When compared with M. mesembrinum, M. parva has
fewer pectoral-fin rays (10 vs. 14–15), more lateral-line scales (40–44 vs. 35–39) and a subsuperior (vs. terminal)
mouth. Fin-ray counts distinguish M. parva from M. lineata and M. bounthobi: anal-fin rays 12–14 (vs. 15–20),
pectoral-fin rays 10 (vs. 12–16) and pelvic-fin rays 6 (vs.7–8).