Astropecten scoparius occurs in the East China Sea and around the islands of Hokkaido, Honshu and Kyushu.

[1] Astropecten scoparius is a predator and is found on the seabed in shallow water or buried in soft sediments.

Astropecten scoparius feeds largely on molluscs such as the clam Alvenius ojianus and the small gastropod Voorwindia paludinoides while Luidia quinaria is adept at catching brittle stars (Ophiura kinbergi) and other echinoderms.

Both have been associated with cases of paralytic shellfish poisoning of humans in Japan caused by consumption of the trumpet shell Charonia lampas.

[5] The starfish may themselves have incorporated TTX into their tissues through feeding on certain tiny gastropod molluscs Umborium suturale.