Re: Giant Whale ashore at Karachi
Some shark species are oviparous, meaning they lay eggs. Others are viviparous and give birth to live young. Within these live-bearing species, some have a placenta like human babies do, and others do not. In those cases, the shark embryos get their nutrition from a yolk sac or unfertilized egg capsules filled with yolk. In the sandtiger shark, things are pretty competitive. The two largest embryos consume the other embryos of the litter! All sharks reproduce using internal fertilization, though, with the male shark using his “claspers” to grasp the female and then he releases sperm, which fertilize the female’s oocytes. The fertilized ova are packaged in an egg case and then eggs are laid or the egg develops in the uterus.