Goby with eggs

Most fish species deposit eggs directly in the water and leave them immediately after spawning. The British ichthyologist Francis D. Ommanney commented on this breeding method: “Millions of unprotected eggs abandoned to their fate amid dangers of the ocean — what a wasteful way to continue the species.” However, some fish have “chosen” a new evolutionary way: they reduced the amount of eggs and started taking good care of them. The species having internal fertilization normally have the female take care of offspring, whereas species that make use of external fertilization put the male in charge of the new generation. Their care does not include the provision of food; therefore, a single parent is enough to protect eggs and young fish against predators and remove parasites.