Animals:Lifecycle

Animal Lifecycle

Animals that Grow Up (Simple Life Cycle):

Most animals including fish, mammals, reptiles and birds have very simple life cycles:

  • they are born (either alive from their mother or hatched from eggs)
  • they grow up

These animals have three stages — before birth, young and adult.  The young are typically similar to the parent, just smaller.  The young slowly “grow” to become adults.

Amphibians:

Amphibians, like frogs and newts, have a slightly more complicated life cycle.  They undergo a metamorphosis (a big change):

  • they are born (either alive from their mother or hatched from eggs)
  • they spend their childhood under water, breathing with gills
  • they grow into adults and move to the land, breathing with lungs

Animals that Undergo a Complete Metamorphosis:

Insects

These insects have four stages in their life cycle:

  • egg:   unborn stage.
  • larva:   young stage — this is when most of the feeding is done.(they usually look like worms)
  • pupa:  inactive (no feeding) stage between larva and adult stages.(usually well camouflaged)
  • adult:   final, breeding stage.(they usually grow wings)

Animals that Undergo an Incomplete Metamorphosis:

About 10% of insects go through an incomplete metamorphosis.  They do not have a pupal form — these include dragonflies, grasshoppers and cockroaches.

These insects have three stages in their life cycle:

  • egg:   unborn stage.
  • nymph:   young stage — this is when most of the feeding is done.
  • adult:   final, breeding stage – including wings.

Below are pictures of some important lifecycle stages.

 lifecyc

lifecycle-froglifecycle-chick