Do flatworms have a respiratory system?

Do flatworms have a respiratory system?

Flatworms have no specialized respiratory system; gases simply diffuse across the body wall.

What type of respiratory system do flatworms have?

Flatworms do not have a respiratory system. Instead, they have pores that allow oxygen to enter through their body. Oxygen enters the pores by diffusion.

How do nematodes breathe?

Nematodes are triploblastic protostomes with a complete digestive system. Roundworms have no circulatory or respiratory systems so they use diffusion to breathe and for circulation of substances around their body.

Do flatworms perform gas exchange?

In simple organisms, such as cnidarians and flatworms, every cell in the body is close to the external environment. Their cells are kept moist and gases diffuse quickly via direct diffusion. Flatworms are small, literally flat worms, which ‘breathe’ through diffusion across the outer membrane (Figure 20.3).

Do flatworms have eyes?

Planarian flatworms, which often live in dark, watery environments shielded from direct light, don’t have complex eyes like we do. But many do have two lensless, primitive “eyespots” on their heads that can detect the intensity of light.

Do flatworms absorb knowledge?

Biologists that sliced off the heads of trained planarian flatworms have discovered that the regenerative creatures can retain memories and transfer these to their new, regrown brains.

How do flatworms move?

Flatworms lack a respiratory or circulatory system; these functions take place by absorption through the body wall. Movement in some flatworms is controlled by longitudinal, circular, and oblique layers of muscle. Others move along slime trails by the beating of epidermal cilia.

Are flatworms Pseudocoelomates?

The flatworms are acoelomate organisms that include free-living and parasitic forms. The nematodes, or roundworms, possess a pseudocoelom and consist of both free-living and parasitic forms.

Do flatworms have teeth?

They inhabit freshwater, and are carnivores (even without teeth) or scavengers. Most are less than a centimeter long. (Click on either of the pictures above for a larger image). Flatworms were once divided into three groups.