How does the male swordtail's anal fin differ structurally from the female's?

Answer

Males possess a pointed, modified anal fin called a gonopodium.

A critical sexual distinction is the anal fin: males possess a pointed, modified fin called a gonopodium used for internal fertilization, while the female's anal fin is fan-shaped.

How does the male swordtail's anal fin differ structurally from the female's?
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