6 replies to this topic

[Aquarist Fist]

Apologies for starting two threads in short succession (I'll open a third as soon as I have read more on sticklebacks  ), but I haven't found any definite info on this question. Maybe with the exception of the southern tip of Florida and maybe some particular biotopes, all native fish experience a temporary decrease in temperature in the winter months. If I have an indoor aquarium with temperatures anywhere from say 70 to 75, would that be acceptable year round without any negative effects on the fish (sunfish in this case)?

 

I am in NW Oregon, so we have very mild winters. What I could do is move the fish on the unheated porch for a few weeks from, say November till late December and then move them back in. Would there be any benefits to that? And would the benefits be worth the stress associated with relocating the fish?

[Dustin]

There are no real detrimental effects associated with keeping the fish at a constant temp.  The need for wintering has to do with spawning the fish.  Some fish require a wintering period in order to come into spawning condition.  Search for the user name Ken.  He has perfected the overwintering routine and spawning of darters using this technique.

[littlen]

To add on to what Dustin said, I haven't seen the need for many sunfish to start spawning by means of a cool-down period.  Usually changing the photo period (which can occur naturally if there is decent ambient light) is enough to trigger them.  

Agreed that there will not be any detrimental effects at a constant temp.  70-75 is great.  Sunfish are tough, and even if you wanted to cool them off by moving them outside there would be very little stress associated with the move.  So long as the move is done properly.  (Acclimating, similar water parameters, etc).

 

[creekcrawler]

I've brought mine tank down to 45 degrees in winter (big chiller).

The one time I had sunfish, they became very dormant in the colder water.

[zooxanthellae]

I know this has already been thoroughly answered, but if you were really interested in this, I'd recommend reading up on the hypothalamic–pituitary–gonadal axis for the species of fish you are keeping (easier said than done depending on the species). Different fishes have different spawning triggers. Goldfish, if I remember correctly, are a strict temperature dependent species where an increase from < 72 to >72 will trigger reproduction. Other species require a change in the photoperiod as littlen mentioned, or some combination thereof. I really don't know if there are any side effects to denying your fish this cycle, maybe greater somatic growth? 

[Aquarist Fist]

Right. I'm familiar with some of those triggers from keeping tropical fish (changing temperature and ph/hardness, simulating rain, etc.). I definitely don't want to breed my fish. I just want to make sure they are happy and healthy.

Edited by Aquarist Fist, 08 November 2015 - 03:00 PM.

[Matt DeLaVega]

I have nothing to back this up, but I imagine that not having a winter period probably shortens the life of fish slightly.