sentences:  Studies of females have found no traces of sperm inside their reproductive tracts, which suggests that fertilization occurs immediately following copulation, which may also trigger ovulation.The reproductive cycles of Portuguese dogfish in the Atlantic and Pacific are generally similar; sharks off Japan tend to produce larger numbers of smaller oocytes than elsewhere, while sharks off the British Isles exhibit a larger litter size and birth size (but smaller oocytes) than those off Portugal.There is a record of a hermaphroditic specimen with an ovary on its right side and a testis on its left.