The Animal Kingdom

Arthropods

The Animal KingdomCharacteristics:

Eukaryotic (nucleus)Heterotrophic: must consume their foodAll are multicellular

Possess no cell wallTypically have nerve tissue to conduct impulses and muscle tissue for movement Sexual reproduction is typical

The Animal KingdomReview the branch points in animal evolution.

Animals:heterotrophic,multicellular,no cell wall

The Animal KingdomReview branch points in animal evolution.

1st = presence of tissuesSponges have none.

2nd = symmetryNone (Sponges)Radial (Cnidarians)Bilateral (Worms)

3rd = type of bodycavity – a coelom

None (acoelomate: Sponges, Cnidarian,

Flatworm)Present (coelomate: Nematodes, Annelids,

Mollusks, Arthropods)

Phylum ArthropodaThe arthropods - insects, centipedes, spiders,

crabs, lobsters, (and the roly-poly)

Arthros + podes: Greek for jointed feet. Jointed appendages for walking &

grasping; also antennae, mouth-parts (like pincers).

All are segmented, but segments usually fuse into regions such

as head, thorax, & abdomen.All have exoskeletons that are replaced as animal gets larger.

Phylum ArthropodaThe arthropods - insects, centipedes, spiders,

crabs, lobsters, (and the roly-poly)

Distinct male and female formsOrgans of respiration*

*Insects have spiracles; lobsters have gills.

Phylum ArthropodaThe arthropods - insects, centipedes, spiders,

crabs, lobsters, (and the roly-poly)

Possess an open circulatory system: blood is dumped into the body cavity and must find its way back to the heart.

Phylum ArthropodaTrilobite:

early arthropod, became extinct 245 mya.

Phylum ArthropodaClass Arachnida (arachnids): Spiders, scorpions,

tarantulas, mites, & ticks.Two body segments: Cephalothorax + abdomen,Four pairs of legs,

Chelicerae: poison- delivering fangs.

Poison: works fast; no need to wrestle

to kill prey.Pedipalps: appen-

dages behind fangs manipulate

prey.Spinnerets: spiders make liquid silk (a protein),

solidifies in air. Silk is elastic and as strong as nylon.

Phylum ArthropodaClass Arachnida (arachnids): Spiders, scorpions,

tarantulas, mites, & ticks.Two poisonous spiders in Florida:

Brown recluse (violin on head)→ Black widow (hour-glass).

Banana spider (left)

Phylum ArthropodaClass Arachnida (arachnids): Spiders, scorpions,

tarantulas, mites, & ticks.Scorpion: 1st animal on land 400 mya.

Phylum ArthropodaClass Arachnida (arachnids): Spiders, scorpions,

tarantulas, mites, & ticks.Deer tick causes Lyme disease (right)

Dust mite x 10,000

Phylum ArthropodaClass Insecta (insects): over 800,000 species

Anatomy: 3 body regions - head, thorax & abdomen.Antennae: appendages on head to sense the environment.

Phylum ArthropodaClass Insecta (insects):

Tracheae: tubes in body thru exoskeleton that exchange air

Open through spiracles to outside.

Phylum ArthropodaClass Insecta (insects):

Mandibles: jaws instead of the chelicerae of spiders.Mouthparts: for grinding, scraping, piercing, sucking.Legs: for walking (beetle), jumping (flea), clinging (lice).

Phylum ArthropodaClass Insecta:

Metamorphosis: “change”; adult form different from young

Incomplete - young (nymph) is smaller version of adult with no wings or repro organ: grasshopper, dragonfly.

Phylum ArthropodaClass Insecta:

Metamorphosis: “change”; adult form different from young

Complete - young (larva) totally different, reduces competition with adult for habitat or food: butterfly larva eats leaves & adult eats nector. Also beetles, ant, bee.

Phylum ArthropodaClass Insecta: Social activity: ant, bee, termite.

Workers gather food, build tunnels, tend queen and others;Soldiers defend the colony (a collection of individuals);Queen and King only reproduce.

Phylum ArthropodaClass Insecta: Beneficial insects:

Pollination of crops: bees pollinate oranges, cotton, etc.Commodity production: honey, silk, larva as food (Survivor)Biocontrol of pests: lady beetle eats aphids, replace pesticide

Vital link in food webs: freshwater fish, amphibian, reptile.

Phylum ArthropodaClass Insecta: Harmful insects:

Destruction of crop (beetle; aphid, etc.) Disease transmission (mosquito & flea) →→ (bubonic plague)Human parasites

crab louse, or head louse)

Millipedes (10,000 species) & centipedes (2,500 species):

Anatomy: Millipede = thousand feet; all herbivores. Centipede = hundred feet; all predators - eat worms, insects. Produce venom (poison); non-lethal pain for humans.

Centipede – 2 legs per segment

Millipede – 4 legs per segment

Class Crustacea (crustaceans): Lobsters, crabs, & shrimp;

30,000 species in all.Anatomy: appendages for swim-

ming, crawling, burrowing.Antennae and mandibles like insects.Gills: for breathing so most

never adapted to dry land; except the pillbug.

Class Crustacea (crustaceans): Lobsters, crabs, & shrimp; 30,000 species in all.

Pill bugs are isopods - 7 pairs of walking legs.Decapods: 5 pairs of thoracic legs for lobster.Barnacles attached to rock at shoreline, boats, or sides of whales.

The Animal Kingdom

Echinoderms

Phylum EchinodermataThe 4th branch point is

embryo developmentStarfish & humans

are more closely related than insects

and humans.

Phylum EchinodermataEchinoderms “spiny skin”.

Bilateral symmetry as larvae: & radial symmetry as adults, which have a 5-part body plan.

Sea star Sand dollar Sea urchin

Sea cucumber

Phylum EchinodermataEchinoderms “spiny skin”.

One innovation is the endoskeleton (inside the body).

Ossicles are made of calcium carbonate, not bone.

Phylum EchinodermataEchinoderms “spiny skin”

Each leg contains organs for reproduction and digestion.

Most have male and fe-

male forms.

Phylum EchinodermataEchinoderms “spiny skin”

Breathes through gills.A water vascular system provides suction to tube feet to move the animal and apply force to open clam shells.

Phylum EchinodermataEchinoderms “spiny skin”

The stomach extrudes into a clam to digest outside the body..