As the demand for seafood rises, nearly half of all seafood now comes from aquaculture. Why hasn't the amount of wild-caught fish caught
each year increased as well?

A major reason for the lack of any substitution effect with aquaculture, says Longo, is that many farmed species, such as salmon and bluefin tuna, are top predators so farming them requires feed made from other fish. ... “But it's hard to take a top marine predator and feed it soy meal,” Wiber says.

Explanation:

both male and female gametes are produced by meiosis of the germ cells. therefore, both male and female gametes are haploid. one male and one female gamete unite during the fertilization to form the diploid zygote. in seed bearing plants, pollen grain is the male gametophyte, which produces sperm cells.