Presentation on theme: "Phylum Arthropoda General Characteristics. Largest phylum in the animal kingdom Includes insects, spiders, millipedes, centipedes, crabs and krill."— Presentation transcript:
Largest phylum in the animal kingdom Includes insects, spiders, millipedes, centipedes, crabs and krill. Are bilaterally symmetrical; coelomate; protostomate. Exoskeleton. Major component: the polysaccharide, chitin. Jointed appendages. Well-developed sense organs Open circulatory systems Group is important as pollinators of flowers, carries of disease, and as food. About 1+ million species known at present.
Class Arachnida Includes ticks, mites, scorpions and spiders Black-legged deer tick Acarina – Dust mite Striped bark scorpion Wolf spider
Class Arachnida Two body regions: cephalothorax and abdomen. Have 4 pairs legs attached to their thorax. A pair of chelicerae (fangs). A pair of palps. Function as sense receptors, short arms, and pincers (in scorpions).
Class Arachnida All arachnids are carnivores. Most eat insects. No antennae. Many have 8 simple eyes. Respire through book lungs and tracheae. About 57,000 species, including Latrodectus mactans (black widow spider) and Dermacentor variablis (wood tick).
Class Crustacea Includes crabs, shrimps, water fleas, and pill bugs. Blue-clawed crab Brown shrimp Water fleaPill bugs
Class Crustacea Most are marine, but some live in fresh water, and a few live on land. 2 main body regions in most. 5 pairs of legs (4 pairs for walking and 1 pair for grasping (chelipeds)).
Class Crustacea 5 pairs of head appendages, including 2 pairs of antennae and chewing mouthparts, which are useful in classifying them.
Class Crustacea Respiration by gills (most are aquatic). Many have compound eyes. About 35,000 species, including Callinectes sapidus (blue crab) and Homarus americanus (American lobster).
Class Merostomata Horseshoe crabs. All are marine. 2 main body regions. Easily recognized by horseshoe-shaped carapace and long telson. 5 pairs of legs (like crustaceans). No antennae (like arachnids).
Class Merostomata Respire through book gills (much like book lungs in arachnids). Have both simple and compound eyes. Only 4 species exist Superbly adapted to their environment from early in the history of life on Earth, they have changed little. Chesapeake Bay hosts largest population in the world.
Arachnida (spiders) Crustacea (lobster) Merostomata (horseshoe crab) 2 main body regionsYes 4 pairs of legsYes 5 pairs of legsYes True gillsYes Book lungs/book gills Antennae Chewing mouthparts Yes; book lungs No Yes Yes; book gills Yes Yes; book gills No Yes
Dust Mites vs. Bed Bugs Class Arachnida Class Insecta Why???
Class Chilopoda Two body regions (cephalothorax and abdomen). Have a head with one pair of long antennae and a pair of mandibles Two pairs of maxilla (appendages which hold their captured food and aid in chewing with side to side movement).
Class Chilopoda: Centipedes Carnivorous. Head followed by 15 to 177 body segments. First body segment has a pair of poisonous claws. All other segments have 1 pair of jointed legs Do not have 100 legs (as their common name suggests). Tracheae used for respiration. Vietnamese Centipede
Class Diplopoda: Millipedes Three body regions (head, thorax, and abdomen). Have a head with one pair of antennae and a pair of mandibles One pair of maxilla
Class Diplopoda: Millipedes Mostly herbivorous Head followed by 20 to 200 segments 2 pairs of jointed legs on each segment. Do no have 1,000 legs (as their common name suggests). Tracheae used for respiration.
Class Insecta Single largest class of organisms; more than 750,000 known species. Includes bees, flies, grasshoppers, lice, butterflies, moths, and beetles (450,000 species).
Class Insecta Three body regions Three pairs of walking legs Three pairs of walking legs located on thorax One pair of antennae on head.
Class Insecta Have complex mouth parts with one pair of maxilla and mandibles. When wings are present, have one or two pairs of wings on thorax. Two pairs on Dragonfly Mosquito has one pair of wings
Class Insecta Only group of invertebrates capable of flight. Tracheae used for respiration Have compound eyes Most live on land. Many have complete metamorphosis