carp
鯇 centers on the fish known as carp, a common freshwater fish.
鯇 combines 魚 (fish) with 完, which likely contributes the sound カン. The character specifically denotes a carp.
The left side 魚 means fish, and the right side 完 suggests completeness. Imagine a perfectly complete fish—a carp, often seen as a symbol of wholeness.
For カン, picture a can of carp: can -> カン, and the fish 魚 is inside the can.