Fish growth + Limiting factors Qs

[AaronM]

What limits fish growth, outside of poor health and genetics?

Water pressure? Swimming area? Constant close prox. to other fish? All?

My bro had a sailfin in a 55g tank. Not ideal i know, but it only grew to about 4". I've seen massive sailfins in bigger tanks and their max size is over a foot i think.

Do fish completely stop growing when adult? E.g if you moved my bros sailfin into a bigger tank, would it have grown despite being adult?

[sslak]

Originally Posted by AaronM

My bro had a sailfin in a 55g tank. Not ideal i know, but it only grew to about 4". I've seen massive sailfins in bigger tanks and their max size is over a foot i think.

Do fish completely stop growing when adult?

Fish are one of the few animals on this planet that never stop growing.

What do you mean "it only grew to 4"? How long did it live?

They have a lifespan of 10 years or more...that's why you see such large fish.

[produceb]

I know most will say different, but it seems to me tank size will limit or slow growth to a extent. I had a queen angel I caught as a juvenile it was in a 125 gallon tank I had it for over 3 years it changed to adult coloring. It never got over 4 inches at most. the tank it was in was built in the wall and you got to the back thru a bathroom. It would get so excited when someone opened the bathroom door that it would almost come out of the tank, one day it did. It sure seemed that fish grew like crazy until it hit about 4 inches. In the wild they grow 10 times the size of the one I had, not 40 inches long but in over all weight and size.

[AaronM]

Man...if you wanna know the truth i just killed that sailfin yesterday. I feel real bad. I had been going so well with my bros tank. I pulled a few rocks and put them in tub, then after a week put them back in with re-arrange. I tested tub for ammonia and nitite a few days after pulling rocks...and seemed fine. Clearly not so when i put the rock back in. Anyway..i understand what happened. I'm cut, but my Q's are still the same... ...haven't told my bro yet, hes on gap yr overseas...Ironically i was mostly re-arranging for the sailfin.

'Big dog' lived for 4 years in my bros 55g and never grew larger than 4". So i guess my question isn't about lifespan *hangs head, grabs beer*, its about what limit fish size? I know if i hadn't killed the beut fish he would have stayed that size...so i don't belive its age that limits size.

So if they don't stop growing, which i suspected, if you moved an adult fish to a bigger tank, would it grow out?...Another question, now i killed the biggest fish in my tank *hnags head*, will the other fish grow bigger?

Yeah produceb seems same to me. But specifically what? pressure, swim area, crowding?
Funny stuff btw re. excitement level

[Uncle Salty 05]

sslak is correct.
The only limiting factor in fish growth is death. As long as they are alive they are growing regardless of what size tank they are in.
That is why groupers should not be sold for this hobby, they will outgrow all but the biggest of tanks. (thousands of gallons)
Same goes for Oscars in FW, unless you tank is 180 or bigger Oscars are not the fish for you.

[anbosu]

Poor water quality and stress due to a lack of space also contribute to a lack of growth.

There are types of groupers that stay small enough for the hobby, but I agree most are inappropriate.

[Uncle Salty 05]

Originally Posted by anbosu

Poor water quality and stress due to a lack of space also contribute to a lack of growth.

There are types of groupers that stay small enough for the hobby, but I agree most are inappropriate.

Poor water quality and stress due to lack of space also contribute to death.

Which groupers stay small enough?

[anbosu]

Miniatus and six line soapfish, for two.

[Uncle Salty 05]

Originally Posted by anbosu

Miniatus and six line soapfish, for two.

Miniatus Grouper - max size 16.1 inches
http://www.freshmarine.com/miniatus-grouper.html

Six Line Soapfish - max size 12 inches (I had one of these years ago and in six months I had to take it back)
http://www.fishchannel.com/fish-maga...formation.aspx

[anbosu]

Originally Posted by Uncle Salty 05

Miniatus Grouper - max size 16.1 inches
http://www.freshmarine.com/miniatus-grouper.html

Six Line Soapfish - max size 12 inches (I had one of these years ago and in six months I had to take it back)
http://www.fishchannel.com/fish-maga...formation.aspx

Both are appropriate for a reasonably large, aggressive style tank. These aren't like tangs where they need a lot of swimming space. They need good water quality and plenty of food.

FWIW I have never seen a miniatus over a foot in captivity.

