handmade pottery fish shape covered dish, rustic rough clay w/ celadon green glaze

I have no idea as to the exact age or origins of this fish shaped covered dish, but I love handmade pottery, and this piece looks special, with the celadon green glaze against the raw clay. It's not marked or signed that I could find.

Its about 11" long end to end, sized to hold an actual fish, so perhaps it's a baking dish? It doesn't look as though it was ever used, it's very clean and in very good condition.