Agreed. I guess my side of the fence feels that even though I've made peace with what I do, I'm not going to try and justify it with some story about research or saving fishies from sharks :) I am not a friend to the fish of the world (I eat tuna every day), but I'm ok with that.

Interesting read.

I only have one little issue with the article, with regards to measuring cortisol levels in the fish. It was stated that there wasn't really a difference in cortisol levels between captive fish (at various tank sizes) and fish in the "field". Now, I'm assuming you have to actually handle the fish to get a blood/cortisol sample?

Wouldn't the actual act of catching the fish induce stress (ie elevated cortisol) and so this stat is completely misleading? As every fish being tested is at an artificially elevated level of cortisol, and it being nearly impossible to take a baseline measurement?

Good catch Dan! :)

I haven't read the article yet, but in my field (primate studies) we measure cortisol in feces and urine, with urine being the ideal source (try running through the forest with a giant funnel held over your head...). It's one of the easier hormones to study because of that fact actually. Not sure how they got their sample, but it seems to reason that they can probably get it passively

Absolutely. My thoughts as well. I personally believe a fish is better off in the ocean than in my little pretend reef.
Buuuuuut, just to mix it up a little: How do we really know our fishies aren't perfectly happy in their little glass boxes. If we provide them with good water conditions, a healthy diet, suitable tankmates and hiding and swimming areas, they may after all be tickled pink. Fish pretty much run on instinct, and instinct says: eat and don't be eaten. I can provide them with that. So who the hell really knows? I don't pretend to.

Interesting that 4 pages of debate have happened over an article with a single reference that isn't even relevant to the fish we keep. What base line is drawn for showing stress? Are there any other types of fish that this was tested on? The article is a lacking allot of scientific structure.

100% agree.

Tang police, well my opinion is their overall effect may be that the average captive tang's swimming space will be marginally larger when compared to a tang that remains in the ocean.

Disclaimer: I have 2 tangs in my tank that is aproximately 130 gallons. If I can afford to, within a year and a half I will upgrade to a 200ish gallon tank.

Lance, don't you think you've caused enough trouble for one day?? :)

It may take a while before the cortisol level rise after a stress so they might have had plenty of time to take a sample without getting a stress response right away? could be.

then it could be that the fish returned to a normal level of stress after being handled so the stress hormones did not really rise. Maybe it take a constant amount of stress for this hormone to really show higher?

just my thoughts on it as I was wondering about the same thing when I read it.

statistics, well, they are just statistics! use them to create an argument/article and then defend it.
one can use this stat to show that fish are under constant stress...captive, in nature, or while being handled.
all i know is that the sale of tangs have increased dramatically since this thread was started:lol:

Well, surely beat the tang police assumption that a tang is stressed in a 90 gallons as they have absolutely zero reference or study to back it up, just their own personal assumption :)

This article may have only one reference, plus the personal experience of the aquarium administrator who wrote it, but it is interesting reading and informative, not just biased opinion.

I was happy to learn that a hippo tang does not cover thousand of kilometer a day in the ocean...as I was mearely told by a lot of people and which was the main argument against keeping a hippo tang in a smaller tank than 180 gallons.

I know we can't ever truly know the mind of another creature, but in primatology, trying to figure out the level of intelligence of other animals is sort of the name of the game, and I think we've gotten pretty good at it. I think animal owners and lovers have a tendency to anthropomorphize their pets to an extreme degree. I don't think that the fish we keep are swimming around in their tanks, waxing poetic for the days when they swam free on the reef.

Primatologists work with animals using something called an ethogram, which is a list that attempts to exhaustively catalogue the entire behavioural suite of an animal in the most basic functional units. Generally speaking, the smarter the animal, the longer the ethogram. The most exhaustive ethogram for chimps that I've seen was literally hundreds of pages long, a human ethogram would probably be in the thousands.

I think if I were to try and make an ethogram for a tang, I'd probably be able to make it to half a page, if I was being rather liberal with my categories. Fish have behaviours that they can and need to exhibit. If we put them in a circumstance where they are unable to exhibit those behaviours, they will probably get stressed out, but they're not going to be thinking about it. The best we can do is to try and replicate their environment as best we can, but if we can't, the fish is not going to have a complex emotional response and sulk while it thinks about what it would rather be doing. The fish we keep react to stimuli and conditioning, that's pretty much it. My last tang was too busy attacking it's own reflection when I kept the sides clear of algae to consider that it's tank was too small. However, it was clearly too small for that fish and it exhibited behavioural problems because of it (so it's gone to a much larger home now). None of the other fish in that system have major neuroses, unless I do something that makes the environment incompatible to them (say, put them with tank mates they will fight with).

If there is a problem with the environment they are in, the fish will react negatively. They will get overly aggressive, or they'll stop eating, or they'll get sick. If they're not doing any of those things, there's a good chance it's emotional state is as level as it would be anywhere else it wasn't getting eaten.

Keeping gorillas in cages however, is a totally different story.

Who me????

