When zebrafish eggs are laid, they are surrounded by a tough chorion. Sperm are unable to get through this chorion and must find
the tiny tunnel called a micropyle that provides a channel to the egg cell membrane. This channel is so tiny that only one sperm is able to fit through at a time. The micropyle most likely Aids in preventing polyspermy.
The polyspermy is a condition in which more than one sperm penetrate the nucleus of the mother egg. This process results in the contribution of extra centriole to the egg. The presence of the extra centriole the first division is affected and chromosomal partitioning hampers.
In the given situation, the tiny channel of micropyle can accept only one sperm to fuse with the egg membrane thus this will aid in preventing the polyspermy.
