How to Tell a Male From a Female Shark

How to Tell a Male From a Female Shark Ever wondered how to tell the sex of a shark? Distinguishing the sex of a shark is easier than in most marine species. Its all in the sharks external anatomy. Male sharks have modified pelvic fins called claspers. Females do not have these claspers. As male sharks age, the calcium is deposited in the claspers, so that older males have harder claspers. In addition to the absence of claspers, females tend to be larger than males, although those differences may not always be obvious, especially in the wild. Where Claspers Are Located These claspers are located on the sharks underside, within the sharks two pelvic fins. They look kind of like long fingers that extend underneath the sharks belly.   Shark Reproduction in Brief The claspers are used for reproduction. Sharks breed via sexual reproduction with internal fertilization. This involves the sharks usually positioning themselves belly to belly, a process that can involve a lot of biting. The claspers have grooves which are used to transfer sperm from the male shark to the females cloaca.  The sperm is moved through the grooves using seawater. The sperm fertilizes the females eggs, and voila!- a shark embryo is created. From there, development and birth vary by species.   In some species, such as bamboo sharks, the female lays eggs outside of her body (oviparous). About 40% of the 400 shark species lay eggs. In ovoviviparous  sharks, such as whale sharks, basking sharks, and thresher sharks, the eggs develop inside the females body, but the young are born live. Placental viviparous sharks give birth in a way similar to mammals- the young shark is nourished inside the female by a yolk-sac placenta, before being born live. Bull sharks, lemon sharks, and hammerhead sharks are examples of species that employ this strategy.