- The 6 phases of the frog life cycle
- 1- Mating
- 2- Spawning
- 3 eggs
- 4- The tadpole
- 5- Development of the tadpole
- 6- Metamorphosis of the frog
- References
The life cycle of the frog is called metamorphosis. Metamorphosis is the change in shape that occurs during the life of some animals. For the frog, reproduction and fertilization are seasonal events.
This is because their life depends on the consumption of plants and insects in the pond in which they live, and on the temperature of the water and air.
The combination of the hours of sunshine and the temperature tells the female frog that it's spring.
If the frog is in its adulthood, the pituitary gland secretes hormones that stimulate the ovary to produce estrogen.
The liver then secretes proteins from the egg white that are transported into the blood to enlarge the eggs in the ovary.
The 6 phases of the frog life cycle
1- Mating
Male and female frogs mate in water or on plants, depending on the species of frog.
The male then embraces the female in what is called the amplexus. He literally climbs on her back and wraps his arms around her, making the mating happen.
2- Spawning
The female frog releases the eggs for the male to fertilize them. Unlike mammals, in frogs fertilization occurs outside the body. Spawning is the beginning of the frog's life cycle.
3 eggs
Most of the eggs will not thrive. Some will be food for other small animals and birds, and some will not be fertilized. There will also be some that will dry in the sun in areas where there is no water.
Eggs that survive will hatch about 7 to 9 days later. But they won't be frogs yet, they will have to go through the tadpole's life cycle first.
4- The tadpole
The tadpole is a small fish-like creature. In the first 7 days of life, the tadpole feeds on the white of the egg that it still has inside.
The only parts a tadpole has are the tail, mouth, and gills. After 7 more days of development, the tadpole will be able to swim by itself and eat algae from the surface of the water.
5- Development of the tadpole
After four weeks of life, the tadpole begins to grow teeth, and also skin on the gills.
Furthermore, it becomes a social being and swims in groups like fish. Between weeks 6 and 9 the tadpole begins to grow in size and develop a head and leg shape.
At the end of week 9 the tadpole looks more like a frog than a fish, but with a long tail. At this stage it also begins to feed on small insects.
6- Metamorphosis of the frog
Between weeks 9 and 12, the frog's metamorphosis really begins to take shape.
The tadpole, which at the time looks like a small frog with a long tail, loses most of its tail. It also grows a frog's tongue and begins to look like a small frog.
Finally, the life cycle is completed in about 16 weeks, when the frog becomes an adult.
References
- Berger (2005) Life cycle stages of the amphibian chytrid Batrachochytrium. 12/12/2017. int-res.com
- Ash (2003) Dialogic inquiry in life science conversations. 12/12/2017. onlinelibrary.com
- Miaud Claud (1999) Variations in life historytraits in the common frog. 12/12/2017. cambridge.org
- Editor (2002) The frog life cycle. 12/12/2017. Developmental Biology. nlm.nih.gov
- Editor (2015) Frog life cycle. 12/12/2017. Australian Museum. australianmuseum.net.au