How To Make Fig8 & Gsp Grow To Full Size?

[babyduke]

I have 1 fig8 & 2 gsp in my 55g tank which I purchased as juveniles 2 yrs ago. Yet they are very small still especially the fig8's. I went to Shedd Aquarium recently and to my pleasant surprise, there was a tank dedicated for these 2 species. They were huge and I've never seen them this big anywhere. Is it the size of the tank or the diet? FYI I feed mine pretty good and take care of the tank meticulously.

 

[nmonks]

There will be many factors at work. The prime one is swimming space -- bigger tanks with industrial-scale filtration encourage faster growth rates thanks to better water quality. This isn't to say you have poor water quality, but the confines of a home aquarium simply mean that, usually, water quality isn't *quite* as good. It's just a question of scale really: big tanks, big filters.

But there's also variability in the growth rates within species (in fish just as much as in people). The maximum sizes for fish aren't "guaranteed" in any way, so it is perfectly possible to end up with a fish much smaller than you expect. In fact, it is rather common for fish to stay smaller in captivity anyway. (On the other hand, in some cases fishes get bigger in aquaria than in the wild.)

Your figure-8s should get to about 6-7 cm in captivity, and in the wild don't get any larger than 8 cm. GSPs (both species) are around the 15 cm mark in the wild but are often a trifle smaller in home aquaria. It should take about 2 years for your fish to reach maturity, but do bear in mind fish grow throughout their lives, and bigger fish are always the oldest fish in the group (all else being equal). So maybe waiting a little while longer is they key!

Cheers, Neale