noun
Penepatella stellaeformis (species of limpet)
A species of limpet with a shell resembling an ivy leaf. Typically written in katakana as ツタノハガイ.
ツタノハガイは潮間帯の岩に付着している。
Penepatella stellaeformis attaches to rocks in the intertidal zone.
この貝はツタノハガイと呼ばれ、その名の通り蔦の葉のような形をしている。
This shellfish is called tsutanohagai, and as the name suggests, it is shaped like an ivy leaf.
From 蔦の葉 (tsuta no ha, 'ivy leaf') + 貝 (kai, 'shellfish'), referring to the ivy-leaf-shaped shell.