Elasmobranchs have developed many reproductive adaptations over their million years of existence. Sharks can display different modes of reproduction impacting the microanatomy of female genital ducts, modified to carry embryos with or without placenta or lay eggs. The aim of this study is to determine if such specific adaptations to the reproductive mode can also be found in males. It is hypothesized that no major differences will be observed, as the male reproductive system has the main function to produce sperm. The subjects of this study were the aplacentally viviparous spiny dogfish (Squalus acanthias), the oviparous blackmouth catshark (Galeus melastomus) and the placentally viviparous milk shark (Rhizoprionodon acutus). The two first species were caught during an opportunistic survey in the Celtic sea, while the last one was sampled off the coast of Oman. The tissues were processed following histological and histochemical techniques. Microscopic observations of reproductive tract cross sections didn’t show major dissimilarities between these three species. From these results, it can be concluded that the male genital ducts of sharks do not present any particular adaptation to their reproductive mode, they all ensure the production and delivery of sperm to the female in the same way.
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