Ezo neptune; Neptunea polycostata
A species of whelk found in northern Japan. The name is a biological term; in everyday contexts, it may simply be referred to as つぶ (whelk).
The Ezo neptune is a whelk commonly caught in Hokkaido.
A general term for whelks and similar edible sea snails. エゾボラ is a specific species within that category.
arthritic neptune; Neptunea arthritica
Katakana spelling is standard for this species name.
Kanji spelling; rarely used. The word is usually written in kana.
From 蝦夷 (Ezo, old name for Hokkaido) + 法螺 (conch/whelk). The exact derivation is straightforward; the kanji are rarely used in modern writing.