Final answer:
The Cupid at Augustus' feet in the Prima Porta statue symbolizes victory and the emperor's divine ancestry, with the Cupid on a dolphin underscoring Augustus' connection to the gods, particularly Venus, from whom he claimed descent.
Step-by-step explanation:
The Prima Porta statue of Augustus is not just a simple portrait; it is rich with symbolism and political propaganda. The statue portrays Augustus as a youthful and idealized military victor and orator, invoking both the power of the Roman Empire and the emperor's divine lineage. Notably, at Augustus' feet, a Cupid on a dolphin is depicted, which carries important symbolic meaning. In this context, the dolphin symbolizes Augustus' victory in the naval Battle of Actium, which secured his position as the sole ruler of Rome. Cupid, known in Roman mythology as the son of Venus, emphasizes Augustus' claimed descent from the gods, as Julius Caesar, Augustus' adoptive father, asserted lineage from Venus.
Therefore, the presence of Cupid riding a dolphin at the feet of Octavian (Augustus) in the Prima Porta statue serves as a sign of victory and a representation of the emperor's divine ancestry and connection to the gods. This goes beyond the other interpretations such as a symbol of love and peace, representation of fertility, or representation of Mars, aligning with the narrative that Augustus was descended from Venus, thus strengthening his authority and legitimacy as emperor.