A morphometric study published in 2010 showed that shell characteristics of S. spirula vary with geography, but no subspecies or additional species were proposed.

[13] S. spirula is capable of emitting a green light from a photophore located at the tip of its mantle, between the ear-shaped fins.

[10] Evidently this seems as a counter-illumination strategy, as in situ observations have captured footage of animals in a vertical stance, with photophore pointing downward and head up.

[10] Most sources cite this species as tropical and they are observed to be plentiful in the subtropical seas around the Canary Islands.

[16] However, significant quantities of shells from dead spirula are washed ashore even in temperate regions, such as coasts of New Zealand.

Much of the organism's life history has not been observed; for instance, they are thought to spawn in winter in deeper water, yet no spawnlings have been directly seen.

[17] The species was observed for the first time in its natural habitat in 2020, when an ROV of the Schmidt Ocean Institute recorded it in the depths near the northern Great Barrier Reef.