Stress and Healthy Diets

[John D Hirsch MD]

I don?t know how many of you saw the recent report on the effects of stress on human lipid profiles. It has long been recognized that diet and exercise can have a positive impact on health, cholesterol and lipid levels. Medical science has now added stress as a risk factor. Stress is mediated in all animals by stress hormones. Acute stress is mediated via a group of hormones call catecholamines, like epinephrine. These are the ?fight or flight? hormones. Chronic stress is very different metabolically from acute stress. The hormones that mediated chronic stress are glucocorticoids or steroids. All stress hormones are catabolic meaning they ?burn the walls down to keep the fire going?. Stressed animals may be eating but their diet rarely provides adequate nutrition to meet their metabolic needs. Proteins, for example, are diverted for either structural or functional purposes and are burned for energy. Those body functions that use large amounts of protein slow. Mucous coat production, immunity, and gastrointestinal functions are affected first.
In the eat or be eaten world of the wild, all fish must live with some degree of acute stress, but our closed ecosystems under the best of circumstances must produce a certain level of chronic stress. Water quality, water temperature, waste disposal, lighting, habitat, diet, and neighbors all are potential stressors. Stressed individuals are more prone to injury with poor healing, infections, infestations, and death. Creating the most stress free ecosystem is a challenge for each individual hobbyist. My hat?s off to Paul B. and any hobbyist who can observe spawning in their tanks as that, in my opinion, is the ultimate definition of Health. Diet is just piece of that puzzle. My guess is that some or all of the diets of a spawning pair have an all-natural component.
Doc

 

[reef.right.corals]

All of my fish are spawning, and I feed them SPAM. Just kidding. However, I also think it's interesting how different species react to stress. There is a great deal of difference between how a wild-caught clownfish reacts to the rigors of aquarium life when compared to how a Moorish idol or Achilles tang does.

 

[Paul B]

These are good points. We react to stress much differently than fish do. As an example we can be in prison, hang gliding, dying of parrot fever, or being held in a jungle hut by Amazons or gorilla's and we will still be able to reproduce. It will have no impact on our reproductive functions. (unless they are very ugly gorilla's) But fish are built differently. Our fish are always under some sort of stress because we keep them confined in most of the time, fake seawater, place them with creatures they have never seen, feed them things they are not used to, circulate water around them in the same exact way every day, light them with totally different lighting spectrums, and in most cases, totally ignore moonlight which controls many fish functions, keep them in very shallow water as all fish come from much deeper water than our tanks, and yes, they know that, which is why we never see tangs, angels or manta rays in 16" of water. We never take into account that they can see us through the glass but they can't see the glass itself which I am sure drives them crazy due to their lateral lines that prevent them from crashing into things. (I also believe this aspect is what causes HLLE but that is only my opinion) There are three functions of fish that controls their life. Growth, reproduction and immunity. These things all require certain food "and" a certain level of stress or lack of it. (CERTAIN FOOD IS NOT NECESSARILLY SOMETHING THEY WILL EAT) The first thing that goes is reproduction which is why very few fish in captivity spawn as in the sea, fish are "always" pregnant. The next thing that goes is immunity which is the reason for all the disease threads. Fish in the sea probably never get sick except for the occasional headache. Last it is growth. In a tank almost all fish are stunted. I realize this is a controversial subject but I have kept many tangs and copperband butterflies for many years and virtually none of them ever reached their normal size in the sea which is about 9" for both those fish. My 24 year old fireclown is about 4" long and I am sure in the sea they are double that size. That fish is constantly spawning so I know he is very healthy.
All of my paired fish are spawning so, for some reason, either on purpose or accidently, they are healthy and have a low enough level of stress that allows them to be in that condition. None of them were ever sick and none of them were ever quarantined which is another indication of health and a working immune system.
These are just my opinions as I am not the God of fish.

 

[marrone]

Last it is growth. In a tank almost all fish are stunted. I realize this is a controversial subject but I have kept many tangs and copperband butterflies for many years and virtually none of them ever reached their normal size in the sea which is about 9" for both those fish.

If you feed you fish correctly, and have good water conditions, there isn't any reason that most fish can't reach full size. Now it may not be as large as in the wild, but fairly close. I have had many Tangs, Triggers, Groupers, Angels, and even Damsels that have gotten very large over time, maybe not as large as in the wild, but very close. I think stunting fish is something that happen more in freshwater than saltwater.

 

[Paul B]

That's why I said it was controversial and if I remember, your tank is much larger than mine.

