The koi fish are beautiful, are so pretty besides what they represent. Seeing a watercolor of yours is great, it looks very pretty besides that the colors have been very good, it's good that you've decided not to use the pencil, many times those strange lines are left heheh.
Great work.
I know that you can make a beautiful mermaid.
Thank you so much! :D I think I'll try @ryivhnn 's idea of doing less human looking mermaids ^-^
That can work. :)