snapping turtle, fresh-water turtle
鼈 centers on a specific kind of turtle: a snapping turtle or soft-shelled freshwater turtle. The meanings are tightly focused on this animal.
鼈 combines 敝 (likely phonetic) with 黽 (a pictograph of a frog or turtle), indicating a turtle-like creature. The exact historical development is uncertain, but the structure suggests a phono-semantic compound.
The top 敝 looks like a tattered cloth, and the bottom 黽 is a turtle. Imagine a snapping turtle hiding under a ragged cloth in a freshwater pond.
For ベツ, picture a snapping turtle biting a betta fish: betta -> ベツ. The turtle snaps at the betta, linking the sound to the meaning.
Chinese soft-shelled turtle (Pelodiscus sinensis); soft-shelled turtle (Trionychidae)
Lethocerus deyrollei (species of giant water bug)
article of tortoise shell; tortoiseshell work
amber (colour, color)
spider wasp; pompilid
common stinkhorn (Phallus impudicus)