The morphological ontogeny of Ceratozetes shaldybinae Seniczak et al., 2016c is described and illustrated. The adult of this species has a long lamellar cusp and 10 pairs of notogastral setae or alveolar vestiges, and is similar to that of C. helenae (Pavlichenko, 1993), but differs from the latter mainly by larger porose area A1 and longer seta v" on femur II. However, these species differ more distinctly from one another in the juveniles. The larva of C. shaldybinae has a pygidial shield bearing setal pair dp, whereas C. helenae lacks this shield and setae dp are placed on individual sclerites. In the tritonymph of C. shaldybinae, setae of p- and ad-series are inserted on unsclerotized cuticle, whereas in C. helenae they are placed on microsclerites. The tritonymphs of both species have the same number of setae on the gastronotal shield (five pairs), but in C. shaldybinae setae dm and dp are thicker than in C. helenae. The juveniles of these species differ also by the shape of some setae on the body and legs.