Create an underwater painting of a fantastical mermaid city, with shimmering coral castles, bioluminescent sea creatures, and mermaids gracefully swimming amidst colorful schools of fish. Let your imagination run wild as you bring this underwater wonderland to life on canvas.

Create an image of a fantastical underwater city populated by mermaids. The architecture consists of shimmering coral castles that glow with various hues under the water's surface. Include diverse mermaids, of varying races and genders, who are gracefully swimming amidst vibrant and colorful schools of fish. Bioluminescent sea creatures, each more enigmatic and radiant than the last, add an element of awe and mysticism to the scene. From the smallest anemone to the largest whale, every creature and structure contributes to the vibrancy and vitality of this underwater wonderland, skillfully depicted on canvas.