# Discussion of the day: Does tank size affect life expectancy of fish?



## Piscesgirl (Feb 25, 2004)

This has always plagued me. I want the best for my fish, and thus have a terrible conundrum of what to do with my clown loaches in the future. Well, interestingly enough yesterday I received three killifish that are the same species as my current four Killifish (I wanted more females but received a male as well). These new killies are about a fourth the size of my current ones, including the fully colored up male! They are teeny tiny. My four current Killies are kept in a 20 long all to themselves, and I know that most Killifish keepers keep their killies in small tanks. 

So....long story short....I assume the very tiny size of my new killies is attributable to being raised in a small container/tank. Does small tanks contribute to a lessened life span or just simply a smaller size? I'm a small individual but that doesn't mean necessarily that my life span will be less than say a 6' person (I hope!!!). Although genetics are the main reason I'm small, I can say diet had a very large impact on my life as a youngster, maybe even 'stunting' me a bit? Who knows? I'm shorter than my parents anyway....

OK, so, does it matter? Will my clown loaches have a short lifespan in a 55 gallon tank? Will my killies have a longer lifespan in a larger tank -- all things being equal?    

What do you think?


----------



## milalic (Aug 26, 2005)

Interesting question...I myself have kept Bolivian Rams that came together.Kept them in different size tanks raging from 10G to 55G and have not notice any difference in size. 

Regarding the example with the killies, I have had mine for a few months now and they have not grown at all. If they have it is not noticeable. they are in a 55G. 


Currently I have three goldfish in a 20G H tank. They have not grown at all and have more than six months in tha tank. I have measure one of them. I did put them in this tank thinking that in six months they would outgrow the tank. It happened to a friend of mine that in a span of 6 months his two goldfish grew 6 inches in his 10G tank.


Based on the experience I have I would think it is a little of both, genetics and tank size. Tank size might be able to slow the growth of a fish to the point where it is barely noticeable. Some genetics can play a part. I have heard that some goldfish have a "disease" that keeps them of growing their normal size. 

By no means I know about genetics, etc...just based on what I have seen and the little I know


----------



## JanS (Apr 14, 2004)

Good topic PG!

I do think tank size comes into play, especially with larger fish. I've even been told that Cory's won't grow to their full size if they are hatched in a breeding net, opposed to a regular tank of their own from birth.

I think other factors in growth include how nutritious a diet they were fed during the crucial growing out period, the water quality they were raised in, and in part genetics.

Sometimes those things are irreversible, but sometimes you can bring them back with a good diet, and lots of care. 
Another common cause for many fish to become stunted is if they are carrying a parasite load, so unless I get the fish from a friend, I usually worm them when I get them to get them off to a good start.

I do think that those things will also shorten a fishes life span to a point. If their growth has been suppressed, they most likely aren't as healthy as they could be and may not live as long. Sorry to say, even with your Clowns, once they start getting too crowded in the tank, it's probably going to reduce the number of years they will live. However, if they aren't growing too fast right now, they could be fine for quite some time.


----------



## Piscesgirl (Feb 25, 2004)

Ok here's what I'm talkin about -- the picture of the two males face to face. They came from the same source and therefore are related very very likely, and the little one may be younger, but is a fully colored up male. The 'large' male is my killie I call Baby and he's only a few months himself.


----------



## JanS (Apr 14, 2004)

Wow, that's a huge difference PG.... I think that your more spacious tank must be playing a big role in the size and health of the fish. Even though many get by with it, I always like to opt for bigger living quarters, and if I can't provide that, I don't get them.....


----------



## kennyman (Oct 19, 2005)

I saw an interesting post on this subject by a pretty experienced fish keeper. If you scroll down a few posts to "Dan's" you can read it as well.
http://www.badmanstropicalfish.com/message_board/messages/231/48226.html


----------



## Piscesgirl (Feb 25, 2004)

That's a good read, Kennyman, thank you. The interesting thing for me is that people use that theory for big fish like Clown loaches, but when you look at my tiny Killifish, you learn that is the norm for Killifish (and Bettas really). They keep them in small tanks and don't think that's cruel. Why is it good for the goose and not for the gander? What is the difference? Is it the lesser lifespan for the Killies and Bettas that make it not cruel? I'm not sure.


