Egg retention

[TJ]

Anybody have any information on the dangers of egg retention in newts? I was under the impression that eggs not laid are absorbed without any harm to the female, but i heard from my vet that egg retention can be fatal, and indeed it's one reason why males tend to live longer in captivity than females (though the opposite seems to be the case in the wild).

I have some very gravid C.ensicauda and C.pyrrhogaster that I am worried about and am just not trying to accommodate by adding more plants and plastic strips for egg deposition.

 

[joseph]

hmmm...I've heard in fish that the females will become "eggbound" especially in hard water. The eggs are said to actually calcify inside them...and require things like gentle pressure to remove them before the female can breed again. I know of one guy who lost some livebearers due to(so he believes) to rich food causing them to produce too many eggs for there size and thus "burst".

 

[edward]

Hi Tim,
In reptiles and birds, excess calcium can be deposited on the eggs, however this is not the case in amphibians. At least in anurans, retained eggs can form adhesions to the body wall preventing passage from the body. This disruption can lead to complications resulting in the death of the animal (this is how it was explained to me).
That said, in my experience the female caudates do not appear to reabsorb the eggs as long as the conditions stimulating ovulation are present. Once the conditions disappear, the females appear to reabsorb the eggs (based on observations in A. opacum, A. maculatum, D. monticola, D. quadromaculatus, P. walt, C. cyanureus, N. v. lousianensis, and P. axantha). I had a female D. monticola that you could observe yolked eggs through the body wall for more than seven years.

Joseph, I would be surprised if the egg bound fish had them calcify as the the mechanism for this is not really present like in reptiles and a birds. I would expect them to form adhesions like in anurans (but this is an expectation I would have to go digging for info to confirm it).

Ed

 

[joseph]

Ed: I only have one source so far to confirm it(though this source probably cited from another source and so on) and it has become "general aquarium lore". So whether or not the eggs are truly calcifying is unknown to me. Since I always give fish a chance to get rid of eggs(and if I don't want the fry they make some of the best food items around) I havent experience these problems.

 

[edward]

Hi Joseph,
I have read anecdotal reports of overweight female fish that were eggbound rupturing and dying from the subsequent perotinitus.

After some thought I became curious if you know the what the source of food was for the original fish was? Some of the commercial fish foods are contain high amounts of vitamin D3 and it is possible that the eggs were calcified due to hypervitaminosis (as one possible scenario).

Just some thoughts,
Ed