Tang Police or Tang Nazis?

[paddyob]

Originally Posted by Youngster Dan

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?

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

[Chin_Lee]

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.

[globaldesigns]

Originally Posted by PoonTang

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

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

[fishoholic]

Originally Posted by lastlight

*lays a man-slapping on lance*

+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 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."

[Youngster Dan]

Originally Posted by shrimpchips

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.

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.

[daniella3d]

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.

Originally Posted by Chin_Lee

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.

[Lance]

Originally Posted by PoonTang

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

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.

[shrimpchips]

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.

[MitchM]

Is Wayne (Naesco) on holidays?

[Lance]

Originally Posted by MitchM

Is Wayne (Naesco) on holidays?