How to Tell a Baby Shark's Gender

When a baby shark emerges into the world, it is fully able and expected to care for itself and will have no further interaction with its mother. Some female sharks lay eggs that will hatch outside of the body (oviparous), while others hatch inside the body (ovoviviparous), in which case the shark births the live young into the sea. Still others give birth to live young (viviparous). Surprisingly, it is not necessary for a male shark to fertilize the eggs. In the absence of males, female sharks may still have female babies in a process called "parthenogenesis." Sharks are either genetically male or female from birth.

Instructions

    • 1

      Look underneath the shark and observe the pelvic fins, which are on the underside of the shark's body between the stomach and the tail, not as far back toward the tail as the anal fins. On the inside of the pelvic fins, if the shark is male, you'll see two small protrusions of cartilage that look like fingers. These are called "claspers," and they are inserted into the female "cloaca." On females, the inside of the pelvic fins are smooth.

    • 2

      If you must pick the shark up to look for claspers, hold the shark firmly, with one hand between the dorsal fins (on top of the shark's body) and the tail, and the other hand holding its body just above its pectoral fins (the side fins just below the gills). Even small sharks are very strong, and all sharks are born with a mouth full of teeth. Certain bottom-dwelling sharks, such as nurse sharks and angel sharks, have a buccal muscle, which allows them to pull oxygen off their gills for up to half an hour out of the water, as long as they are kept moist. Not all sharks have a buccal muscle, however, so do not take them out of the water for more than a few seconds.

    • 3

      If the shark is very young and small, it may be difficult or impossible to see the underdeveloped claspers. In this case, killing or dissecting the animal to look for its internal organs--the ovaries in the female, or the internal testes of the male--is the only way to determine gender.