RE: NANFA-- Temps

Nick Zarlinga (njz_at_clevelandmetroparks.com)
Mon, 27 Oct 2003 13:12:41 -0500

Jeff, I would have to disagree with you somewhat. In my experience,
coldwater fish do better when you drop them to lower temps (if the temps
have to be changed). Conversly with tropicals. But of course, there are
limits.

I would agree that the key issue here is time. Todd, I have often wondered
about exactly the thing that you said about cool water "breezes" coming in
and the fish are now exposed to lower temps. But the thing that I think is
different (most of the time, but yes there are exceptions) is that it is not
totally changing the temp of the water permanently. What I have been
thinking about lately, is that unless you are a tuna, your body temperature
is the same as your surrounding water. If there is too drastic of a change
for a long period, the body temperature drops too rapidly, causing a stress
on the animal. This stress is different for different species. The one
that can handle it best are the ones that we generally refer to as "hardy".
Less hardy animals are then subjected to parasitic overload. In a stream,
the motile stages have a better chance of washing away, but in an aquarium,
they are continually swimming in the life cycle of the parasite, thereby
allowing for higher reinfection rates.

Ok, I am sure that my logic is way too simple for this problem. That would
mean that a larger fish (larger mass) should be able to take a short change
in water temp better than a smaller fish. I can't confirm or deny my
hypothesis, but in looking back on this email it sounds way too simple;)

My bottom line, keep the fish in the same temperature when transporting, or
*slowly* adjust the temp.

Nick Zarlinga
Aquarium Biologist
Cleveland Metroparks Zoo
216.661.6500 ext 4485

><)> -----Original Message-----
><)> From: owner-nanfa_at_aquaria.net
><)> On Behalf
><)> Of Jeffrey Fullerton
><)> Sent: Sunday, October 26, 2003 11:38 AM
><)> To: nanfa_at_aquaria.net
><)> Subject: Re: NANFA-- Temps
><)>
><)>
><)> Sudden temperature changes are not good for fish-
><)> but going from cooler
><)> water to warmer is probably less stressful than
><)> the opposite direction
><)> just the same as it is easier for humans to enter
><)> water that is warmer
><)> than the ambient air temperature as opposed to
><)> colder. It's also alot
><)> harder to get out once you are in!
><)>
><)> The thermal stability of water is far superior to
><)> air so that's why it's
><)> often alot more pleasant to go swimming or wading
><)> in the evening than at
><)> the start of the day.
><)>
><)> Jeff
><)> ---------------------------
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