Andropodium

The andropodium ( ancient Greek ἀνδρός andros , German 'man' and ποδός podos 'foot') is an anal fin of the highland carp (Goodeinae) and half-billed pike (Hemiramphidae) that has been transformed into a mating organ . It is comparable to the gonopodium of the livebearer toothcarps (Poeciliinae).

During copulation, it is introduced into the genital opening of the female, via which the sperm reaches the eggs that are still in the ovary , where they are then fertilized. With this organ the fertilization of the germ cells in the body of the female and thus live birth is possible.