Fertilization and Yolking in D. Fuscus

[john]

Actually, this question is probably much more generic than my subject line reads. I have a D. Fuscus female that appears to have some clearly yolked eggs. I collected this specimen about 2 months ago with no signs of any eggs at that time. She is currently kept with another fuscus that is presumed to be a juvenile and a D. Monticola. All of my research indicates a breeding season for this area in the May/June time frame. My question is, does yolking only occur post fertilization? I would assume so but the more i thought about it the more i realized i had no clue. I'm basically trying to determine if there is any probability that these eggs could actually be fertile, the female having mated prior to collection. I have a few pictures i will post.

 

[edward]

Yolking can occur seperate from breeding and fertilization. Also as I understand it Desmogs can retain sperm for a significant period of time (maybe Nate will want to chime in here also).


Ed

 

[nate]

It's been my experience with all Plethodontids that females will yolk every year if well-fed even if a male is not present. She'll either reabsorb them or lay the infertile eggs.

Ed, never heard the sperm retention with Desmognathus so I can't really chime in there.

 

[john]

Thanks for the info guys. I'll update if she lays and i see any development. But for now, i'm going to assume the eggs are infertile.

 

[john]

I would guess that each egg measures around 3mm diameter at this point based upon the best views i can get of them.

Another thing of note, some research i've done today indicates that D. Monticola ranges end up about two counties short of where we collected that specimen. A great deal of creme and blue-ish colored flecking on the sides along with lack of golden dorsal patterning is what led me to conclusion it was monticola. i'm very seriously doubting that at this point. Guess i need to get some pics of that one as well and see what some of you think. It is considerably more shy than the other 2 in the tank.

 

[john]

At long last, here are some of the pictures i've taken of her.

I still haven't taken any of the other adult tankmate. It stays well concealed and i don't really want to disturb too much by lifting up a lot of rocks

 

[john]

Just a quick update, she has reabsorbed these eggs. Based upon some recent field finds i realize she did not have the right type of substrate material to nest in. Next year, I guess...

 

[mark]

I'm not too familiar with the courtship rituals of D.fuscus but I think someone has been busy during the night. I can only think that this is a spent spermatophore? It was on a flat, wet stone out in the open. If it is one I'm guessing that the missing sperm packet is a good sign.