PHYLUM - ARTHROPODA:sparkle:
Arthropoda is the largest phylum of animalia which includes insects. Overtwo-thirds of named species on earth are arthropods
Body is Bilaterally symmetrical, Triploblastic with organ system level of organisation
They are metamerically segmented and coelomate animals.
Body is divided into three region Head, thorax & abdomen, but in some head and thorax fused to form cephalothorax(Prosoma)
They have jointed appendages for different functions. (arthro - jointed, poda- foot/appendages).
The body of Arthropods is covered by Chitinous exoskeleton
Respiration by gills (e.g.Prawn), Book-gills (e.g.King crabs). Tracheal system (e.g Insects), Book-lungs(e.g.Scorpion), Trachea carry oxygen directly to the body cells
Circulatory system is Open type
Sensory organs like simple eyes, or compound eyes or both, antennae, statocyst and anal cerci are found.
They are mostly dioecious. Fertilization is usually internal but few aquatic form has external fertilization.
Gonads have ducts. Sexual dimorphism may be present. They are mostly oviparous.
Dovelopment may be direct or indiret.
Gregarious pest - Locusta (Locust)
• Living Fossil - Limulus (King crab)
