Many researchers are trying to figure out processes that they cannot see, for example, reproduction. They want to know how sexual interactions take place between marine animals and how genitalia has evolved to suit their needs. And now a recent study has revealed that scientists have successfully obtained that first 3D C.T. scans of both male and female genitalia of Dolphin and have successfully figured out how those reproductive organs function especially during intercourse.
For the study, the researchers used the preserved genitalia from dead ones, and they wanted to know how the penises and Vaginas fit together. One of the lead researchers, Dara Orbach, had the vaginas of Dolphins ready. She knew that the marine mammal vaginas are far more complex than other species because they have lots of labyrinthine pockets, folds, and twists which help them control paternity. Also, unlike the fleshy human penises, the penises of whale and dolphin are a lot tougher and its very difficult to artificially inflate cetacean penis.
The Dolphins have a fibro-elastic penis that means their penile tissue contains a lot of collagen which makes the penis very stiff and less extensible, even when they are flaccid. But when she started dissecting more and more reproductive tracts, she realized that the vagina would have coevolved with the penis and wanted to understand how both the genitalia fit together during intercourse. For the study, the team collected the genitalia of sexually mature male and female harbor porpoises, bottlenose dolphins, short-beaked common dolphins, and harbor seals that had died of natural causes, and selected the best male and female specimens from each species for further study.
The penises were pumped full of saline to make them erect, and both the genitals were fixed in a formaldehyde solution so they would keep their shape, and the penises inserted into the vaginas and sewn into place. Then with the help of computed tomography, the researchers tried to figure out how the penis fits inside the vagina, how deeply it penetrates, and which structures inside come into contact. They concluded that the male and female genitalia might have closely co-evolved, but due to the complex structure of Vagina, the penis and the sperm need to navigate efficiently to successfully reach the fertilized egg. The research was published in the journal Proceedings of the Royal Society B.