type of sea bream
魴 centers on a specific type of sea bream, a fish known for its flat, mirror-like body. The meaning is narrow and concrete, referring to this particular fish.
魴 combines 魚 (fish) with 方, which likely contributes the sound. The character was created to name a specific fish, the sea bream.
The left side is a fish 魚, and the right side 方 looks like a square, mirror-like shape. Picture a flat, square-shaped sea bream: 魴 is that fish.
For ホウ, imagine a sea bream leaping out of the water with a loud 'ho!' sound: ho -> ホウ, and the fish is a 魴.