conger, sea eel
鱧 refers specifically to a conger eel or sea eel, a type of marine fish.
鱧 combines 魚 (fish) with 豊, which likely contributes the sound. The character was created to name this specific eel.
The left side is 魚 (fish), and the right side 豊 looks like a rich, abundant container. Imagine a plentiful catch of sea eels: 鱧 is the conger eel.
For レイ, picture a ray of sunlight hitting the sea eel: ray -> レイ, and the eel glistens in the light.
daggertooth pike conger (Muraenesox cinereus)
all men are alike; all lives are alike; all men live and die; we all bleed the same; a pike conger has one life, a shrimp does too