The older that such fish become, the more mercury they may have absorbed. Anything that eats these fish within the food chain also consumes the higher level of mercury that the fish have accumulated. This process explains why predatory fish such as swordfish and sharks or birds like osprey and eagles have higher
The goal, then, when it comes to having a boy is to increase the likelihood that a Y chromosome sperm reaches the egg first. Many medical researchers believe that Y chromosome sperm are faster swimmers, but that X chromosome sperm have more endurance.
studies show that the sperm that produce female offspring aka girl babies swim more slowly than the sperm that produce male offspring but they are also hardier br br this means that boy sperm swim fast but die faster and girl sperm swim more slowly but last longer the shettles method says that to increase your chances of having a girl have sex 3 days before you ovulate and to have a boy have sex the day before you ovulate