Meaning
すだれ貝 (すだれがい, Sudare-gai) is Venus clam, a Japanese food (water animals).
What is Venus clam?
Sudare-gai (esp. Paphia euglypta ) are Venus clams, the family Veneridae . Over 500 living species of them are known, most of which are edible, and many of which are exploited as food sources. すだれ refers to a blind or a shade, or rattan, which might make for a good mnemonic for this clam.