Tang Police or Tang Nazis?

[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.

[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.

[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.

[Lance]

Originally Posted by Aquattro

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.

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.

[Aquattro]

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

[Lance]

Originally Posted by Aquattro

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

Who me????

[asylumdown]

Originally Posted by Lance

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.

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.

[Lance]

Originally Posted by asylumdown

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. 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.
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.

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

[Youngster Dan]

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

[Mrfish55]

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