The soapfish I had grew well, but was not an aggressive fish. I would get one again if I had the chance.

According to fishbase max size for a six line is 30 cm. Still not a small fish, but plenty small for an aquarium.

http://www.fishbase.org/Summary/spec...s&lang=English

[anbosu]

Why did you have to take the six line back? Did you have it in a tank with small fish?

[LobsterOfJustice]

It is my experience that something, wether it be feeding, tank size, etc, absolutely does limit fish size. I had a number of "large" fish (rabbit, butterfly, angel, tang) in a 4' tank (75, then a 90) for several years and they all maxed out about 4.5". However, I know someone with a naso in a 4' 150 and that naso got about 7" in about 18 months, but he was going through a few mysis flat packs a month.

[LobsterOfJustice]

Also, I was blown away by the size of some fish I saw at SeaWorld in San Diego. Naso genus tangs 30", gold spot rabbits 24" easy, and majestic angels and purple tangs the size of car hubcaps. This tank was probably at least 100,000 gal if not several.

[Uncle Salty 05]

Originally Posted by anbosu

Why did you have to take the six line back? Did you have it in a tank with small fish?

It was such a hog I could not get food to the other fish in the tank. It was not agressive except at feeding time. It was only 3-4 inches long and it grabbed my finger up to the second knuckle. I figured while I had him where I wanted him that would be a good time to return him.

[Uncle Salty 05]

Originally Posted by anbosu

Both are appropriate for a reasonably large, aggressive style tank. These aren't like tangs where they need a lot of swimming space. They need good water quality and plenty of food.

FWIW I have never seen a miniatus over a foot in captivity.

The soapfish I had grew well, but was not an aggressive fish. I would get one again if I had the chance.

According to fishbase max size for a six line is 30 cm. Still not a small fish, but plenty small for an aquarium.

http://www.fishbase.org/Summary/spec...s&lang=English

I stand by my ascertion that groupers are inappropriate for home aquaria.
Especially reef tanks, extra large FOWLRs maybe.

[anbosu]

Originally Posted by Uncle Salty 05

It was such a hog I could not get food to the other fish in the tank. It was not agressive except at feeding time. It was only 3-4 inches long and it grabbed my finger up to the second knuckle. I figured while I had him where I wanted him that would be a good time to return him.

I had a porc like that once. I had to net it so I could feed the other fish in the tank.

[anbosu]

Originally Posted by Uncle Salty 05

I stand by my ascertion that groupers are inappropriate for home aquaria.
Especially reef tanks, extra large FOWLRs maybe.

Agree to disagree then.

Generally keeping a large predatory fish in a reef isn't going to work just because of the amount they eat and the waste they produce. Keeping a relatively sedentary 10" max fish in a 120+ gallon FOWLR is totally reasonable, in my opinion.

[jacksonpt]

From my experience, feeding has a BIG impact on growth. I'm not going to say it limits growth, but it does/can slow it down significantly.

[AaronM]

But there must be more to it than the fish grows until it dies. My bros sailfin stayed the same size for years, so something about tank size i think limits fish growth. Btw when i say limit growth, i agree a fish might still be growing, but at a much much reduced rate, e.g 1mm a year.

I never seem to see for e.g. dinner plate size yellow tangs in a 75g tank. If ALL fish just grow and grow to their max in any tank, then there'd be thousands of horry storries about e.g. yellow, sailfin tangs growing into behemoths in small tanks within a few yrs. Anyone experience this?

The sailfin was well fed. He surely had enough nutrition to grow.

If its water pressure or swimming area, then moving a fish that has growth potential limited by the tank its in into a bigger tank will cause a growth spurt. Anyone experience this?

If its more to do with crowding, then removing a few fish from a tank will cause a growth spurt in the remaining fish. Anyone experience this?

Don't have enough experience yet to make up my mind whats gowing on with this.

[AaronM]

Lobsterofjustice: Yeah thats the kind of thing i'm talking about. I think its something to do with tank size.

[AaronM]

More opinions on how tank size affects fish growth? Esp. what happens re. fish growth when a fish is moved to a larger tank, and growth of remaining fish when a fish or two are removed.

The focus of my confusion is tangs btw...seems the best example. Never see hubcap size fish in 75 or 90s... Maybe their lifespan is shortened in these tanks.

Old fish with big max size in regular sized tanks anyone?

Cheerz