Why do frogs lay eggs in varying numbers?

   Generally speaking, frogs lay eggs in large numbers. However, this is not always the case. The number of eggs laid by a female frog depends on the way the eggs are fertilized, and an embryo is formed. It is this embryo that later develops into a baby frog or tadpole.

            Normally, the female lays her eggs in water, and the male frog sprays his cells over them. This is called external fertilization. A great number of eggs have to be laid for external fertilization, because many of the eggs may not get fertilized at all. However, in the case of some frog, the eggs are fertilized inside the female’s body. This increases the chance of fertilization actually taking place, and so, fewer eggs need to be produced.

            The number of eggs laid also reflects the amount of care that the parent frog gives. Those frogs that take more care of their young lay fewer eggs, as the babies have a greater chance of survival.

            Most frogs lay between 1000 to 2000 eggs at a time – the American toad lays 4000 to 8000 eggs in one clutch. On the other hand, the tailed frog lays only 28 to 50 eggs per clutch, while the Cuban frog lays only one egg at a time!