These snails give live birth, and it’s the babies that may do the labor
Protecting eggs in mom’s body may have given periwinkle snails an advantage over egg-laying cousins
By Susan Milius
The oddball minority of animals that don’t lay eggs includes a tough little snail called a rough periwinkle.
Unlike mammals giving birth to kittens and fawns and helpless little humans, this tidal-zone snail has switched to live birth relatively recently. Its newcomer version of birthing offspring into the world without an eggshell is…. different: These periwinkle moms give birth multiple times a day. And unlike humans, it’s probably not the mom but the babies who do the hard labor.