Kingdom Animalia Invertebrate phylums Arthropoda and Echinodermata

VII. Phylum Arthropoda The largest animal phylum, there are more arthropods than all other phylums combined

Characteristics of Arthropods Jointed legs Bodies have 3 segments Head, Thorax, and Abdomen Well developed nervous systems Open circulatory systems Exoskeletons of protein and chitin (a carb.) This does not grow so arthropods molt (shed their exoskeleton)

5 Classes of Arthropods 1) Crustacea 2) Chilopoda 3) Diplopoda 4) Arachnida 5) Insecta

Class Crustacea Ex) lobsters, crayfish, crabs, shrimp, daphnia, barnacles Have 2 pair of antennae on head Marine, freshwater, and terrestrial

More Crustaceans Coral banded shrimp Daphnia (water flea) Horseshoe Crabs

Class Chilopoda-Centipedes -“100 legs”

Class Diplopoda-Millipedes -”1000 legs”

Class Arachnida-spiders, scorpions, ticks, mites -Usually harmless, even good because they feed on insects -Some are notoriously harmful Ticks-spread Lyme disease Scorpions-sting Mites-itching, allergies Poisonous spiders Brown recluse Black widow

More Arachnids Microscopic Mite Scorpion Orb Weaver Black Widow Brown Recluse

Class Insecta-Insects! More than 900,000 species in 27 orders Entomology-the study of insects Mostly terrestrial Why are they so successful? The only invertebrates capable of flight Tremendous variation in feeding habits Very high rate of reproduction & short life cycles Small size, they don’t need a lot of space

Insects have 3 separate bodies regions _____ Head ______ Thorax ___________ Abdomen

Other insect characteristics 1 pair of antennae 3 pairs of legs Specialized mouthparts Chewing-ants Sucking-butterflies Sponging-flies

Reproduction in insects Sexual! Insects undergo 1 of 2 possible series of developmental changes called metamorphosis Complete-egg-larva-pupa(cocoon)-adult Ex)moths, butterflies, bees, flies, beetles Incomplete-egg-nymph-molt-adult A nymph is an immature adult Ex)grasshoppers, crickets, cockroaches

Complete Metamorphosis

Incomplete Metamorphosis

Economic/Ecological value of insects How are insects detrimental? Destroy crops Spread plant disease like Dutch Elm disease Destroy property-termites, moths Transmit animal diseases Mosquitoes-malaria Tse tse fly-African sleeping sickness Fleas-plague

How are insects beneficial? Crop pollination Produce honey Destroy harmful insects Lady bugs, praying mantis Food for birds, frogs, fish Scavengers, feeding on dead plants and animals

Pesticides Often kill beneficial insects Harm humans and other animals Insects become resistant Alternative Biological controls Sterilization Hormone traps Natural predators

VIII. Phylum Echinodermata Echinoderms-”spiny skinned” Ex) sea stars, sea urchins, sea cucumbers, sand dollars All marine Adults have radial symmetry Have internal skeletons or tests Considered the most advanced invertebrates Early development is like that of vertebrates

Examples of Echinoderms