Genital tract and oocytic pathway during spawning in Pecten maximum (Molluscs, Bivalvia)

Summary Genital gland-kidney-digestive gland tissues from the scallop Pecten maximus were fixed for histological study at the onset of spawning. Examination of serial sections of these tissues allowed for the determination of the oocytic pathway and the reconstruction of the genital tract. Results indicate that there are two oocytic collector ways in the genital gland of P. maximus which are independent of one another throughout most of the gonad. Depending on their localization in the gonad, the oocytes are evacuated from the acini into the surrounding seawater environment via the gonoducts of one of these two oocytic ways. In the female gonad, each way is made up to two main oocytic collectors. In the male gonad there is only one collector for each way, and these collectors join up at their proximal extremity to form a short gonoduct that discharges all the oocytes into the right kidney. A portion of these oocytes is evacuated directly into the surrounding seawater via the urogenital orifice of this kid...