[CaptainK]

Hi Everyone,
I was in deep thought last night while looking at my tank and came up with two questions:
1) When us humans go underwater we are exposed to the weight of the water around us. Seeing that most of the fish we collect in our tanks are a lot smaller than us, what keeps them from being crushed from the weight of the water?
2) I don't ever recall hearing about anyone losing a fish to old age. When it is a fishes time to go and meet its maker, due to old age, how does it die. This may sound like a silly question, I know.
But does it just go belly up and float or does it exibit signs of disease that we would think it be sick but is actually just dying due to old age?
Thanks,
CaptK

[Biomanjcs72]

The reason the fish don't get crushed is the same reason that we don't get crushed, our bodies simply absorb the extra pressure as a function of the pressure of dissolved gas in our blood. (Find a scube site, see "the bends") Most of the fish "collected" people in the industry are taken from less than 30 feet of water. Past that, they have to slowly bring the fish up over a period of several days, that becomes too time consuming, so that's why we don't usually get deepwater fish.

Some fish die of old age the same way we die of old age, their bodies lose the ability to fix stuff that goes wrong (same way with humans) They lose scales, etc., infection moves in and they eventually die. I have a Clown Loach (FW) that I've had for 7-8 years, he's big, and healthy as a horse. That's fairly brief, I left a few holes in there, but that's the basic gist of it. HTH

JCS

[mgk65]

In aging, for higher order life forms like vertebrates (fish, homo sapiens, birds, etc) the DNA degrades as each cell is split during growth. Eventually the cells cannot split and die, causing aging.

In lower order life forms (trees, crustaceans, echinoderms) the DNA does not degrade, allowing them to live indefinately.

mgk

[organicreefer]

mgk are you sure? i find it hard to believe that my sally light foot is immortal