Smaller tanks Stunt Growth

[akabryanhall]

I was wondering what you guys thought about an observation I've made; that a fish grows into the tank its in. Now I'm not going to go buying large species of fish thinking that it won't grow too large, but..
I have seen on numerous occasions that a fish's size depends on his surroundings
Instance 1, My purple tang has been in my 92G corner since the previous owner bought him, so hes over 4 years old. These fish should grow quite large, up to 10" in some cases. Mine has stopped at 5"
Instance 2, I had a clown and a couple cardinal fish in my 29G biocube, for a couple years they grew and then stopped after a while. When I moved them into my 92G all three grew significantly over the next year.
I have observed other instances as well.
Are these just coincidences or does it depend on the individual fish?

 

[Tabasco1]

From what I understand, living in a space that is not ideal will "stunt" a fishes growth, but is not healthy for them and will likely have a corresponding shorter lifespan. Similar to a person who is not getting enough nutrition. Will it kill them immediately? No, but they won't reach their full physical potential and likely live a shorter life.

Best example is goldfish. This is said all the time that a goldfish will grow to it's surroundings. It is true that if kept in a 1 gallon bowl it will not overgrow the sides, but it will only live a couple years at best and the life span of a goldfish is between 8-12 years, could be longer.

 

[Anthony Calfo]

actually...numerous fishery studies have been done here...big money is at stake.The results are interesting. Freshwater species - generally coming from closed or at least smaller water systems compared to marines respond acutely to hormones given off by other fishes that stunt their growth. A species can stunt its own growth in fact in poor conditions (drying ponds). And conversely, with constant flow through water (fisheries with river feeds) fishes can grow almost unrestricted as long as there is enough food (I saw once fishery experiment where trout grew full size in a tube touching each other(!) with food laden water passing by for them to snap at.

Marines, however, do not waste energy on producing hormones to stunt other fishes (no biological evolution for it since theres no way for a fish to influence the ocean, frankly, versus a pond, lake or trib). For marines, tank size is everything. The longer and taller the tank, the bigger the fishes will get. And yes, they do stunt and even die prematurely (developmental retardation) if kept in tanks too small, such as large species tangs "mysteriously" dying after a few years when they can live well over 30. A better documented example is small reef sharks in public aquaria. They've been shown to need about 70+ ft of tank to execute a single rest-glide-recovery sequence. Few aquaria are that long...so they replace dying sharks every 3, 5 or 7 years as needed. Whatever, to them

 

[butts182]

that's good info...for some reason i thought that saltwater fish would continue to grow in small tanks.

 

[Just Clownin Around]

i have my own thoughts about an improper sized tank that can cause degraded muscle tone and strength which in turn will hinder the fishes growth in the long run

 

[akabryanhall]

actually...numerous fishery studies have been done here...big money is at stake.The results are interesting. Freshwater species - generally coming from closed or at least smaller water systems compared to marines respond acutely to hormones given off by other fishes that stunt their growth. A species can stunt its own growth in fact in poor conditions (drying ponds). And conversely, with constant flow through water (fisheries with river feeds) fishes can grow almost unrestricted as long as there is enough food (I saw once fishery experiment where trout grew full size in a tube touching each other(!) with food laden water passing by for them to snap at.

Marines, however, do not waste energy on producing hormones to stunt other fishes (no biological evolution for it since theres no way for a fish to influence the ocean, frankly, versus a pond, lake or trib). For marines, tank size is everything. The longer and taller the tank, the bigger the fishes will get. And yes, they do stunt and even die prematurely (developmental retardation) if kept in tanks too small, such as large species tangs "mysteriously" dying after a few years when they can live well over 30. A better documented example is small reef sharks in public aquaria. They've been shown to need about 70+ ft of tank to execute a single rest-glide-recovery sequence. Few aquaria are that long...so they replace dying sharks every 3, 5 or 7 years as needed. Whatever, to them

Well I'm glad I wasn't just seeing things! Thanks for the info. Now as far as small sharks, are we talking bamboo cat shark small or bigger species?

