[2]: 49 The species was first formally described by Wilhelm Hess in 1865, named Penaeus plebejus (type locality Sydney).[3]: (p.

In 1997, Pérez Farfante & Kensley promoted the six subgenera to genus level, an approach that was subsequently followed by some authors but not others.

[6] Based on molecular sequences of ribosomal and nuclear genes, Ma, Chan, and Chu (2011) found that Melicertus with Marsupenaeus formed a clade separate from the other (sub)genera of Penaeus sensu lato.

However, due to the lack of morphological features that distinguish the clades (synapomorphies), they argued against creating two or three[b] genera, and proposed restoring all the species into a single large Penaeus genus.

[6] As at 2022, the name Penaeus plebejus is treated as "accepted" by checklists such as the World Register of Marine Species.

[7][8] However, Melicertus plebejus is common in recent scientific literature, so when seeking information it is necessary to search for both names.

[11] Uncooked, they are light coral pink, with fine dark reddish-brown lines along the crests of the rostrum, carapace, and 5th to 7th tail segments.

[9][c] Hexham Swamp on the Hunter River is considered by fishermen to have previously been a major nursery for eastern king prawns.