RE: [GSAS-Member] Fish & temperature?

[welenofsky@comcast.net]

Well said Trish! Good observations!

-------------- Original message -------------- 

> Ok here is what I have experimented. Not as detailed 
> as Clay's answer, but a comment at any rate. 
> 
> I to do the "finger" test from the tap. Get it as 
> close to the tank as possibl. It is cooler water to 
> begin with as it takes awhile for the water to warm 
> up, becasue of the hot water tank being so far away. 
> When it is cooler, fish don't seem to mind the 
> difference. They still swim around. I keep mostly 
> Africans, so they are warm water fish. Keep the tanks 
> at about 80 degrees.....So maybe yes if the water was 
> ice cold, yes it could make a difference. But slightly 
> cooler, I would think not. If it goes a few degrees 
> one way or another, it shouldn't make to much a 
> difference. 
> 
> I have also had gold fish, and they had no heat. Which 
> they are a cooler water fish. Can survive outside in 
> ponds with water frozen over the tops of them! When I 
> did add a heater at one time, yes the fish were 
> somwhat more active, but it also shortens their lives, 
> as they prefer colder water. I had their temp at about 
> 75, with the heater. When they did not have a heater, 
> tank stayed at about 65 in winter and 70 in summer. 
> 
> Also when the temp is lower in a tank fish will eat 
> less, for their metabolism is slower, when it is a 
> warmer temp they eat more, and are more active. 
> 
> Example, when you swim in a lake, you will find some 
> places in the water, which seems very warm and right 
> next to it can find a place much cooler. Just as it 
> was said when this thread first began. 
> 
> So since it is this way in nature, why not in our 
> tanks as well to some degree. 
> 
> Like I said my comment isn't as detailed as Clays, but 
> it is what I have experienced. 
> 
> Trish 
> --- "Hess, Clay A" wrote: 
> 
> > Hmmmmmm, again, this is an interesting issue too. 
> > My experience with 
> > fish and temperature changes has been both good and 
> > bad. First, I 
> > should note that I change my water directly from the 
> > tap and check the 
> > temperature coming from the tap by fingertip (yeah, 
> > Mr Engineer uses his 
> > fingers, good to plus or minus ~3 degrees). Second 
> > I should mention I 
> > check my temperature to the Celsius scale (only 
> > because that is the type 
> > of thermometers I have). Third I will mention that 
> > I have fish from 
> > Asia, Africa and South America mixed in most of my 
> > tanks (Ack!! How can 
> > that be??) 
> > 
> > Soooo, ok, stick to the question please. Fish and 
> > Temperature. Oh 
> > yeah. Let's look at an example a little closer to 
> > home to see if we can 
> > draw some possible parallels to the aquatic world. 
> > How about people? 
> > You, me, the kid next door....perhaps the kid next 
> > door is the best 
> > example, or, even my own kids. Kids do not wear 
> > coats.....simple fact. 
> > I don't care what the temperature is outside, they 
> > do not wear 
> > coats....unless forced to do so. Do kids get sick 
> > every time they go 
> > out the door? Nope. Can they go out in hot weather 
> > without a coat and 
> > suffer no ill effects? Sure. How about warm 
> > weather? Absolutely. Ok, 
> > let's get to the cold weather level? Sure, they can 
> > play in cold 
> > weather without a coat and do fine too. Freezing 
> > weather? Yep, this 
> > works too. Seen it with my own eyes. Annnnnnnnnnd, 
> > I am sure if most 
> > of us think back to our childhoods (which for me is 
> > a bit of a 
> > challenge) we will remember times when we played 
> > outside in the cold 
> > without coats too and suffered no ill effects. The 
> > key is the amount of 
> > exposure to the outside temperature and health of 
> > the individual when 
> > temperature change occurs from what I have seen. 
> > 
> > For instance......kids playing outside in 40 F 
> > degree weather, without a 
> > coat, can go for hours with no significant impact, 
> > except rosy cheeks 
> > perhaps. Go to temperatures below freezing and now 
> > it is a matter of 
> > how long the extremities (fingers, toes and nose) 
> > can handle the cold 
> > before the initial effects (burning sensation) of 
> > frostbite set in. 
> > Yet, even when we begin to feel the first stages of 
> > frostbite it does 
> > not mean that one will become sick from it. It's 
> > amazing how well a 
> > person can adapt to temperature changes from about 
> > 25 F to 100+ F with 
> > no ill effects. 
> > 
> > Now, let's expose that same person to a cold or flu 
> > virus or bacteria 
> > and do the same thing. Seems that the person is 
> > more apt to becoming 
> > ill as a result. The temperature change is an added 
> > stress (your body 
> > will try to maintain its set temperature) on the 
> > body's system that 
> > makes it easier for the virus or bacteria to 
> > overwhelm the body's 
> > defense systems. The interesting part of this is, 
> > temperature change 
