Arthropoda Lab 3 PDF

Invertebrate Ecology Lab 3 2nd Year Arthropoda Characteristics of Arthropoda: 1. Arthropods have segmented bodies; the exoskeletons of arthropods are made up of calcium-containing compound called chit...

Invertebrate Ecology Lab 3 2nd Year Arthropoda Characteristics of Arthropoda: 1. Arthropods have segmented bodies; the exoskeletons of arthropods are made up of calcium-containing compound called chitin exoskeletons, and often have compound eyes. 2. They have open circulatory systems and complete digestive system. 3. Bilateral symmetry. 4. Jointed appendages- each segment may have pair of appendages, such as: legs, wings and mouthparts. 5. The nervous system is dorsal. 6. Respiration by gills, tracheae, or spiracle. 7. Muscular system is complex and muscles attach to the exoskeleton. 8. Arthropods reproduce sexually, but some exhibit parthenogenesis. 9. Arthropods must molt, or shed their exoskeleton, in order to grow in size. Classes of Arthropods Class Crustacea: e.g. Crab, woodlice, crayfish, shrimp 1. Body grouped into three regions: the head, the thorax, and the abdomen. The head and thorax may be fused together to form a cephalothorax. 2. Two pairs of antennae. 3. Five to seven pairs of legs. By: Dr. Nihal S. Hanna Invertebrate Ecology Lab 3 2nd Year 4. The majority of crustaceans are aquatic, living in either marine or freshwater environments, but a few groups have adapted to life on land, such as terrestrial crabs and woodlice. Crayfish Crabs Class Diplopoda: Millipedes 1. Two pairs of legs per body segment. 2. Most millipedes are detritivores and feed on decomposing vegetation, feces, or organic matter mixed with soil. 3. Have very elongated cylindrical or flattened bodies with more than 20 segments. 4. Nocturnal. Class Chilopoda: Centipedes 1. One pair of legs per body segment. 2. Centipedes are carnivorous and eat soil arthropods, snails, slugs, and worms. 3. Some species of centipedes can be hazardous to humans because of their bite in which the first pair of legs modified as venomous fangs. 4. Centipedes are mostly nocturnal predators. Millipedes Centipedes By: Dr. Nihal S. Hanna  Invertebrate Ecology Lab 3 2nd Year Class Arachnida: e.g. Scorpion, Yellow Garden Spider, Blacklegged Tick 1. Most arachnids have two body regions: cephalothorax and abdomen. 2. Most arachnids have four pairs of legs. 3. Antennae are absent. 4. Most contain venom. Scorpion Yellow Garden Spider Blacklegged Tick Class Insecta: e.g. ladybug 1. Three body segments: head, thorax and abdomen 2. One pair of antennae. 3. Usually two pairs of wings, although some have one pair of wings, or none. 4. Three pair of legs, one pair to each of the three thoracic segments. 5. Life cycle has either incomplete or complete metamorphosis. Roles of Arthropods in ecosystem: ✓ Pollination of flowering plants; Insects are essential to the pollination of most flowering plants. ✓ Recycling plant and animal matter; Many arthropods develop by feeding on dead plant matter, dead animal matter, or animal dung. In this role, they function as decomposers that are in the first-line “clean-up crew” essential to the recovery and recycling of nutrients. By: Dr. Nihal S. Hanna Invertebrate Ecology Lab 3 2nd Year ✓ Soil formation and mixing; The great majority of terrestrial arthropods live within the soil. These animals help to turn the soil and incorporate organic matter and nutrients. ✓ Centrality to animal food chains; Through their feeding activities, plant-feeding insects convert plant biomass to animal biomass. ✓ Use Arthropods as ecological indicators; their sensitivity to environmental conditions allows application of biological knowledge to identify aspects of environmental change. By: Dr. Nihal S. Hanna