Why Isn't He Growing....

[Behold]

I have 2 sailfin pleco's and they were both bought at about 4cm each. one is now at about 15cm and the other is still 4cm.

He seems happy loves hanging out on any leaf free and playing in the current of my outlet.. he eats fine too.

Is it is normal?

Thanks.

 

[xingumike]

Its definitely a gibby as well? is a picture possible?

 

[Colin_T]

it is being dominated by the other one.

 

[xingumike]

and that would stop it growing how?

 

[Colin_T]

stress caused by bullying. It happens all the time in cichlids. A fish dominates the others and grows really big while everyone else stays small.

 

[xingumike]

A gibby that grown 10 cm (thats 4 inches) must have been in the tank approximately 3-4 months i would guess.

the other gibby has been in the tank the same amount of time, is eating and 'seems happy' (indicates not bullied to me) has not grown at all? doesn't sound right at all.

I can't see how a 5 inch gibby can dominate another one so much in a 120 gallon tank

 

[Colin_T]

it could be worms then. The fish will feed but not grow. The worms will be sucking all the blood out of the fish and causing anaemia

 

[Behold]

he is not bullied but is dominated. but they normally keep to themself. they were not always in a 120gallon tank but still kept away from eachother. he eats but is not a pig about it.

i have had them about 5-6 months.

there is no colour loss in the small one at all infact he is vibrant. surly if he had anemia he would loose colour??

 

[Colin_T]

if they have worms they lose condition but stay the same colour. It also depends on how many worms the fish is infested with. A couple of worms will only take a bit of blood and the fish can survive without any problems. A massive worm ifestation can cause fish to lose weight rapidly. The fish's colour doesn't normally change.

Are you doing lots of water changes and gravel cleans? Fish release a hormone into the water to inhibit the growth of other fish aorund them. In a river it gets washed away but in the confines of an aquarium it builds up and prevents everyone but the biggest fish from growing. Regular partial water changes dilute the hormone and encourage good growth rates in all inhabitants.
Make sure any new water going into the tank is free of chlorine and has a similar temp & PH to the tank.

Have lots of ornaments/ hiding places in the tank to break up territories.