Tadpole Life Cycle

Tadpoles are amazing little creatures. They start out as eggs, floating free in the water. They turn into little swimming creatures that breathe water with gills. Then their bodies change and grow lungs - now they breathe air! These amphibians get the best of all worlds as they move from water-only life to being able to hop around on land.

Tadpoles and frogs are intensely studied in biology. As a result, their life cycle has been broken down into distinct phases so researchers can all discuss their findings in meaningful ways. This was done back in 1960 by K. A. Gosner. Scientists today still use this system.

Tadpole Eggs

Embryo Stage
When tadpole eggs are first laid by the mom frog, they are simply little round circles of nutrient with the tiny tadpole growing in the center. Stage 1 of Gosner's scale is that very first egg, newly fertilized by the father frog's sperm. Stage 2 is the egg thinking about dividing into two cells, and stage 3 is when the egg now has two cells after its first division. Stage 4 is the egg having four cells. As you can imagine, all of these embryo stages are completely invisible to the average observer unless they have microscopes and patience. Even as we get to stage 18 and 19, where there are tiny muscles and a tiny heartbeat, most people would be hard pressed to see this at the pinpoint size of the embryo. So most people only start attempting to watch their tadpole progression when they get to the hatchling stage.

Hatchling Stage
The hatchling stage is huge and encompasses the entire progression of the tiny tadpole emerging from its egg up through growing front limbs. This is the period that most people actually pay attention to their tadpoles. This is the traditional "pet" stage, as many people then release their frogs back into the wild once they get those front limbs.

The first section of the hatchling stage, steps 20 to 25 is the gills stage. During this time period the little tadpole has external gills to let it breathe in water. It develops a mouth so it can eat tiny plants. This stage ends when the external gills atrophy away.

The second section is what I consider to be the fun one. The tadpole begins to grow its back legs! Sections 26-30 are simply about a tiny leg bud forming, growing longer and longer. At section 31 the leg bud has a tiny foot paddle. By stage 37 it has five separated toes. At stage 41, the last in this section, the tiny buds of the front arms begin to show.

Four-Legged Stage
Now we get to the final part where the tadpole really turns into a frog. Step 42 has the front arms fully emerging. The remaining changes have the mouth growing larger, the tail reducing, and finally at stage 46 the tail is fully gone. We have a frog!

Green Frog

Tadpole Care Feeding and Raising - What do Tadpoles Eat and Need to Thrive?

Frogs and Toads in Sutton Massachusetts

Tadpole Care and FeedingTadpole Care and Feeding
This step by step manual helps ensure that your little tadpoles grow up to be happy, healthy frogs. From choosing the tank to designing the menu, from checking the pH to adjusting the temperature, I'll ensure your cute, tiny balls of energy grow up into a joyful friend.

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Sutton Massachusetts Photo Collection