sea bass
鱸 refers specifically to the sea bass, a type of fish. The meaning is narrow and concrete, with no broader conceptual extensions.
鱸 combines 魚 (fish) with 盧, which likely contributes the sound ロ. The character was created to name the sea bass specifically.
The left side 魚 means fish, and the right side 盧 looks like a complex net or trap. Picture a sea bass caught in a fisherman's net: 鱸 is the sea bass.
For ロ, imagine a sea bass leaping out of the water and making a low 'ro' sound as it splashes back: ro -> ロ.