The mechanism of locomotion in animals

Azneezal Ar-RashidSmk Sri Aman

95007 Sri Aman, Sarawak

February 2010

Hydrostatic skeleton

• Earthworm– Coelom : fluid-filled

chamber• Surrounded by :

– Circular muscle : » surround the

chamber– Longitudinal muscle :

» one end to another

• When circular contract, longitudinal relax– Thinner & longer

• When circular relax, longitudinal contract– Shorter & thicker

• Peristaltic waves– Front to end– Contract rhythmically – Bristles : chaetae

• Anchor parts– Other parts can be pull

Exoskeleton

• Grasshopper– 6 legs– Antagonistic muscles

• Flexor• Extensor

Endoskeleton

• Fish – Streamlined body shape– Overlapping scales (backwards)– Covered by a slimy coating– Flexible vertebral column– Myotomes

• W-shaped muscle– Opposite actions

• Unstable – Yaw : sideways

• Dorsal and ventral fins

– Rolling : transverse• Dorsal and ventral fins

– Pitching : vertical• Pelvic and pectoral fins

• Swim bladder– What is that? :

• …………………………………………………………

– Function? :• …………………………………………………………