Hey, I used to have betta fish. Have you ever had one?
I have! I loved the ones that I had in my aquarium, because I was specifically looking for a freshwater ray-finned fish,and these were part of the gourami family, so they were very colorful. 
Oh cool. I didn't know they were from the gourami family. I think I remember something about them eating mosquito larva in rice paddies where theyre from.
Yeah, they're interesting little guys. They spawn in two different ways, either through bubble nests, like the B.Splendens, or through being a mouthbrooder, like the B.picta, if you want specific examples. They're quite unique!
Oh I only remember the bubble nest kind. I tried breeding mine once but I lost patience with it. I ordered some special leaves that released tannins  in the water. and the male built the bubble nest under the leaf.
Yeah, the mouthbrooding species, they're known as "pseudo bettas," because they're kind of considered to have evolved from the nest-builders in a sort of adaptation to their fast-moving stream habitats. Evolution is interesting!
Oh yeah that is different. I think the bubble nest kind are in more stagnant waters. Do the mouthbrooders have any other cool adaptations? 
Well, just in general, this type of fish has an ability to thrive in low-oxygen water conditions that would leave most other fish dead. These environments are places like rice paddies, slow-moving streams,drainage ditches, and even large puddles. They're very versatile.
They sure are. Evolution and nature are incredible. 
Absolutely. A 2004 phylogenetic study even concluded that bubble-nesting was the ancestral condition in "Betta" fish, and that the mouthbrooders mentioned earlier had evolved on multiple occasions throughout their genus. So, they just keep continuing to change.