----------



## SnakeIce (May 9, 2005)

how many bettas do you hear about people owning for more than 5 years? I came across one persons description of a number of individually named bettas, with houseing descriptions, that all lived more than 5 years and some were working on 10 befor they passed on. Every one of his betta tanks had power filtration, and were 5 gallons or more. 

Even one that his son had taken to college with him, survived all that, and was back at home still going strong at 7 years old.

say one rigged up a continuous water change betta cup, that would solve water quality but the restriction of ability to move would eventually prove detrimental to health.

fish health is about three things: water quality, good nutrition and room for the fish to be active in. Sometimes that last one requires some inovation to keep things interesting so the fish doesn't just sit in one place if that isn't typical healthy behavior. 

Even fish that sit still alot, say plecos, might need the larger quarters so water quality doesn't suffer as quickly.


----------



## New 2 Fish (Dec 31, 2004)

That was a really good article. I ran across a post somewhere about chemicals that fish excrete which will inhibit their growth. I'm not sure if that's true or not. I try to be very careful about which fish I put where, but I just mistakenly bought some scissortail rasboras that will get too large for my tank. I'll be taking them back tomorrow and taking a trip this weekend to get some lemon tetras for another tank!


----------



## Raul-7 (Feb 4, 2004)

New 2 Fish said:


> That was a really good article. I ran across a post somewhere about chemicals that fish excrete which will inhibit their growth. I'm not sure if that's true or not.


I'm not sure, but I think it refers to marine fish, such as the Boxfish which secretes toxins into the water when stressed.

As for the question, I'm not too sure about that because when I first started out (before I had access to internet or books) I kept a single adult Anglefish in my 5.5G for 6 years (rarely any water changes and almost no plants) who died when I acidentally dropped him onto the bathroom floor while cleaning out his tank. I'm not sure if it was luck that he survived all that time, but maybe he managed to adapt to the horrible conditions.

So maybe it's a case of how well a fish can adapt to it's surroundings?


----------



## Aaron (Feb 12, 2004)

PG, 
It's hard to see the little guy in the pic, so it is hard to tell if he is stunted or not. Usually, stunted fry or juveniles will have disproportionately large head, eyes and finnage when compared to full grown animals. There is the possibility that your new aquisitions may not be stunted at all. Consider that your original baby male grew up in a tank with his father. A younger, smaller male will not show his true colors, nor will he develop longer finnage in the presence of a dominant male (his father) in the tank. Now that he is larger, and compete for dominance, he can afford to show off his "true colors". 
In a group of fry, the dominant fish in the group will eat more, get bigger and if they are males (usually the case) will color up more quickly. In many killi species that I've worked with, One has to pull out the large dominant males as they show up, then another fish colors up and assumes the role. This pretty much happens to a lot of different types of fish like dwarf cichlids and betta sp. 
Perhaps your new aquisiton is just the "pick of the litter" and was the first of the group to color up? Did you ask the person from who you got them how old they are? That would give you a better idea if they were stunted or not.

Regardless if they are stunted or not, treat them well with clean water and good food and they will live a natural lifespan.


----------



## Piscesgirl (Feb 25, 2004)

The other fish in the picture "Baby" (the large one) is also with his father, and is just as large -- grew up with him. The two original females are just as large. The two new females and new male are extremely tiny, although I suspect they will start to grow in the larger tank. No, they don't look disproportionate. Baby was larger than the new additions even before he started getting his color. 

I hear all about stunting, but I still have my questions. There is no doubt in my mind now that killies are stunted by the small tanks they keep them in -- the question is whether that hurts them or not.


----------



## RTR (Oct 28, 2005)

IMHO, stunting's long-term effect is quite variable from fish to fish and is likely species-based. Clown loaches are extremely long-lived as is well known. but the oldest I have know personally was severely stunted, living out its life in a 20-long loaded with wood, rocks, and Java Fern. The fish might have died prematurely, but in its 30s is not bad at all. 

On the other hand, puffers which I underhoused (in the distant past before I knew better) stayed small and died young. Was it the stunting,or general care? I suspect the former. They (other than the dwarfs), should be quite Cichlid-like and make it to their teens.