From what I know, cortisol levels in the average fish reach the highest levels around an hour after being stressed.

Bingo! That's what I was trying to say! Well, I did say it, just not nearly as well. :lol:

Asylumdown, cool posts! I have never heard of an ethogram, but sounds like you do some really interesting stuff.

I take it you were bored today Lance? Now I feel guilty, going to have to get a bigger tank now, thanks a lot!

...... and for his next trick Lance will have us all discuss the question "is God really there""

both fish are presumably caught and handled so that effect should not be a confound. If they can see a difference, and there's no change to their baseline measures (while they might not be true baselines), then it's a fine measure.


And the citation is more than likely to be generalizable to other fish - besides, it certainly isnt the biggest generalization of the literature. Assuming one large ref dwelling genus with a similar behavior acts and responds similarly with Tangs isn't a bad assumption.

ROLMAO

+1. I would like to see this actual test. Anyone have a link? A lot of science talk in here.

Is anybody willing to create a poll listing off the number off fishes that you ESTIMATE that you have bought and died while in your care? If I were to create this poll, I wouldn't even give the option of 0-10 because that is not realistic. And whatever choices anybody made, I would multiply by 1.5 to get the more accurate true numbers.
Put it bluntly, we all contribute to the practice of sacrificing animals for entertainment. So regardless you give the fish a 50 or 100 or 200 gallon tanks in comparision to their natural habitat, we are only trying to reassure ourselves that we are doing the right thing.

Oh NO, don't do it....

+1

I do advocate for tangs to have a decent sized tank to swim in and I often recommend at least a 90g for smaller tangs like koles/scopas/yellows and 180g and up for larger tangs and even more space 8-10 feet long tanks for naso tangs. IMO a baby tang under 2" is not going to need as much room to swim in as when the tang gets larger (over 6") so if you want to keep a baby tang in a smaller tank and plan (and actually do) re-home it then go for it, however the problem is when the person gets attached to the baby tang they have in their small (say under 40g tank) and the next thing you know you see a 6-7" tang who is the same length as the tank they are in, which at that point I will get on a soap box and say that isn't right. However I have seen the smaller tangs koles and scopas in 45g tanks and they seem perfectly fine and healthy so I while I would recommend a 90g to that person I am not going to freak out on them, however if it was a 8" unicorn tang in a 45g I would, but one of the smaller tangs no.

Now I am far from perfect and even admit that while I think bigger/longer tanks for tangs are better I have a 230g which is only 6 feet long and I do plan on adding a blonde naso to it. So really I'm not much better then the person who keeps a yellow tang in their 40g tank. This is a bit of a selfish hobby and while I do believe you should try to do you best to provide a decent home for the fish, there are times when we talk ourselves into adding a certain fish that we know might not be "ideally" suited to our tank.

A quote from the article "The members of the genus Naso and Prionurus are the true open water swimmers; they are the ones that require special consideration." I have to agree with this 100%. When I was cycling my 230g reef tank I saw a great deal on a naso tang he was 2-2 1/2" and I knew I wanted to add a naso to my 230g reef, so the deal was to tempting to pass up. However at the time the tank I had available to house the small naso in while the 230g finished cycling was a 30g cube :surprise: I knew it was wrong to put a naso (even a small one) in a 30g cube but because I knew a had a bigger home for him to go into in a few weeks I talked myself into it being ok. He was in the 30g for 2 months before the 230g reef finished cycling and he was a dark grey stressed out colour the whole time he was in there. He also swam speractically all over the tank, at the time I convinced myself that he was eating so he was fine. However I didn't even realize the colour change and the (IMO) stressed out swimming patterns until I transferred him to the 230g. After the transfer he was no longer a dark blotchy pattern colour and changed to a lighter solid grey colour and he no longer did jerky swimming movements, he swam across the length of the tank and IMO seemed significantly less stressed.

I think this part of the article is important to point out, so that people do not get the wrong idea from the article "Hopefully you don’t think that I advocate keeping fish in overly-small aquariums, as I do not. I always strive to give my captive fish the best possible environment. The exhibits I use for tangs at the public aquarium where I work range from 450 to 1,300 gallons. What I am advocating for here is a more civil discourse, more careful consideration of measurable husbandry parameters, and less reliance on subjective personal opinion."

Sorry, I'm going to disagree with this. Though my disagreement is purely trivial, as it seems the cortisol levels are likely measured passively by collecting it from fecal matter, and not from being handled.

I doubt cortisol levels are being added on top of each other like you suggest and you cannot simply take levels from one group and subtract it from another. For example, consider you and I have the same level of fitness and I am sitting reading articles on canreef and you are currently going for a jog. You will have a higher heart rate than myself. Now, imagine that we both have tangs in a small tank, and the "tang police" are out for blood and decide they are out to get you and myself. Both of us will sprint as fast as we can to get away from nasty insults and condescending attitudes of the tang police! If you were to then measure our heart rate after we have been sprinting for a while, our heart rates would be similar despite the fact that you had been jogging whereas I was sitting. So, from our sprinting heart rate data alone it would be impossible to determine what our "baseline" was.

