Shape of Life


Level of Organization

Flatworms have cells, tissues, and organs. They have eyes, a larynx, a mouth, ventrolateral nerves, and intestines.

Germ Layers

Flatworms have three germ layers: ectoderm, mesoderm, and endoderm.


Flatworms have bilateral symmetry.


Flatworms have cephalization. Cephalization is the creation of a head and the animal follows its head.

Body Cavity

Flatworms do not have any body cavities.


Flatworms are not segmented.

Digestive System

Flatworms have a combined digestive and excretory system. They take in food and get rid of it through the same opening. They eat small worms, insects, and microscopic matter.

Circulatory System

They have a gastrovascular cavity with one opening. Everything goes in and out of one opening.

Respiratory System

A flatworm takes in oxygen through the water, but does not have a formal respiratory system.

Excretory System

Any excess food/ solid is sent back through the mouth as waste. Water goes through excretory pores as waste.

Nervous System

Flatworms have a nervous system, but they do not have a brain. The eye holes only detect light. They have a nerve net and nerve cords that run through their bodies.


Flatworms are hermaphrodites. They contain both female and male reproductive organs. Can produce by asexual or sexual reproduction.


Flatworms do not have a skeleton. They use their muscle system as a way to support themselves and move.