Malaysian trumpet snails...Can they reproduce on their own?

Yes, some species of snails can reproduce on their own, the Malaysian Trumpet Snail being one of them. Their reproductive system is a bit interesting - contrary to popular myth, they actually have separate es (meaning both males and females exist) and can mate together and reproduce "normally", but females can also reproduce aually without a male. In the latter case, the babies will all be female, so as you can imagine, male Trumpet Snails are quite rare.