Question: Can Breeding Successfully Occur In The Dark?

[sde]

Hi all,

So I am wondering if it is possible for breeding to successfully occur in the dark, I mean total darkness.

So basically I am wondering how a female can successfully pick up the male sperm packet in total darkness?

Thanks! -Seth

 

[Mark]

Courtship does take place in the dark because I've seen it myself. Remember these are nocturnal animals so your pitch black is probably very different to them. Also, for newts most courtship follows very strict rules of engagement using body positioning, visual cues and pheromones. It's not like the male is blindly depositing sperm in the hope that the female will find it, although that's a strategy adopted by some migratory salamanders.

 

[sde]

Courtship does take place in the dark because I've seen it myself. Remember these are nocturnal animals so your pitch black is probably very different to them. Also, for newts most courtship follows very strict rules of engagement using body positioning, visual cues and pheromones. It's not like the male is blindly depositing sperm in the hope that the female will find it, although that's a strategy adopted by some migratory salamanders.

My newts are T. granulosa so its pretty simple. The male just grabs the female and goes into amplexus and rubs his ( pheromones? ) all over her nose and strokes her with his back feet.
Then, as far as I know, just dismounts and drops a sperm packet, and directs her to it. That's the part I was confused about. How he and she know where exactly it is. Thank you for explaining!

-Seth

 

[frogman]

What I have seen with newts int he past is the male will get her attention and then drag his cloaca across the ground in which the female will follow to the spermataphore. I assume he is leaving a trail of pheromones that she picks up and follows. This is in triturus species though, I am not as familiar with the T. Granulosa spermataphore transfer

 

[Azhael]

Males don´t actually see the spermatophore once they´ve laid it so the guiding of the female into position is done entirely automatically. If you have the chance to witness several of these events you can see that the male always stops at the same point where the female´s cloaca would be placed directly over the spermatophore even if the female has already fled the scene. It doesn´t matter for the male if it´s pitch black, he never sees the spermatophore either way, it´s all instinctual.

 

[Chinadog]

I once read that the white flash that male Triturus newts develop in the breeding season is for visibility to females in low light levels?

 

[Azhael]

Hmmm...that´s an interesting thought but i´m not convinced. For starters not all species who share the deposition/pick up ritual have those and the ones who do, like Triturus, invariably have courtships in which the flashy strip is somehow involved (typically with lateral courtship which displays the strip).
Also, during the actual stage when the male is guiding the female the tail is curled up in such a way that the flashy strip is not in full display but mostly hidden by the undulatory movement of the tail, so even though it is visible, it kind of seems like it is badly exploited if that was its purpose.
Of course it could be the case that it is just one of its functions rather than the single purpose it is meant for, but regardless species who don´t posses such strips do very well without them with or without light.

 

[Chinadog]

I'm not sure myself, it was something i learned at school! It is true though, that no male newts that use amplexus have a tail stripe, or even have much of a colour change in the breeding season, though. Whereas many that have a courtship "dance" do get some kind of high visibility highlight on their tail?