Female Shrubsea evolve into Kahula when exposed to a Water Stone. Male Shrubsea are not known to evolve into or from any other Pokémon.
Shrubsea shoot water from their mouths when threatened by opponents, and also do this to help them move through the sea. Their petals help it perform a powerful petal dance, and when the sun is out, their special attack rises sharply while cutting their own HP in 1/8s. They can sing beautiful lullabies to send Pokémon to sleep.
Shrubsea, like most other Grass types, have a gentle nature in general. They cannot swim on their own so drift along the sea, with only the current deciding where they go, unless they propell from the water using a powerful water gun attack. Shrubsea are born in the ocean, and its their job to get back to the shore to live for the rest of their living lives.
Shrubsea drift along the water, with only their flowers showing. They cannot swim on their own, so the ocean current decides exactly where they go. Most of the time, they live on beaches they have washed up on.
Shrubsea live on beaches and in the ocean. They cannot swim on their own so they just drift with the ocean currents.