This fluid contains nutrients for spermatozoa, oocytes, and zygotes. The oocytes are then combined with spermatozoa and fertilized. Fertilization of two different oocytes by two different spermatozoa results in fraternal twins. This increase in pregnancy rate occurs despite a lower value of total motile spermatozoa. The male gonad, the testicle, produces sperm in the form of spermatozoa. These develop into mature spermatozoa, also known as sperm cells. The male has two testes, which contain follicles in which the spermatozoa are produced. Testes produce 200 to 300 million spermatozoa daily. Sperm sorting utilizes the technique of flow cytometry to analyze and 'sort' spermatozoa. The resulting spermatozoa are now mature but lack motility. Conjugate pairs dissociate into separate spermatozoa before fertilization. A secretory gland nourishes the contained spermatozoa in the vagina. Deployed apical hooks combine with apical hooks and flagella of other spermatozoa. He was the first to show that fertilisation requires both spermatozoa and an ovum. Increased aneuploidy is often associated with increased DNA damage in spermatozoa.