One of the sages, Rav Judah, said that G-d created male and female of all creatures, even the slant serpent leviathan and the tortuous serpent leviathan, very large animals. But if these large leviathans were to reproduce they would destroy the world, so G-d castrated the male and killed the female, salting her away for the righteous in the future. Thus, too, for the behemoth on a thousand hills — G-d created both male and female of the species, but if these large animals were to reproduce they would destroy the world and so G-d castrated the male and cooled the female’s sex drive. The scholars asked: Why did the Lord not cool the female leviathan’s sex drive as he did the female behemoth? Answer: Fish are sexually licentious and cooling the female’s sex drive would not stop them having sex, reproducing, and destroying the world. The students than asked: Why did G-d castrate the male leviathan and kill the female and not the other way around, killing and salting the male and sterilizing the female? Answer: Salted female leviathan is better than salted male leviathan. Another answer: G-d planned to sport with the male leviathan it would not be proper to leave the female with him as it would not be appropriate for G-d to sport with the male and female together. The scholars then asked: Why did G-d cool the ardors of the female behemoth instead of salting her as He did the female leviathan? Answer: Salted fish is prime, salted meat is not.
(Babylonian Talmud, Tractate Bava Batra 74b)