sexually
Nearly all fish reproduce sexually, and most species have separate sexes. Those without separate sexes avoid self-fertilization by producing sperm and eggs at different times. Each fish typically produces a large number of gametes. In most fish species, fertilization takes place externally. These fish are oviparous . Eggs are laid and embryos develop outside the mothers body. In a minority of fish, including sharks, eggs develop inside the mothers body but without nourishment from the mother. These fish are ovoviviparous .