Compare and Contrast ( Earthworm and Crayfish)

     Movement
                                                                               
Earthworm :
 Earthworms move with their sete                   
which are tiny feet like things that help them to move.  
the earthworm has a hydro static skeleton meaning it   
absoultly needs moisture.
Crayfish: The crayfish have an external skeleton.
To move around they use their swimmeretes and tail called the
telson to move.

Reprouduction:
Earthworm: Earthworms are hermaphrodites meaning
they are both male and female, they can mate with eachother, but not themselves.
Crayfish: crayfish reprouduce sexually, the male attaches a sperm pack on the underside of the females belly, she then curls up her tail and attaches the eggs to her swimmeretes.

Habitat:
Earthworm: they live in the soil, and are commonly found in gardens
because of the nutrients. They prouduce mucus to breath through their skin and transfer sperm.
Crayfish: Crayfish are found in fresh water, salt water, and ponds.
They hide from predators in grass and mud. They breath by extracting o2 from water using their gills
,gills provide a large surface between blood and water so o2 can diffuse from water into blood well.


Nervous System:
Earthworm:
The earthworms brain is connected to the vertral nerve cord which runs down its body, at each segment segmental ganglionnbranch from vertral nerve cord which connects every segment to the earthworm.
Crayfish: Crayfish nervous system is made up of a ganglion connected by a circumoral commissures with the post -oesophageal ganglia. these together constitute the brain. from the brain backwards streches the ganglionated cord.