Macrophthalmus Japonicus

We can discriminate female and male by their celiped.

If 2 legs are same, it is female but the male is larger than one.

They have 2 antenna and eyestalk and rostrum between antenna and eye on the head.

They can walk forward and backward and sideways.

They communicate through their claw-waving to fight with other males or invites females to mate.

Laying egg river snail~

River snail lay 5~6 eggs in a time and then die leaving only shell and operculum.

The female river snail is sacrificed to her eggs in laying.

Apple snail take in air through siphon

Apple snail use siphon to take in air on surface water.

Apple snail vs river snail

River snails have 1 pair of tentacle and gill to breathe.

Apple snails have 2 pairs of tentacle and gill/lung combination respiratory system.

They are all gonochorism, not hermaphodite.

Female river snail was killed by her babies

You can discrimate which is dead or alive snail.

After laying egg, all female river snail are killed by her babies in their inner body.

Their babies eat them to breed.

River snail

River snail have 1 pair of tentacle. One of male snail's is a little bending at the top of right.
They are gonochorism, not hermaphodite.
After mating female snail lay eggs.

But, female have all but same size and straight tentacle.

After hatching in it, Female river snail made a sacrifaced to their eggs and then die.