 years the average life span for a lot of cichlids.  Your community types of fish usually live about 1-5 years depending on the types, catfish 7+, goldfish 20+.  That's just general guidelines, and there's lots of factors involved as well, but if you have angel fish that only survive 2 years, that's not even close to their life span, and I would say stunting would have a significant impact on that.

I usually go a bit conservative when recommending types and amount of fish and tank sizes, and a lot of that is due to the experience level of the person.  But, for example, I would never recommend anyone keeping an oscar in anything smaller then a 55 gallon tank-which is really a bare minimum.  But for a new person, I might recommend a 75 gallon for an oscar.  Just depends.  As for discus, I wouldn't recommend trying to stunt them.  They're a sensitive fish anyway, and I would follow their care instructions to a T.  Just my opinion though.

Hope that helps!

Christy