Phylum Arthropoda !

1. Phylum Arthropoda! By: Anna Grace Watkins

2. Arthropod Characteristics: • Arthropods pollinate many of the flowering plants on Earth. • Arthropods are bilateral symmetrical. • They have an exoskeleton and appendages. • An appendage is any structure, such as a leg or an antenna, that grows out of the body of an animal. • They help the arthropod with its sensing, walking, feeding, and mating. • Some arthropods have a head and a fused thorax and abdomen, but others have an abdomen and a fused head and thorax called a cephalothorax.

3. Characteristics Continued: • Arthropods must shed their old exoskeleton often. • They are very successful due to the presence of an exoskeleton. • This process is called molting. • They go through this because their exoskeleton can not grow, but before it molts, a new, soft exoskeleton is formed from chitin-secreting cells beneath the old one. • But while the new exoskeleton is soft ,they become very venerable to predators because they can not protect their selves. • Most arthropods molt four to seven times in their lives.

4. Characteristics Continued: • Most arthropods are segmented, but not as much as worms. • There are 3 sections: • Head • Thorax • Abdomen

5. Characteristics Continued: • Arthropods are mostly very quick! • They crawl, run, climb, dig, swim, and fly. • They have an open circulatory system with vessels that carry blood away from their hearts. • Also has a complete digestive system with a mouth, stomach, intestine, and anus. • Arthropods also reproduce sexually. • They have a wide variety of respiratory structure . • Gills, book lungs, & tracheal tubes! • Other openings in their body is spiracles.

6. Characteristics Continued: • Arthropods have acute senses. • Some can even communicate by pheromones, which are chemical odor signals given off by animals. • Their vision is also very important also. • Most have a pair of large compound eyes and from three to eight simple eyes. • Compound eyes can detect movements of prey, mates, or predators, and can also detect colors. • Arthropods also have well-developed nervous system that process information coming in from the sense organs. • Its simple nervous system consists of a double ventral nerve cord, an anterior brain, and several ganglia. • The ganglia acts as control centers for the body section in which they are located.

7. Class Arachnida: • 30,000 Species! • But only a dozen a harmful to humans. • Spiders are the largest group of arachnids. • Arachnids have 6 pairs of jointed appendages. • The first pair of appendages are called chelicerae. (pinchers/fangs) • The second pair of appendages are called the pedipalps. • The remaining 4 appendages are modified as legs for locomotion. • No antennae! • Has structures called spinnerets where the spider silk is secreted and is spun into thread. • 2 body regions. • The Cephalorthorax • The Abdomen

8. Class Arachnida Pictures: Spider: Scorpion:

9. Class Diplopoda: • Millipedes eat mostly plants and dead material on damp forest floor. • They do not bite, but can spray bad smelling fluids from their defensive stink glands. • There are estimated 8,000 species. • Centipedes are found in an array of terrestrial habitats from tropical rainforests to deserts. • they are found in soil and leaf litter, under stones and deadwood, and inside logs.

10. Millipede Pictures:

11. Class Crustacea: • Crustaceans are aquatic . • They exchange gas as water flows over feathery gills. • They are the only arthropods that have two pairs of antennae for sensing. • Some have 3 body sections & others only have 2. • Many have five pairs of walking legs that are used for: • Walking • Seizing prey • & cleaning other appendages • All have: • Mandibles for crushing food. • 2 compound eyes.

12. Class Crustacea Pictures: Lobster! Crab!

13. Class Chilopoda: • Centipedes are carnivorous and eat soil arthropods, snails, slugs, and worms. • When they bite you its very painful to humans. • They have Malpighian tubules for excreting waste. • Millipedes have tracheal tubes! • They may have from 15 to 181 body segments. • But they always have an odd number of segments.

14. Centipede Pictures:

15. Class Merostomata: • It includes only four living species. • These arthropods migrate to shallow water during mating season. • Female lay their eggs on land, buried in sand above the high water mark. • They possess compound eyes. • Also have a semicircular exoskeleton, and a long pointed tail. • They also have 4 pairs of walking legs. • 5 or 6 pairs of appendages that movie over their gills.

16. Class Merostomata Pictures:

17. Class Insecta: • Class Insecta is by far the largest group of arthropods. • Insects mate more than once, or less during their lifetimes. • The eggs are fertilizes internally and in some species, shells form around them. • Most lay a large number of eggs. • Females are equipped with an appendage that allows the insect to pierce through the ground or wood service to lay its eggs in the hole. • Some insects go through complete metamorphosis, where the insect goes through a series of developmental changes from egg to nymph. • Egg • Larvae • Pupa • Adult • Others go through incomplete metamorphosis , where the insect goes through only three stages of development. • Egg • Nymph • Adult

18. Class Insecta Pictures: Butterfly Grasshopper

19. The End!