The case of the missing eggs

[tooth]

Last November when I noticed the second berried female in my tank, I counted about 10 to 12 eggs. As the weeks went by I saw fewer eggs. I didn't think much of it, as I had read about females dropping eggs. Not much one can do about it.
Just before the few remaining eggs hatched a few days ago, she was carrying only 3 eggs--I could easily count them.
No other females were/are berried. I only have 9 adults--easy to see/count them all.
But, I have 9 new larvae. Where did they come from? The previously berried female now has no eggs.
Do dropped eggs still hatch? When she first berried, I could see she struggled to keep the eggs contained in her swimmerettes. Do females drop, hide, and rotate eggs to keep them developing, when it is difficult to carry them all? I never saw eggs on the substrate. My substrate is almost completely covered with green algae. Red eggs would have been easily seen, if not hidden.
Anyone else have this experience?
Brad Hills
Alpine, Utah

[BostonJill]

That's funny I asked that question three days ago.

I have over a hundred shrimp in a five gallon tank so it would be impossible to tell what's going on but you have a controlled environment so my guess would be yes they can hatch if they fall. This is just my thoughts based on what you said but I really don't have a clue. Maybe if it's closer to the hatch date when they drop off their chance of surviving might be higher. I hope other people chime in. I also wonder if the snails would eat the eggs? I don't have any in my tank but I know lots of shrimp owners do.

[tooth]

That's funny I asked that question three days ago.

I have over a hundred shrimp in a five gallon tank so it would be impossible to tell what's going on but you have a controlled environment so my guess would be yes they can hatch if they fall. This is just my thoughts based on what you said but I really don't have a clue. Maybe if it's closer to the hatch date when they drop off their chance of surviving might be higher. I hope other people chime in. I also wonder if the snails would eat the eggs? I don't have any in my tank but I know lots of shrimp owners do.

Sorry I missed your post. I did not check any posts this week before I posted mine. I should have just added to your thread. Hopefully, Mustafa will chime in with some answers.

[Mustafa]

Since your questions are so similar, I'll provide my answer to both right here (as there is more of a background to the story in this thread). I know from my own observations that there is a high likelihood that Supershrimp eggs hatch in batches. I have observed the same thing in freshwater Amano shrimp. I don't think, however, that this kind of batch hatching would take weeks (although I can't rule it out without further observation). So, there may be a distinct possibility that eggs do hatch after being dropped. This would make sense in a way since these guys carry very few eggs and every eggs is valuable. They could have evolutionarily developed in a way that their eggs are really "tough", both in consistency and ability to fend off organisms (fungi, yeasts, bacteria etc.). That would be a huge advantage when it comes to maximizing reproduction rates.
(It's also interesting to note that Supershrimp females do not seem to "tend" to their eggs as much, or maybe not at all, as freshwater shrimp..i.e. I barely ever, if ever see them "aerate" the eggs with their pleopods (swimmerets). That may be a testament to the "toughness" of the eggs.)

On the other hand I have also had experiences where larvae just popped out of seeming "nowhere" in addition to experiences where fully formed young popped out of "nowhere." At the same time I know that in my tanks where there are still non-functioning sponge filters (i.e. they are in there because I've been too lazy, but they are not being used) from years ago, there are always berried females deep inside the sponge filters (in addition to other shrimp that keep them company ). So, if you make deductions from all of these observations, it would appear to be the case that some females are just so good at hiding that you never see them berried, whereas others run around and graze right there in the open.

So..although anything is possible, I'm going to invoke "Occam's razor" and go, for now, until further observations/experiments prove otherwise, with the theory that hidden berried females are responsible for mysterious appearances of larvae and young.

[tooth]

Only one thought to add: I have just 9 adults in the tank. They are all visible simultaneously a couple of times a day. There was only one adult berried female visible for the last 2 months. The only other source of eggs would have been the young shrimp from last October. Can they breed that young?

[Mustafa]

That's a very good question. We'll have to keep observing...maybe some eggs do develop *much* faster than others...

[tooth]

OK. The third berried female is now carrying fewer eggs than she was at first. Initially she appeared to have about 10 or so. Now she has about 5 or 6--hard to count. She is the only berried female in the tank. I can see all the adults in the tank simultaneously. So, unless one of the juveniles of about 4 months age is capable of reproducing, and is hiding from me, I have just the one berried shrimp. The newest shrimp are barely swimming at this point, not likely to reproduce.
The second berried female from last winter did the same thing. She appeared to drop some eggs toward the end, carrying only 4 (I counted), but then 9 larvae appeared within 2 days of each other. Which made me wonder if she was hiding some eggs, and 'switching' them out periodically. Or, if 'dropped' eggs still hatch from where they are resting.
Anyway, I cannot see any eggs on the substrate, but not all areas are visible. We'll see what happens this time.

[KenCotigirl]

Tooth any chance of pictures? Even poor ones can help. Another question. How many days between her dropping eggs till you saw floaters.? I have seen moms release larvae over several days. Larvae can be difficult to see at times. I am not questioning your observations. I just find it hard to believe dropped eggs hatch viable larvae. I would like to be shown i am wrong.

[tooth]

When the second female dropped eggs, I didn't think anything about it except 'oh well', so I didn't count the days. I would guess about 2 weeks before hatching I noticed she was carrying fewer eggs. Very unscientific, but I was not thinking about the possibility of something odd happening.
I wouldn't think that dropped (abandoned?) eggs would hatch, either. What do you think about the switching out idea?
I just got a good look at the current berried female. I counted 9 eggs. When I looked last night, there appeared to be fewer. Maybe she was carrying them differently, and I didn't have as good of viewing angles. It appears this female has not dropped any eggs at this time.
I'll keep watching and counting.
If I can get the camera to work, and the female to pose, I'll post a pic.