bullhead, rockfish, razor clam, flathead, (kokuji)
鮴 is a kokuji (Japan-made kanji) that names several unrelated aquatic creatures: bullhead, rockfish, razor clam, and flathead. There is no single conceptual center; it is a character assigned to these specific fish and shellfish names.
鮴 is a kokuji created in Japan by combining the fish radical 魚 with 休, likely chosen for its sound to represent the Japanese names of various aquatic animals. The exact historical reasoning is uncertain.
A fish 魚 resting 休 at the bottom of the sea—imagine a bullhead or rockfish hiding among rocks, or a razor clam buried in the sand.
For めばる, picture a fish resting on a meager bar of sand: meager bar -> めばる, and the fish is a rockfish or bullhead.
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