UNIT 8 ANIMALS

PHYLUM ARTHROPODA (jointed appendages) General information -most diverse of all animals -highly adapted Features -exoskeleton (chitin) -jointed appendages -segmented body -open circulatory system -sensory organs -compound eyes (most) 5 groups Trilobites (oldest fossils) Crustaceans Chelicerates (daggerlike mouth parts) Insects Myriapods (long bodies with many legs)

Crustaceans -marine Features -2 body sections: cephalothorax and abdomen -1 pr appendage per body section -2 pr attennae -exoskeleton -carapace

Appendages functions -collecting food -mating -protection

Appendages: Claws 2. Antennae 3. walking legs 4. Swimmerets 5. mandibles.

Types -decapods (10 legs) ex. Lobster, crabs -isopods (7 pr legs) ex Types -decapods (10 legs) ex. Lobster, crabs -isopods (7 pr legs) ex. Pill bugs,

Arachnids Largest group of chelicerates Ex Arachnids Largest group of chelicerates Ex. Spiders, ticks Horseshoe crabs, mites

Chelicerates Features -no antennae -4 pr walking legs -1 pr chelicerae -1 pr pedipalps poison gland spinnerets fangs

Examples Arachinds- live on land Features -8 legs -fanglike pincers, venon -silk glands 4 adaptations -waterproof cuticle -book lungs -Malpighian tubules -spiracles Diverse group -silk -venom

Insects Dominant terrestrial arthropods -most niches Features -3 body parts -head -thorax -abdomen

Metamorphosis -incomplete- miniature adults when hatched 3 stages -larva -nymph -adult

-complete – changes form entirely 4 stages -egg -larva -pupa -adult

Adaptation -flight occurred 400 myo Mouth adaptation -sucking -chewing -both

Arthropods and humans Share resources -herbivores that destroy crops -insecticides unwanted side effects Alternatives -arthropod specific insecticides -pest management -genetically modified crops

Vectors -carry diseases from 1 host to another Ex Vectors -carry diseases from 1 host to another Ex. Bubonic plague Yellow fever Malaria West nile virus