Perhaps a silly example, but that is just how I interpret it.

Only one for me since I started a year and half ago and that was a green mandarin that was killed by a yellow tang :(

I sold the yellow tang. Shame because that green mandarin was with me since the begining and was fat and healthy eating white worms, bloodworms and fish roe. I have the female remaining but never again a yellow tang for me.

Now the most important thing in my tank is no aggression and any aggressive fish is sold.

The worse thing to do to fish is not doing quarantine and letting them live with parasites.

If we find him, we can ask for his opinion on this subject. And while we're at it might as well clear up the "Which came first, chicken or egg?" question.

http://www.reefmonitor.org/documents...rinol.%202.pdf

They do an assessment of cortisol and corticosterone levels from fecal matter, and find that baseline levels of aquarium acclimatized fish and reef dwelling parrotfish are not statistically different.

As for the testing of fecal matter vs direct (blood) measurement, they do both to validate the former method, and find that pooling fecal matter is an acceptable and useful metric for assessing stress hormone levels.

Is Wayne (Naesco) on holidays?

:lol:

A couple of things that seem obvious to me:
> When we're talking about whether a yellow or Kole tang would be happiest in a 90 gallon or a 150 gallon, I agree we're splitting hairs. The trouble with studies like this is that a newbie to the hobby will see this and figure the LFS was right when they were told they could put a Naso tang in their 20 gallon.

> As for the article, I think a lot of you missed what felt like the most important part to me. Going by Gallons, is like the inch of fish per gallon rule. His example was "My car gets 500 pounds to the Mile", it just doesn't work. What this guy is advocating is a "swiming space" measurement for the simple reason that you could have a 150 gallon "Tall tank" with some crazy measurement like 12long x 12wide x 8 feet tall and it would satisfy the "gallonage" rule but still be a horribly inappropriate for any kind of swimming fish. Likewise you could have a shallow reef that was 5 or 6 feet long, but shallow and not a lot of depth and provide the swimming room appropriate for larger fishes but fall below the "Appropriate Gallon Rule". His other beef is with "Tang Police" not caring about other fish like wrasses who also need a TON of room. Most importantly, he does NOT advocate a lack of standards when it comes to housing fish, just that the gallon rule most frequently used by the TP is not the standard we should be using. Also, worth noting in the scientific study he noted that it was sub-adult parrotfish being studied and not full grown specimens.

Finally, I find the attitude that since you already took it out of it's natural environment and put it in a glass box therefore you have no responsibility to provide an appropriate environment, to be an incredibly ignorant sentiment. If you enjoy steak, does that mean you shouldn't be concerned about whether or not beef cattle are grown appropriately, or be disturbed when you see abuse of animals? If you're driving along on a road, does the fact that the road already destroyed the environment it sits on make it acceptable to throw your garbage out the window?

Our hobby is destructive, there's no if's and's or but's about it, that said it does not absolve us of the responsibility to care for the creatures in our possession and to do what we can to mitigate the negatives by purchasing captive bred when possible, passing on fish that come from areas with shady collection practices when buying wild-caught, buying frags from fellow hobbiests as opposed to wild-harvested from the LFS, etc. Failure to do so will sooner or later attract attention from those who only see the negatives in this hobby and will result in more laws trying to be brought in like the one Vernon BC recently attempted which would restrict our ability to enjoy this hobby.

A lot of people will always do a lot of stupid things regardless of what they read or are being told. I don,t see how this article would advocate to a newby to buy a naso tang and put it in a 20 gallons especialy that they state the opposite mentioning that they are the exception needing lots of room.

wierd you got the opposite idea from it.

I don't know how the whole tang police thing started. I have never seen any evidence of tangs being stressed in a reef tank, due to spacial limitations. The other claim that I don't understand is that tangs need high water flow.

Marine fish do best in smaller tanks (1-20 gallons) with respect to wholesale and retail facilities. Retailers that use large holding tanks (30-150 gallons) cause more fish injuries, fish-to-fish disease transmission, aggression, and trauma as they are netted.

The reef structure design is more important than the actual tank size. I agree, wrasse can cover a lot more territory in a short time tan any other fish. They have well developed swim bladders so they can dart up and down as well.

The egg of course, duh, doesn't every body know that?

Way to go Lance you DINK!!!! now every one is so honed in on this thread nobody gives a crap about my build thread.......


:mrgreen:

Sweet Louise someone burn the soapbox, dismatle the pulpit, steal the microphone, turn the lights out.....These type of threads make me howl......We all keep fish in boxes, no one is any better than the next...get over it...lol

What thread? You had a thread?

Now, now Mike. We're paying attention. Deltec skimmer; no make that a MRC. LED lighting; no make that 4x250W MH; no make that 3x400W; no make that 3x250W and 1x400W. See, I'm following your build thread. :mrgreen:

Don't forget about the two guys with some big wood.

:pound: