eli5 Does a frog have 4 stages or 3

Question

I’ve been told that a frog have a four stage life cycle but many tell me it’s 3. Can someone explain to me the three?

In: Earth Science

Answer 1

It kind of depends on how you count them.

1. There’s the frog of course.
2. When frogs mate, they lay eggs.
3. The eggs hatch into tadpoles, a larval state with gills, a tail and a lateral line
4. The tadpole will metamorphose into a froglet with legs and lungs
5. Some definitions define a tadpole with legs and a tail state and a froglet state that is basically a tiny frog with a tail before it loses the tail and becomes a frog properly.

The metamorphosis from a tadpole into froglet is gradual. I don’t think biologists are particularly concerned with how many steps there are.