Transcript Bio 126 Animal Groups - Diablo Valley College

Animal Groups
Bio 126 – Nature Study
Sponges
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Filter feeders
Simplest animals
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No muscles, no nerves,brain
Very flat, small in cool California waters
Sessile as adults
Cnidarians
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Sac-like gut (one opening)
Tentacles with stingers (nematocysts)
Have simple muscle-like contractile cells
Have a simple sensory cells in a simple
nervous network
Have Polyp and Medusa forms
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Corals are Polyps forms
Sea Jellies are medusa forms
Nematodes – Roundworms
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Bilateral symmetry
Cephalized (has a head)
Flow-through digestion
Hollow (pseudoceolomate) body
Common in
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Soil
Parasites on plant roots
Some are human parasites too !
Mollusks
Mantle
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May secrete shell -exoskeleton
Muscular Foot
Gills
Snails have scraping radula
Types of Mollusks
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Gastropods – Stomach-foot
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Chitons – 8 plates
Bivalves
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Snail, slug
Nudibranch
Clams, scallops, oysters, mussels
Cephalopods – Head-foot
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Squid, Octopus
Foot divided into tentacles
Most intelligent non-vertebrate
Annelids- Earthworms
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Circulatory system
Segmented worms
Hermaphrodites
Cuticle
Also:
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Leeches
Pile worms
Arthropods
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Hardened exoskeleton of chitin
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Molting between stages
Segmented body plans
Jointed appendages
Division of labor in lifecycle
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Larvae
Metamorphosis
Arthropod groups
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Insects
Spiders & mites
Crustaceans
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Crabs, crayfish
Barnacles
Millipedes & centipedes
Echinoderms – spiny skin
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Gone back to radial-like symmetry
Hardened spine skin
Internal skeleton
Tube feet
Water vascular system
Sea stars, sea urchins, sand dollars
Tunicates – sea squirts
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Cellulose tunica surrounds animal
Adult a sessile filter feeder
Larvae swims, has tails, nervous
system
Cartilaginous fish
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Sharks and rays
Bony fish
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Many types
Amphibians
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Still need water to breed
Juvenile still a fish
Thin, moist skin
Tetrapods
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Walks like a fish out of water
Reptiles
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Scaly skin, resists drying out
Amniote eggs –
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On land, in a moist nest in soil
Leathery shell
internal fertilization
Kidneys – conserve water
Aves- the birds
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Warm blooded
Feathers for insulation, later for flight
Hollow bones
Efficient respiration
Intelligent
Amniote eggs with hardened shell
Mammals
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Warm blooded
Hair for insulation
Nourish young with milk
Intelligent
Long Parental care period
Learned behaviors
Specific dentition