Goldfish Growth Inhibitor...very Discouraging Options

[junkeatng]

Hi All,

Gong Xi Fa Cai to all those who are celebrating Chinese New Year.

I came across this very interesting article about goldfish growth and the factors affecting it.

It is a very 'scientific' article but from what I can derive (from my limited scientific mind), it indicates that goldfish tend to experience growth spurts at the beginning of spring after a cold spell. If that is indeed true, it could well mean that here in the tropics, we may never grow our goldfish to the sizes attainable in more temperate climates. Now isn't that discouraging???

Please comment...in particular Doc Goldrush who may be able to shed more light on this topic.

[bekko]

Oh.... My head hurts.

I think the authors began their deliberations with the assumption that all goldfish have a winter dormant period, a spring spawning season, and a summer/autumnal growing season. They used the physiological changes that take place when coming out of winter dormancy as clues to guide their studies on regulation of growth hormone release. But, they never said that a winter dormancy is necessary for the release of growth hormone.

In warm climates, goldfish grow year-round. They do not have to shut everything down for winter. You could argue that growth hormone is always available so goldfish should grow larger in the tropics.

There would need to be a controlled study to address this issue directly to find out for sure. My wild guess is that annual growth rates in tropical and temperate regions are probably pretty similar.

-steve

[goldrush]

The abundance of food available corresponds to an increase in growth rate and conversely a scarcity of food reduces it.In temperate countries which experience the four seasons,the growth rate of fishes experience periodic growth spurts due to availabity of food as well as the rate of metabolism which indirectly is temperature dependent.For example in the summer,the higher rate of metabolism together with their higher capacity to consume food which is now abundant will inevitably result in a sudden growth spurt.In the tropics like ours which doesn't go through this cycle,our fish tend to grow throughout the year incrementally.Perhaps there is no dormancy and inactivity here that we are unable to detect a sudden growth spurt as seen in fishes reared in temperate zone.

[junkeatng]

Interestingly you mentioned that annual growth rates in the tropics and temperate countries should be similar. I always assumed that goldfish grow more quickly (though not necessarily larger) in the tropics...hence their shorter lifespans.

[bekko]

Yes, you are correct. If you look at the first 12 months, fish in the tropics are larger. The difference is less dramatic at the end of the second twelve months and the difference may disappear at the end of the third twelve months.

-steve

[nygold]

What I got from the article was the spring showed the greatest growth rate.
So if one could trick his/her goldfish into thinking it's spring when ever he/she want's he/she
can grow a large fish very quickly.
Even in the tropics people still speak of growth spurts.

Finding a way to triger these spurts could be the key to growing fish large and quick.

[clm2206]

What I got from the article was the spring showed the greatest growth rate.
So if one could trick his/her goldfish into thinking it's spring when ever he/she want's he/she
can grow a large fish very quickly.
Even in the tropics people still speak of growth spurts.

Finding a way to triger these spurts could be the key to growing fish large and quick.

Maybe cooling down the water temperature (fan or A/C) for 1 month and then warming up with heater?

This post has been edited by clm2206: Sat, 07 Feb 2009 12:00 pm

[nygold]

Maybe cooling down the water temperature (fan or A/C) for 1 month and then warming up with heater?

I was thinking more along the lines of the tanks they sell live lobsters in the have
built in refrigeration units.

[clm2206]

I was thinking more along the lines of the tanks they sell live lobsters in the have
built in refrigeration units.

Do you mean chillers?