Tang Police or Tang Nazis?

[daniella3d]

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.

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?

[don.ald]

Originally Posted by daniella3d

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

[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.

[Mandosh]

Originally Posted by daniella3d

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.

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