The penis of dasyurid marsupials

Our interest in the penis of dasyurid marsupials began with the observation by Woolley of an unusual appendage on the penis of one of the rarer species, the Dibbler, Antechinus apicalis . In the course of a study on the reproductive biology of the Dibbler (Woolley, 1971) two of the three males in the laboratory colony were seen with the penis everted. Figure 18.1 shows the everted penis of one of the Dibblers, with the appendage lying above the terminal, free portion of the penis. This part was flaccid and small by comparison with the appendage. Although it was not known whether or not the penis was fully erect, or the appearance normal, the male illustrated was able to copulate. This male had mated on four consecutive days with one female. The penis was first seen everted two days later. The following day he mated with another female and the penis, which remained everted after copulation, was photographed. Two days later the male copulated again with this female. A week after the last mating, the appendage was shrunken, which suggested that it might contain erectile tissue, but the entire penis was not fully retracted until three weeks later. The penis of a second male was seen when he was courting a female before copulating with her. The general appearance of the penis of this male was the same as that of the first but, in contrast, the penis was retracted immediately after copulation.