Prepping Tank for Betta
You do pose an interesting question here, about temperatures and fish in the wild. We will stick with the environment of the wild betas similar to yours. B splendens come from the Mekong Delta, and are found in swampy areas, flooded fields and some streams and rivers. They are generally found in quiet, still waters. The yearly averages run from 72 degrees F to 93 degrees F without much real variation between winter and summer. It is also very humid during most of the year. There is not much temperature variation in the water, since when living in flooded areas will stay warm from the heat of the earth, and it would take a lot of cool water from the rains to cool down the rivers significantly. While there is not much variation in the temperature of the water, there is some.
Now, consider, the B. splendens you are keeping. It comes from many years of breeding to develop the fins and color it has. There has been much inbreeding to accomplish this. While inbreeding will, indeed, concentrate the good genes–the genes for those traits you are looking for, it also concentrates genes that are not desirable. Among those can be, and are, the genes that control the animal’s sensitivity to temperature. This has been noted time and time again in many fish that have been bred for desirable traits. Often, you need to keep the fish at higher temperatures than you would for the same species that has not been bred for specific traits.
To a certain extent, wild fish can control the temperature of the water around them. Next time you go to the lake (or a lake) to swim, go out to where the float is. There the water is deeper, and you will be better able to feel the difference in the temperature as you go deeper into the lake by diving or jumping off the float, and heading for the bottom. Usually, it is significantly cooler the deeper you go. Compare this with your neighborhood swimming pool, should you have such a critter. If not go to someone else’s swimming pool. Go to the deep end and do the same dive. There is no significant change in temperature. Why? For one thing, the pool is constantly filtered, and the water flow is much higher than it is in the lake. For another reason, you have a higher concentration of critters (humans) in a much smaller body of water, constantly stirring it up and mixing the thermoclimes, until there is only one. Hmm, perhaps more like an aquarium than most would think, no?
These are the reasons why we try to maintain a certain temperature in an aquarium. The fish will be happier for it.
Now, having said all that, let me tell you about something I did several years ago–well maybe that should be a couple of decades, but whose splitting hairs right now? I had a population of green swordtails (Xiphophorus hellerii) in an outdoor pond (about 2500 gallons). They and some white clouds were the only inhabitants. Suddenly it was October, in New England! The fish were still in the pond. The water temperature was close to 50 degrees F. Pulling out my trusty seine and offering some free beer to some witless souls, we started pulling out hundreds of fish, still alive and kicking. I did several shows that fall, and all fishes were impressive for the judges and placed well. One thing you need to keep in mind is that Xiphophorus hellerii you usually see, at least back then, were the closest you could get to the wild populations, without truly having wild fish. The white clouds are more a temperate water fish, and may have survived a mild winter.
While I am at it, I may as well answer your other question, posted later in the thread than this message. Take a look at the swimming pool analogy, and you will understand why you cannot keep the various areas of the tank at different temperatures. The water is mixed to well by the filtration and the fish you may have in the tank. It is also a small body of water, so even without filtration, it would be difficult to try to maintain different areas of different temperatures. Now, if you were to put an addition onto your house, 20 feet long and 8 feet high, and 12 feet wide, you may be able to accomplish that goal with some fancy footwork of heater placement and water flow, but it still is not too likely, but think of the fish you could keep in there!
\Steve//
Category: Philippines Internet Koi Society