----------



## Piscesgirl (Feb 25, 2004)

Wow RTR, what size what the clown? a 20 long? :shock: 30 years? :shock: 

Another thing that haunts the back of my mind is that most of these clowns probably would not have lived very long if purchased by someone else. I live in a very rural area that is not very animal-advanced, fish or otherwise. I purchased three of the clowns from Walmart (in my town), and the other two from Petsmart (in another town). That might even be said for many many other fish in the hobby which are purchased by newbie fishkeepers who get out of the hobby after their fish die. I suspect the number of experienced fish keepers isn't as great as the number of newbies that purchase fish....but, that's just my haunting thought...my clowns have probably all outlived their tankmates....


----------



## RTR (Oct 28, 2005)

Small, maybe 4" standard. The last decade plus was solitary, maybe longer. Not my fish, a local tank buddy. The clown tank occupied the breakfast table...

I do agree that most hobby fish die prematurely for poor care or lack of care. Too many of my tanks currently are geriatic havens for oldies but goodies. What else can you do with a teenage mbuna who outlived his tankmates? He gets a retirement home of course.


----------



## Piscesgirl (Feb 25, 2004)

awww RTR's retirement home for geriatric fish.


----------



## Algae_Grower (Mar 31, 2005)

http://news.bbc.co.uk/1/hi/uk/414114.stm

43 year old goldfish kept in a bowl for the most part of its life its dead now but still lived a long life though it does look stunted


----------



## Piscesgirl (Feb 25, 2004)

Awww poor guy  He does look stunted; but then again, I'm sure he way outlived his peers.


----------



## RTR (Oct 28, 2005)

Most cichlid keepers are quite familiar with pheromone/hormone stunting in groups and the need to size re-sort several times and use large frequent water changes to keep growth at all even. That is not at all the stress response chemical of box-and cowfish. It is strictly a growth control among siblings or comparably sized conspecifics. I am unsure of how much it crosses between relalted species of fish of other lineages, but someone up on breeding Cichlids may be able to offer more recent info.


----------



## ann (Nov 4, 2005)

I think food and water conditons play a huge part. A few years back while I was still at school I used to work part time at a barramundi breeding farm. We would keep thousands of 1-2cm fish in the large above ground pools. The fish would get fed about 10 times a day with as much foos as they could eat until they stopped actively feeding. They also got a water change just enough to replace the water removed from cleaning uneaten food from the ground. But the key to getting all the fish to a larger size was separating out the bigger ones. Every two days the fish would be size graded and placed in separate tanks. This is true of aquarium fish too. If bigger ones are not removed they compete for food with the smaller ones. And i have been told but people in the live fish industry that for a lot of fish species if they are under fed in the first few months of life may never reach the same size and fish supplied with abundance of food.


----------



## Jeff Kropp (Apr 25, 2004)

Piscesgirl said:


> Will my killies have a longer lifespan in a larger tank -- all things being equal?


I would guess that generally more area might lead to larger size fish because it is commonly held that very deep ponds are neccesary to raising competion sized koi. Yet I have noticed that some species do not appear comfortable in large sparsely populated environments. For example a single gold ram in an empty 20 gallon tank often loses its will to live regardless of provided water and food quality. Perhaps its not simply a question of volume but one of optimum population density for the environment?

With many species of killie long life is not an obvious survival method. They have adapted to living in temporary water holes and measure their evolutionary success by the survival and distribution of their species over many generations. The longetivity research I have read about, seems to point towards caloric restriction as the most effective means of extending lifespan but I can't say thats been true of my fish keeping.

In my experience, water quality is consistently the single most important variable of aquatic husbandry. As regards these forums... I have come to correlate the high nutrient levels often used to produce fantastic looking tanks with reduced fish health. Its a trade off, great fish health or great looking massive quantities of plants, that we must each consider.


----------



## [email protected] (Jul 18, 2005)

*Nature*



Piscesgirl said:


> Ok here's what I'm talkin about -- the picture of the two males face to face. They came from the same source and therefore are related very very likely, and the little one may be younger, but is a fully colored up male. The 'large' male is my killie I call Baby and he's only a few months himself.


Animals find a way to adapt to there ever changing enviroment in nature, the same holds true in the man made "natural habitat" we just notice these changes more when they happen under our nose. As for your fish if their tank is well taken care of and they seem happy don't worry. If and when your fish get to big for there current home you have an excuse to upgrade.


----------

