Polys Not Growing

[Tobigara]

i've had a senegal for about a year now and a retropinnis for about 4 months. i figured that all polys are fast growers but the retropinnis hasn't grown at all and the senegal hasn't grown in the last 7 months.

i alternate frozen foods between brine shrimp, bloodworms, mysis shrimp and krill with a staple of hikari carnivore pellets. the senny is about 5 inches in 44 gallon with 2 ctenapoma and a syno eupterus. the retro is still about 2.5 inches in a 10 for growing out

did i do something wrong? is it something i can correct and have them grow a bit?

any advice/insights are appreciated

 

[nmonks]

I suspect this makes the argument that in small tanks fish don't grow so quickly.

While this isn't the same thing as the fallacious "stunting damages fish" nonsense that goes around the hobby, it certainly will be more difficult to maintain good water quality in a small aquarium. This is especially so in a tank where you're keeping a predatory fish and so using high protein foods. In other words, nitrate levels will rise faster than if you were keeping just a school of neon tetras. That in turn could suppress growth alongside other potentially deleterious effects on the heath of the fish.

Once the Polypterus retropinnis is moved into a more spacious tank (at least 20 gallons, and ideally 30+ for this species) you should observe its growth rate increase. Fish grow throughout their lives, albeit at different rates, so if a fish is moved into healthier conditions and given the right diet, it should increase in size.

Cheers, Neale

 

[Tobigara]

that sucks!! i only put the retro in the 10 so he wouldn't be out-competed for food in my other tanks while he was so small. i'll move him then. i have a 60 that i can put him in. what about the senny in the 44? it's a good sized tank with only 3 tankmates...none of which are full grown.

 

[beblondie]

I suspect something else isn't quite right in this process,I use ten gallon tanks regularly for growing out poly's and never really had an issue.WHat are your water chems. and lighting period?
Your senegal is most likely farm raised and I am hearing more and more about slow growth in captive bred senegals,Since we don't know how deep the gene pool is they are using I suspect theres genetics at work here.
I have to admit the retropinnins has me a bit stumped but i'll think it over and get back to you-Anne

 

[Tobigara]

pH: 7.3 - 7.5
kh: 3-4
ammonia: 0
Nitrite: 0
Nitrate: never above 20
Lighting from about 5pm to about 11pm with a standard light fixture and bulb

if there is any other info you need that i neglected to mention just let me know

any help is greatly appreciated anne