This organism features a unique, distinctly sized and spaced white spots across their three pereopods (walking legs) against a maroon shell.

[3] They typically have longer, slender, eye stalks, along with a less rounded carapace.

[4][5] Calcinus argus has the segmented head, thorax, and abdomen, of the phylum Arthropoda.

They are rarely found in the geographic division Indo-West Pacific;[2] in shallow waters ranging from Eastern Africa to the Hawaiian Islands.

[4] Calcinus argus can be found in intertidal depths from the surface to around 40m, enough exposure to moving, clean salt water, and never in the deeper waters, preferring the reef;[4] with the sea surface temperature in the 25-30 °C range, and sea surface salinity at 30-35 PSU.