Plate 1 issued from : J.G. Greenwood in Proc. R. Soc. Qd, 1978, 89. [p.16, Fig.7, c, e, g, h]. As Acartia pacifica forma mertoni.
Female (from Moreton Bay, E Australia):c, posterior metasome and urosome (dorso-lateral); h, P5.
Nota: P5 with base of terminal spine gibbose and margins of spine finely denticulate (as in A. pacifica), but seta and spine of similar length (seta twice length of spine in A. pacifica.

Male: e, posterior metasome and urosome (dorso-lateral); g, P5.
Nota: 3rd urosomal segment with 2 larger spines dorsolaterally on posterior margin, row of 6-8 spinules between.

Plate 2 issued from : A. Steuer in Arb. zool. Inst. Innsbruck, 1923, 1 (5). [p.30, Figs.138-141]. As Acartia (Odontacartia) pacifica var. mertoni.
Female (from Aru Island): 138-139, last thoracic segment and urosome (dorasl); 140a, P5 (ventral); 140b, P5 (lateral).

Male: 139, last thoracic segment and urosome (dorsolateral); 141, P5.

Plate 3 Erratum: read Srinui and not Siruani.
Female:
1 - Genital double-somite having paired posterodorsal processes.
2 - 2nd segment of A1 without strong curved processes.
3 - Exopod of P5 not thickened proximally.
4 -, Caudal ramus longer than wide by ca 3 times; 2nd free urosomite lacking small dorsal spinules.

Male:
1 - Urosomite 3 with large spine-like processes dorsally.
2 - Dorsal processes of urosomite 3 long, reaching half-length of anal somite.
3 -, Urosomite 4 lacking spine-like processes between pair of dorsal processes.
4 - Genital somite with spinular rows along posterodorsal border.
5 - Inner projection of 1st exopodal segment of right P5 quadrate.

Plate 4 Issued from : S. Lee, H.Y. Soh & W. Lee in ZooKeys, 2019, 893. [p.84, Table 3]. Acartia (Odontacartia) mertoni: Morphological characters.
Compare with other Odontacartia species.

Nota:
1 - Absence of spine on 1st to 2nd segments of female A1 .....2.
2 - Spine present on dorsal surface of female genital double-somite ..... 3.
3 - Dorsal surface of female genital bouble-somite and 2nd urosomite with 2 strong spines .....4.
4 - Length of female P5 outer seta and terminal spine similar .......5.
5 - Female caudal rami is twice as long as wide.