Origin

The character 鯨 combines the fish radical 魚 on the left to signal "this is a type of aquatic animal" with the component 京 on the right, which serves as a sound hint suggesting the pronunciation. Since whales are large marine creatures, the character needed a way to distinguish them from ordinary fish, so a phonetic component was added to create a specific term. The fish radical makes clear we're talking about something from the sea, while the sound hint helps speakers remember and pronounce the character correctly.