She will make this process difficult by continually swimming away and even hiding from him. When the male gets close enough, he will rapidly insert his gonopodium (anal fin) into her anal vent. A tube ...

All right, I made up that last one, but there genuinely is a male Thai priapium that has his copulatory organ beneath his throat (plus ‘a fully functional testicle’) and the member (or gonopodium) of ...