When I got home, I sat in my chair, hit play on my record player, fed my
fish, watched them swim around.

I gave them some extra treats: freeze-dried bloodworms.

I spotted some new baby swordtails in the tank, hiding inside the
floating spiky foxtail plants.

Until I put the plants in the tank, the adults would eat the babies.

Once I watched a baby fish come out of the mother and then the mother
immediately turned around and ate it.

I asked the guy at the fish store if the mothers eat the babies because
something was wrong in the tank, like maybe there was some external
stressor, or bad nutrition, or something else.

He said that if I wanted the babies to survive, I'd need to put places
in the tank where only the babies could go.

I said that it didn't make any sense for mothers to eat their children.
Why make something  to destroy it?  There had to be something wrong
that I could fix maybe to stop the behavior.

He said he's been running the fish store for years and years and never
not seen swordtails eat their young.

So I got the foxtail plants and sure enough, the next time I saw babies
come out of a mother, the babies raced to get to safety.

Now I remember I even looked up at the library one time "swordtail
cannibalism" and found some academic articles about how to reduce it.

It's been observed in captivity and in the wild.  So maybe the mothers
aren't killing their babies as an act of mercy because life in my fish
tank is such unmitigated hell.

Some mothers are just really awful.