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