Male sharks and rays can pass sperm along a duct into a seminal vesicle, where they store it for a while before it is expelled, while teleosts usually employ separate sperm ducts.
From the en.wikipedia.org
Local testosterone causes each wolffian duct to develop into epididymis, vas deferens, and seminal vesicles.
From the en.wikipedia.org
Due to the blockage of ejaculatory ducts, enlarged seminal vesicles are frequently seen in patients with ejaculatory duct obstructions.
From the en.wikipedia.org
Males also have internal structures as well, and these consist of the testicles, the duct system, the prostate and seminal vesicles, and the Cowper's glands.
From the en.wikipedia.org
Next, androgens cause the development of the Wolffian duct system, which develops into the vas deferens, seminal vesicles, and ejaculatory ducts.