temperature/size

[Steven Gielis]

Everybody knows that the temperature affects the metabolism of spider. Buth what I ask myself: Does the raising temperature has any influence on the ultimate size of the spiders?

 

[spinnekop]

Everybody knows that the temperature affects the metabolism of spider. Buth what I ask myself: Does the raising temperature has any influence on the ultimate size of the spiders?

Steven, out of my personal experience... if you keep your spiders at high temperature, it increases the development speed but not the size (they mature more rapidly). In addition, if you keep your spiders at a higher temperature then ideal for the specie then most of them will become male.
I discovered this phenomena with my T blondi and Holconia immanis.
I found out I have to keep my T blondi at low temperature (25 degrees max) if I want to have pairs. At constant temperatures of 28-30 degrees and lots of food they all turn into male !!! Same for my other spiders.
The size seems more dependant on the food supply (quality and quantity).

 

[Emanuele]

So, in your opinion, a specimen has not sex until maturity?
That sound really strange for me...
Normally it's not a rare thing before hatching of eggs, but after hatching they should have a given sex until the mature molt...
Anyway, I'm really curious, it's interesting if you noticed it.
Cheers
Ema

 

[NRF]

So, in your opinion, a specimen has not sex until maturity?
Normally it's not a rare thing before hatching of eggs, but after hatching they should have a given sex until the mature molt...
Ema

Do you mean that it is common among spiders that eggs are not sex determined already???

 

[MartinW]

Hi,
interesting observation and something we have thought about before too, although more in terms of the temperature that the eggs are incubated at, as a few times we have had up to 80% of spiderlings we have obtained from others turn into males.
Personally I believe sex determination is set during the egg stage as I have never seen any spiders "change sex" during development. Of course even using a microscope to sex the spiders from skins can fail on small specimens but once they have moulted a few times I can usually be 99.9% sure I have a female.
Might look into this a bit more with our next batch of Ancylometes. Perhaps keep 40 or so at 25C and another 40 at 30C and then look at the sex ratios.
Will report on it if we get anything interesting.

 

[Elytra and Antenna]

That's a cool question though I doubt there's any real info for spiders. If it does have any effect I would imagine high temps above 80F would reduce the ultimate size of the adult. Holometabolous insects (beetles) are known to grow to a larger ultimate size at lower temperatures because the higher temps speed up molting while the speed of feeding doesn't increase correspondingly.
- low temps meaning 70-75 versus high 85+ -

 

[Timmy]

I watched a show on animal planet and crocodile sex was determined INSIDE THE EGG and temperature variation had effects on the sex. I beleive higher temperatures made males.