Phylum Nematoda (Round worms)

My dad HATES these

Superphylum?

Ecdysozoa

Have a cuticle-

tough, flexible exoskeleton

Molt to grow

Cuticle made of collagen and chitin

Body Plan:

Bilateral

Tissues:

Triploblastic

Body Cavity?

Pseudocoelcomate

Cylindrical tubular morphology

Protosome

True

Live in all habitats

True

Some are ____ most are ____

free-living; parasitic

Simple cephalization

Cerebral ganglia rudimentary brain

Sensory papillae and bristles provide sense of touch

Digestive System?

Complete

Mouth, anus

Lips and teeth

Mouth, pharynx, intestines, exits anus

Circulatory system?

Lacks

Diffuse throughout body

Excretory system?

Has

Very simple

Metabolic waste is ammonia, removed via diffusion

Nervous System?

Has

Simple “brain”

Four longitudinal nerve cords emerge and travel down length of body

One nerve is dorsal, two lateral, one ventral (more developed)

Respiratory System?

Lacks

O2 and CO2 through epidermis

Limits thickness of body

Reproduction

Species specific

-Monoecious

-Dioecious

-Parthenogenic

In dioecious species fertilization:

Internal

Female lays eggs that develop approximately two weeks

Larvae molt four times ecdysis