 

[Anthony Calfo]

Ah, sorry...by "reef sharks" I literally meant those familiar ones with said common name, such as "black tip reef shark" and "white tip reef shark" as well as Triakis (leopard) or smoothounds that are routinely seen in public aquaria (tragically in the aquarium trade too). These are typically 6-12 ft as adults...and yet "max" out at 2-3 ft in home aquaria after a few years and then "mysteriously" die. Its really not that mysterious if you dissect them afterwards.

The bamboo and epaulette (and some smaller cat sharks) are actually very well suited for captivity. They are some of the only elasmobranchs, in fact, that can honestly live a full and healthy lifespan in typical home sized aquaria. Enjoy...they really are lovely. Temperature and water quality tolerant, grow fully and reproduce, etc.

 

[akabryanhall]

What sort of length of tank would one need for a Bamboo Cat shark?

 

[Anthony Calfo]

the banded and spotted bamboo sharks can be kept in pairs in a tank as small as a 4ft 90 gallon. Larger would be nice, but they aren't terribly active. They will breed in a tank that small. Lovely reef sharks IMO

 

[Captain Nemo]

Wow awesome info guys. I have wondered this since my regal hasn't grown but maybe 1/2 inch in almost a year. This explains why, great write up.

 

[Tabasco1]

Really?? When I looked them up said that their adult size was upwards of 3ft. I would think that a 4ft tank would not be enough.

 

[Anthony Calfo]

The bamboo sharks are a unique skew to typical stocking (by length) recommendations. They are whip thin and have extremely long tails that they use something like a kangaroos tail for leverage and movement - out of water! - while hopping from tide pool to tide pool to hunt prey. But in terms of actual body length and bioload, they are very modest. Again, a single pair (alone) as breeders in a 90 gall has been shown to work even for breeding. I'd hope of course that you'd do larger.

 

[Wy Renegade]

actually...numerous fishery studies have been done here...big money is at stake.The results are interesting. Freshwater species - generally coming from closed or at least smaller water systems compared to marines respond acutely to hormones given off by other fishes that stunt their growth. A species can stunt its own growth in fact in poor conditions (drying ponds). And conversely, with constant flow through water (fisheries with river feeds) fishes can grow almost unrestricted as long as there is enough food (I saw once fishery experiment where trout grew full size in a tube touching each other(!) with food laden water passing by for them to snap at.

Marines, however, do not waste energy on producing hormones to stunt other fishes (no biological evolution for it since theres no way for a fish to influence the ocean, frankly, versus a pond, lake or trib). For marines, tank size is everything. The longer and taller the tank, the bigger the fishes will get. And yes, they do stunt and even die prematurely (developmental retardation) if kept in tanks too small, such as large species tangs "mysteriously" dying after a few years when they can live well over 30. A better documented example is small reef sharks in public aquaria. They've been shown to need about 70+ ft of tank to execute a single rest-glide-recovery sequence. Few aquaria are that long...so they replace dying sharks every 3, 5 or 7 years as needed. Whatever, to them

Interesting read - I'd always heard something along that line in regards to freshwater, but somehow it never seemed to carry over to saltwater.

 

[_Alex_]

my understanding on the tangs suddenly dyeing off after several years is there outer bodies growth is stunted but there internals are not so much and the basically outgrow them selves from the inside out. atleast thats how it was explained to me at one time...

 

[akabryanhall]

Isn't it great having Anthony around!! A wealth of information!!

 

[Anthony Calfo]

Correct Harry...this is the problem with all fishes kept in undersized aquaria. A simple dissection will reveal it clearly in most cases. The tang police fail to use adequate bullets when they (ungracefully) chide the people that bristle (ungracefully) at being chided. LOL But it is what it is: physical and clinical retardation...and no amount of drama or blustering can deny the facts that are plain to see on a lab table (the dissection of fishes denied adequate captive husbandry).