Phyla Nematoda
Divneet, Mitali and Sachin
Germ Layers
Nematodes have three germ layers: endoderm, mesoderm and
ectoder- they are all triploblasts.
Symmetry
N
e
m
a
t
o
d
e
s
h
a
v
e
Coelom
Nutrients are transported throughout the body via fluid in
pseudocoelom.
Circulatory System
NONE
Respiratory System
NONE
Digestive Tract
- One way digestive tract running from mouth to anus.
- There is no stomach, pharynx connected directly to the intestine that forms main length of
gut.
Reproduction
There are two ways for nematodes to reproduce:
Usually, nemotodes mate with the opposite sex.
Reproduction is internal.
However, some are hermaphrodites. These nemotodes are
assexual. That means they have sex with themselves.
Segmentation
..
NO
SEGMENTATION
Habitats
Nematodes live in almost every habitat, being able to survive in
both extremely hot and cold conditions. Most live in the soil and
are decomposers. Parasitic nematodes also thrive in bodies of
organisms such as plants and humans.
Cephalization
Cephalization is the evolutionary trend towards centralization of
neural and sensory organisms.
Nematodes have cephalization nervous system.
They have a pseudocoelem, which is a body cavity of fluid.
Skeleton and Appendages
Nematodes have a hydrostatic skeleton- an enclosed volume of
water used to help muscles work.
The hydrostatic skeleton is maitained by cuticles and osmosis.
They do not have any appendages.