especially since their native waters aren't that far from the sea (If I remember correctly they are both from New Guinea).
They are also pretty nifty little snail eaters - I just watched one of my females (with a very full belly) rip a baby assassin snail out of its shell by shaking it like a dog with a chew toy.
I had just fed them - so I think it might be more about keeping snails away from the breeding area rather than pure predation, although I'm surprised it was the female since the male guards the eggs...
Its too bad I had put them in my main assassin snail breeding tank
ooops