This species is a large sized species of Priapella (maximum length 4.8 cm SL). It is distinguished from its congeners by having the following characters: a membranous hook of the gonopodium ray 3 well developed and semicircularly bent (vs. slightly bent in P. bonita, P. compressa, P. intermedia and P. olmecae); subdistal plate-like membranous process on gonopodium ray 3 well developed (vs. not prominent in P. compressa and P. intermedia); spines of gonopodium ray 3 long and not numerous (vs. numerous and densely crowded in P. compressa and P. intermedia) and short and not densely crowed in P. olmecae); distal part of gonopodium ray 4p slightly bent (vs. strongly bent in P. bonita, P. compressa, P. intermedia and P. olmecae). This species is also distinguished by having a short gonopodium; frequency distribution of SL/GL radius 3.30-3.50 (vs. 2.60-2.75 in P. olmecae, 3.00-3.20 in P. compressa, 2.60 in P. bonita and 3.50-3.60 in P. intermedia; gill rakers 10-12 (vs. 15-16 in P. bonita, 120-13 in P. compressa, 12-14 in P. compressa; dorsal-fin rays 9 (vs. 8 in P. bonita, 10 in P. compressa (Ref. 57748).