Busy bubbles

There are three bubble shell snails in my tank. They're doing their best to turn that into thirty. Or three hundred.

Lone bubble shell, Haminoea japonica. Belly view, through glass.

Two bubble shells. The one in back has been following the other's slime trail from the far side of the tank, and is about to catch up.

At last! And the two slipped under the sand together, to indulge in their favourite pastime.

These snails are hermaphroditic; at each mating, one takes on the male role, the other acts as the female. The next time round, they may switch. And both are capable of laying eggs.

Their second favourite pastime. Laying eggs.

The eggs are expelled through a genital pore just behind the head. Each yellow egg is encased in a tramsparent jelly capsule, that is just barely visible in these photos.

As she lays the eggs, she curls away, leaving a crescent shaped jelly mass glued to whatever surface she has chosen (in this case the front glass wall of the tank.)

I'd never seen a bubble snail's mouth before; it's usually completely shrouded by the head shield and the lower foot.

The eggs should hatch in about a month. Unfortunately for the bubble's plans of conquest, the infants don't survive in the tank. They're probably swept up by the pump within hours of hatching.