✓ Largest phylum of Kingdom Animalia.

✓ Over two thirds of all species on the earth are Arthropods.

Phylum – ArthropodaArthros=joint, podos= foot/appendages

✓ Organ-system level of organization, bilaterally

symmetrical, triploblastic, segmented coelomate

animals.(Haemocoelomates)

✓ Body is covered by thick chitinous exoskeleton to which

the muscles are attached.

✓ Body bears paired jointed appendages.

✓ Body consists of head, thorax and abdomen.

✓ Respiratory organs

1.gills,-(Prawn)

2.book gills,-(Limulus)

3.book lungs(Spider)

4.tracheal systems (Cockroach)

✓ Circulatory system open type.

✓ Digestive system complete.

✓ Sensory organs - antennae, eyes (compound and simple), sound receptors in crickets,statocysts or

balance organs are present.

✓ Nervous system consists of a dorsal brain and a ventral, ganglionated longitudinal nerve cord from

which lateral nerves extend in each segment.

✓ Excretion takes place through malpighian tubules.

✓ Sexes are separate (Dioecious).

✓ Fertilisation internal (terrestrial forms) and external (aquatic forms).

✓ They are mostly oviparous.

✓ Development may be direct(cockroach) or indirect (insects)

✓ Shows moulting (ecdysis).

Examples:

• Economically important:

Apis (Honey bee)

Bombyx (Silkworm)

Laccifer (Lac insect)

• Vectors:

Anopheles

Culex

Aedes (Mosquitoes)

• Gregarious pest:

Locusta (Locust)

• Living fossil: Limulus (King crab).

Apis (Honey bee) Bombyx (Silkworm)

Laccifer (Lac insect)

Musca domestica(house fly)

Limulus (King crab) Locusta (Locust)

Periplanata(cockroach)

Cancer (crab)Penaeus (prawn)

Eupagurus(Hermit crab) Lepisma(silver fish)Scorpion

Millipede Centipede

recap

❑ PHYLUM – ARTHROPODA✓ Largest phylum of Kingdom Animalia

✓ Body is covered by thick chitinous

exoskeleton to which the muscles are

attached.

✓ Body bears paired jointed appendages.

✓ Body consists of head, thorax and abdomen.

✓ Sensory organs - antennae, eyes (compound

and simple), sound receptors in crickets,

statocysts or balance organs are present.

✓ Excretion takes place through malpighian

tubules.