This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
鰖 combines the fish radical 魚 with a phonetic component that likely contributed the reading タ. The exact historical development is uncertain.
The fish radical 魚 suggests a connection to fish, but the overall meaning is obscure. Picture a rare, unknown fish that scholars are still trying to identify.
For タ, imagine a fish so rare it's simply called 'ta'—a short, mysterious name that matches the reading タ.
Labracoglossa argentiventris (species of knifefish)