carp
鯪 refers to a type of carp, a freshwater fish. The meaning is specific to this fish species.
鯪 combines 魚 (fish) with 夌, which likely contributes the sound. The exact historical origin of 夌 in this character is uncertain.
The left side 魚 means fish, and the right side 夌 looks like a fish with a tall dorsal fin. Picture a carp with a prominent fin: 鯪 is that carp.
For リョウ, imagine a carp leaping over a dragon gate and transforming into a 龍 (りゅう, dragon). The similar sound リョウ echoes the legendary carp's ambition.