Breeding Nerita

Has anyone successfully bred Nerite snails in captivity?

I have four individuals that I've collected at various times in water that was on the fresh side of brackish (SG measures an even 1.000 on my cheapo hydrometer, but I see brackish species with some regularity). They are wonderful for cleaning algae, interesting to watch and because of their heavy shells can be kept in tanks that otherwise cannot support snails due to heavy predation. I'd really like to have more of them, but they are hard to find and I'd prefer to breed them.

They lay eggs everywhere, but they never hatch in freshwater tanks. A couple months ago I set up a breeding project for them, consisting of a 5 gallon bucket with a sponge filter. I've since been feeding them sinking Spirulina wafers, and they've laid eggs all over the sides of the bucket and the filter. Over time I've raised the salinity with marine salt. SG is now at about 1.010, but I still see no evidence of hatches. I see a few egg cases that are open, and some that have changed from white to dark brown - not sure if that's a sign of a developing embryo or an unviable egg rotting - but I see nothing like a larva.

Anyone have advice on how to proceed?

I have had 10,000,000 hatch
and
have raised
none.

Breeding is easy, just like Welaka,
just recreate the native habitat,
which for nerites is an estuary.
Just change the salinity 2 times a day.

My water is a little hard and I add a little salt. I've had very few successfully reproduce in the past few years. I only collected them once and still have some from successful hatches of the original collection.

just recreate the native habitat,
which for nerites is an estuary.
Just change the salinity 2 times a day.

Do you have a reasonably easy method of doing this?

No,
And I should have said
Change the salinity 4 times a day.

Uland, can you provide any more details of the circumstances in which yours hatched? I think I'm 0 for 7000 now on even hatching an egg.

My understanding is that nerites have a planktonic larval form. I imagine that this would make them rather difficult to raise in aquaria. Is my understanding not correct?

That was my understanding too. Maybe not all species do that, but I have been looking for floating larvae also. I assume they'll be not too much smaller than the egg cases.

Uland, can you provide any more details of the circumstances in which yours hatched? I think I'm 0 for 7000 now on even hatching an egg.

I really wasn't trying. I had them in several tanks and one of my 55 gallon tanks with undergravel and large HOB filter with a salinity about 1/8 sea water had successful reproduction. Perhaps it was just a fluke but I'm certain they are Olive nerite.

That was my understanding too. Maybe not all species do that, but I have been looking for floating larvae also. I assume they'll be not too much smaller than the egg cases.

Take a good look at the egg cases; most hold over 100 veligers.

I have used a razorblade to open an egg-case that has changed to a brown hue
and have seen the veligers spinning around with my 25x pocket microscope.