Bimodal life cycle – abrupt transformation from a gilled aquatic form to an air breathing terrestrial form.

Exceptions:
• Some amphibians like the Slimy Salamander have direct development – larvae stay within the egg and tiny adults hatch out
• Some amphibians like the Axolotl are neotenic – the adults look like the larvae
• The Eastern Newt has a fourth stage, metamorphosing twice!
  Aquatic Egg – Larva – Terrestrial Eft – Aquatic Adult

Holometabolis – Complete Metamorphosis

• During the pupal stage, the insect does not eat.
• Butterflies, Beetles, Bees and Ants have Complete Metamorphosis.

Hemimetabolis – Incomplete Metamorphosis

• Nymphs often look like small, wingless adults.
• Nymphs go through gradual changes, molting several times.
• Dragonflies, have Incomplete Metamorphosis with an aquatic naiad.
• Grasshoppers & Mantids have Gradual Metamorphosis, (Paurometabolous) – the nymphs live in the same habitat as the adults.

Complex life cycle – requires another species

• The glochidia (larvae) of most mussels are parasitic – they attach to the gills or fins of fish
• They form cysts inside which then transform to juvenile mussels
• After transformation, they drop off their host
• The salamander mussel glochidia attach to mudpuppies