Sphaerosyllis voluntariorum is a species belonging to the phylum Annelida, a group known as the segmented worms.
S. voluntariorum is more densely papillated on its anterior segments and has a long subdistal spine on the ventral simple chaetae.
This species' name alludes to the volunteers of the Marine Invertebrate section of The Australian Museum, who sorted specimens of syllids that led to the description of this animal.
The ventral simple chaetae on posterior parapodia are smooth, sigmoid and distally hooked, provided with a long subdistal spine.
[1] S. voluntariorum was found in Cape Range National Park, Western Australia, at a depth of 2 metres (6.6 ft) in mixed algae.