This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
鮩 combines 魚 (fish) with 并, which likely contributes a phonetic element. The exact historical development is uncertain.
The left side is a fish 魚, and the right side 并 looks like a net or trap. Imagine a fish caught in a net, but its exact meaning remains unclear.
For ホウ, picture a fish 魚 being thrown into a net 并 with a loud 'hoe!' sound: hoe -> ホウ, as the fish is scooped up.