noun
zoanthid
A type of colonial cnidarian resembling sea anemones, often found in sandy areas. The Japanese name literally means 'sand purse'.
スナギンチャクは砂地に生息するイソギンチャクの仲間です。
Zoanthids are relatives of sea anemones that live in sandy areas.
イソギンチャク (sea anemone) is a more general term; スナギンチャク specifically refers to zoanthids, which are often colonial and found in sand.
From 砂 (すな, 'sand') + 巾着 (きんちゃく, 'drawstring pouch'), referring to the sand-encrusted, purse-like appearance of the colony.