 

[marrone]

But tank size shouldn't really matter, as long as the water conditions are good and the fish is being feed a correct diet, it will grow. I brought a LT Tang, about the size of a quarter, and put it in 90gal reef tank and within 6 months the fish was fairly large and a few month later has out growth the tank. Stunting is much more common with freshwater fish, not so much with saltwater.

 

[Paul B]

But tank size shouldn't really matter, as long as the water conditions are good and the fish is being feed a correct diet, it will grow. I brought a LT Tang, about the size of a quarter, and put it in 90gal reef tank and within 6 months the fish was fairly large and a few month later has out growth the tank. Stunting is much more common with freshwater fish, not so much with saltwater.

But tank size does matter. Some fish I have to agree will grow out of the tank no matter what you do. A New York flounder will grow out of a tank as will a sea robin and a tropical remora. (I have kept them) I had one of those things and it grew so fast I could hear it grow. But some fish, in some tanks will only grow to a certain size no matter how healthy they are. My fish are spawning and that is as healthy as they can be. Some of them are also in their 20s. My copperband is about 5" and has been in my tank a couple of years. He was as big as a quarter when I got him. I do not think he is still growing and if he is, it is very slow. My first tank was 40 gallons and I had a hippo tang in there for about 5 years. He was about 4" long. Then I transferred him to my current 100 gallon tank where he quickly grew another inch even though I had him about 10 years, he never grew any larger. Again, I am not sure it happens with all fish, but I am certain it happens with many. We can go on all day about this and I am fairly sure there is no way to prove it with all fish.
You are correct about some fresh water fish. I know you can put a tiny goldfish in a bowl and in ten years he will hardly get any larger and in a lake they can grow to a foot or two.
Fish in the sea grow huge. Take clownfish for instance. I have never seen one in a tank grow as large as they do in the sea. They get huge. Tangs grow to about 10" and they get to that size very quickly. Copperbands get about 9" as do long nose butterflies.

 

[marrone]

We're talking about stunting fish, not the fish being too large for the tank. If feed correctly, and with good water conditions, a fish will grow to as large as it can and the size it should be. Now it mayn't get as large as a fish in the ocean, but it should get big. So, if you have a fish, that gets very large, and it doesn't in your tank over the years, then you're probably not doing something right. Now you see adults of some fish come in from wild fully colored and with all their adult markings that are actually smaller than some Juv of the same species, with a lot of this having to do with diet and habit that they're coming from, which you can say the same with you own tank if a fish doesn't get as big as it should, or at least large.

As for the size of tank playing a factor, well that also has to do with the larger tank probably having better conditions, both water and stress on the fish. Then again I have fish that are older than yours, and quite a number in their teens and twenties, that have gotten very large in smaller a tank then the same fish in a larger tank.
By the way, most of the larger Tangs will grow way larger than 10", as do a lot of other fish that we keep.

 

[Paul B]

OK, as I said, it depends on the type of fish.
By the way, do you still have that real large tank in your home. That was a really nice tank

 

[alie99]

I don?t know how many of you saw the recent report on the effects of stress on human lipid profiles. It has long been recognized that diet and exercise can have a positive impact on health, cholesterol and lipid levels. Medical science has now added stress as a risk factor. Stress is mediated in all animals by stress hormones. Acute stress is mediated via a group of hormones call catecholamines, like epinephrine. These are the ?fight or flight? hormones. Chronic stress is very different metabolically from acute stress. The hormones that mediated chronic stress are glucocorticoids or steroids. All stress hormones are catabolic meaning they ?burn the walls down to keep the fire going?. Stressed animals may be eating but their diet rarely provides adequate nutrition to meet their metabolic needs. Proteins, for example, are diverted for either structural or functional purposes and are burned for energy. Those body functions that use large amounts of protein slow. Mucous coat production, immunity, and gastrointestinal functions are affected first.
In the eat or be eaten world of the wild, all fish must live with some degree of acute stress, but our closed ecosystems under the best of circumstances must produce a certain level of chronic stress. Water quality, water temperature, waste disposal, lighting, habitat, diet, and neighbors all are potential stressors. Stressed individuals are more prone to injury with poor healing, infections, infestations, and death. Creating the most stress free ecosystem is a challenge for each individual hobbyist. My hat?s off to Paul B. and any hobbyist who can observe spawning in their tanks as that, in my opinion, is the ultimate definition of Health. Diet is just piece of that puzzle. My guess is that some or all of the diets of a spawning pair have an all-natural component.
Yes! i agree!