Temperatures and Breeding.

[jewett]

Now that my water temperatures in my tanks have been dropping in the colder weather, I have been anticipating seeing courtship/breeding behavior from some of my animals. However, I realized that I don't know if it is a drop in temperature itself that induces some species to begin breeding, or the temp drop followed by the temp increase after the colder weather has ended (after doing some searches on the forum I think it is the latter)? I do know that some species do not really even need a temperature change and will be induced by a shorter photo period - but again, is it the shorter photo period itself, or the shorter day length followed a time later by longer days?
I ask because my water temperatures have been about 5-8 degrees cooler (about 60-62F) over the past several weeks than they were during the spring and summer, and though I occasionally see some of the males tail fanning and in their breeding colors, and a couple females are pretty plump and have been for some time, I have yet to observe any serious/frequent courtship behavior. Last year (the first year I ever had newts breed) I had gone on vacation in the early fall and somehow the house sitter messed with the AC and the house was freezing - my tanks temps were in the low 50'sF for about a week while I was gone. So of course there was a temperature increase after I got home and turned the AC off. I had eggs and larvae before Christmas. But this year no vacations accompanied by crazy AC fluctuations and I don't know when to expect eggs. Anytime now, or later in the spring when my tanks get a few degrees warmer (again, I am thinking the latter but want verification)?
Thanks to all who read the rambling post and even more thanks to those you can offer advice and information!

Heather

 

[Jake]

I've noticed that most of mine don't normally breed when it is really cold. They usually do it, like you said, when the temperature begins to rise after the cool period. For example, I kept the window open in my basement for several weeks, but then closed it one night because it was too windy. During the time that the window was closed the temperature rose by about 10 degrees. A few days later (after the closed window day) one of my ribbed newts, and two axolotls had laid eggs. That leads me to believe you're right about that. Also, last year all of the axolotls started to breed when it had reached about 65 degrees after being 45-55 for over a month.

 

[Daniel]

That's an interesting question, Heather!
I am not sure if there is one clear answer for all amphibia - different species may court at different times (spring / fall) in their natural habitat. I am not even sure with my axolotl either - they definitely started to lay eggs when it got colder in my cellar since there was no rise in temperature since then (same photoperiod due to electrical lighting).
On the other hand sometimes you can encourage Axolotls to lay eggs by making a waterchange with cooler water (even in summer with the domestic forms) - in this case I would not know whether it's the "getting colder" or the "getting warmer again" thing.

 

[Azhael]

I´m not sure...but in the case of my Cynops orientalis i think one of the causes might be a short terrestrial period.
In the nature at least here....i´ve seen Lissotriton spawn at very cold temps, and you can find ready males when temps are still very close to freezing....

 

[Azhael]

To confirm a little bit more my suspicions today i put my cynops pair back in the water (had to take them with me for christmas, and kept them terrestrial because i had no cycled tank) and only 4 hours later the male is insanely tail fanning and is over-excited. If the female starts laying again ina few days i´m gonna take for granted it´s the terrestrial period what gets these two in the mood.

 

[Daniel]

If the female starts laying again ina few days i´m gonna take for granted it´s the terrestrial period what gets these two in the mood.

That might be quite interesting...at least for the caudates living partly terrestrial and partly aquatic . But it doesn't explain the courtship-behaviour of purely aquatic species like the Axolotl and I remember some reports of people keeping Neurergus aquatic...
Keep us updated if you find any eggs!

 

[Azhael]

Oh i was talking just about my pair of Cynops...of course i wasn´t generalizing. I know many species and obviously the fully aquatic ones too don´t need a terrestrial period at all. But i do think those species that have a terrestrial period in their natural life cycle are at least helped by the terrestrial break...specially since the terrestrial phase is often the cooler too.
Btw my female has shown laying behaviour but she hasn´t laid yet...anyway i have hope she will eventually.