> > will not make you ill initially, but, it can lower 
> > your body's ability 
> > to defend itself against viruses or bacteria. 
> > 
> > Soooo, looking at this example, one would think that 
> > if fish are like us 
> > to some small extent they should be able to handle 
> > temperature changes. 
> > And, from my experience, they do. 
> > 
> > Ok, but, fish are not warm blooded(Endotherms, like 
> > us). Fish are cold 
> > blooded(ectotherms) Well, this is true. Yet, can 
> > cold blood and warm 
> > blood make that much of a difference in temperature 
> > tolerances? 
> > Warm-blooded creatures, like mammals and birds, try 
> > to keep the inside 
> > of their bodies at a constant temperature. They do 
> > this by generating 
> > their own heat when they are in a cooler 
> > environment, and by cooling 
> > themselves when they are in a hotter environment. To 
> > generate heat, 
> > warm-blooded animals convert the food that they eat 
> > into energy. 
> > Cold-blooded creatures take on the temperature of 
> > their surroundings. 
> > They are hot when their environment is hot and cold 
> > when their 
> > environment is cold. In hot environments, 
> > cold-blooded animals can have 
> > blood that is much warmer than warm-blooded animals. 
> > Cold-blooded 
> > animals are much more active in warm environments 
> > and are very sluggish 
> > in cold environments. This is because their muscle 
> > activity depends on 
> > chemical reactions which run quickly when it is hot 
> > and slowly when it 
> > is cold. A cold-blooded animal can convert much more 
> > of its food into 
> > body mass compared with a warm-blooded animal. 
> > 
> > What does this mean? Something interesting happens 
> > here. A 
> > disadvantage to being warm-blooded is that 
> > warm-blooded bodies provide a 
> > nice warm environment for viruses, bacteria and 
> > parasites to live in. 
> > Mammals and birds tend to have more problems with 
> > these infections than 
> > do reptiles and fish, whose constantly changing body 
> > temperatures make 
> > life more difficult for these invaders. However, an 
> > advantage of this is 
> > that mammals and birds have developed a stronger 
> > immune system than 
> > cold-blooded animals. 
> > 
> > A cold blooded reptile or fish immune system is more 
> > efficient when the 
> > animal is warmer. This can be seen when treating 
> > fish for ick. The 
> > first thing that helps is to elevate the tank 
> > temperature. This forces 
> > the bacteria to replicate faster, but, it also 
> > offers the fishes immune 
> > system a chance to go into high gear to fight 
> > infection too. However, 
> > since bacteria probably grow more slowly in lower 
> > temperatures, cold 
> > blooded animals sometimes intentionally lower their 
> > body temperatures 
> > when they have an infection. This is proven out in 
> > studies of disease 
> > control in axolotls. Diseased axolotls can be 
> > placed in a refrigerater 
> > and cooled to near freezing and they seem to heal 
> > quicker than if left 
> > at higher temperatures. So, you can see cold 
> > blooded animals walk a 
> > thin line as to which is better, cooler temperatures 
> > or warmer ones. 
> > 
> > The key to the fish and axolotl temperature impact 
> > is the duration of 
> > the temperature (Hmmmm, sounds like my kids again). 
> > Axolotls kept as 
> > near freezing do not eat. How long can they go 
> > without eating? Long 
> > enough to fight off an infection if they are in 
> > reasonable 
> > condition.....but, not for significantly long 
> > durations. How long can a 
> > fish go at elevated temperature? Long enough to 
> > allow ick medication to 
> > kill off the parasite, but, they cannot live at 
> > elevated temperatures 
> > near as long as they can at cooler temperatures. 
> > 
> > Ok Clay, what is the point of all this? In short, 
> > the health of the 
> > subject and duration of the temperature change are 
> > the keys to the 
> > potential adverse impact of environmental 
> > temperature variance to the 
> > subject. Temperature fluctuations over short 
> > periods of time (swimming 
> > through thermoclines) can be accommodated by fish 
> > with no adverse 
> > impact. This is only true provided the fish are 
> > healthy to begin with. 
> > If a fish is diseased, temperature fluctuations can 
> > either improve or 
> > degrade the subject's condition. Without trial and 
> > error, I am not sure 
> > if it can be predicted which way the diseased 
> > subject will sway when the 
> > 
> === message truncated === 
> 
> 
> 
> 
> __________________________________ 
> Yahoo! Messenger 
> Show us what our next emoticon should look like. Join the fun. 
> http://www.advision.webevents.yahoo.com/emoticontest 
> _______________________________________________ 
> GSAS-Member mailing list 
> GSAS-Member@thekrib.com 
> http://lists.thekrib.com/mailman/listinfo/gsas-member 
_______________________________________________
GSAS-Member mailing list
GSAS-Member@thekrib.com
http://lists.thekrib.com/mailman/listinfo/gsas-member