Ever more complex: a new type of organization of reproductive organs in female Dorippe sinica Chen, 1980 (Decapoda: Brachyura: Dorippidae)

In this study a new organization of the female reproductive organs of Eubrachyura is presented after using both histology and MRI and μCT analyses to investigate the morphology and function of the female reproductive organs of Dorippe sinica Chen, 1980. The reproductive organ is composed of two parts: an ectodermal sperm site and a mesodermal ovary. The ectodermal sperm storage site incorporates a concave vagina and a seminal receptacle, which is completely lined by cuticle and is not connected to the ovary. Additionally, a cavernous body is attached to the seminal receptacle. This cavernous body can be interpreted as an important feature in the fertilization process in relation to transporting the spermatozoa out of the lumen of the seminal receptacle. Independently of the seminal receptacle, the ovary is connected to the oviduct via a single opening. The oviduct is lined by an apocrine glandular epithelium. The oviduct and the vagina open directly into the vulva. These new discoveries are compared to the known pattern of eubrachyuran female reproductive systems.