Creseis acicula is a species of pteropod, a distant type of sea-slug.

[2] Creseis acicula's size varies from 0.5–3.3 cm (0.2–1.3 in).

It is described as a straight-needle pteropod, and has small wings at the top of its 'head'.

[3] The species has a cosmopolitan distribution throughout the Caribbean, the Atlantic and Pacific oceans, the Mediterranean Sea and South America.

[4] The species feeds on small organisms such as diatoms, phytoplankton, archaea and larger protists.