- Sponges
- Are primitive animals.
- Filter feeders
- Beating flagella moves water
- Phagocytosis (choanocytes are phagocytic feeding cells).
- Respiration
- Structural Spicules
- Are monoblastic (one tissue layer)
- Sedentary
- Spongin - a modified collagen protein
- Reproduce sexually (fragmentation) or asexually (sperm).
Cnidarians
- Diploblast Cnidarians are carnivores.
- Aquatic, radial symmetry.
- Such as hydras (jellyfish).
- Have cnidocyte cells w/ nematocyst organelle that shoots out neurotoxin to capture prey.
- Polyp
- Sessile
- Medusa
- Motile
Arthropods
- Arthropods
- Land or water
- Exoskeleton outside the body made of chitin.
- Segmented bodies with paired, jointed, appendages.
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Crustaceans
- Insects Arthropod
- Have gas exchange by diffusion.
- Most have 2 pairs of wings.
- Body segments: Head, thorax, abdomen.
- Have mandibles
- Arachnids Arthropod
- 4 pairs of appendages = 8 legs
- Are all chelicerates (have fangs)
- Pointed mouths used for grasping.
-
- Not chewing mouthparts
- May have hollow chelicerae w/ venom.
- Tardigrades Arthropod
- Tiny water bears, hardy in dormant states.
- Are ecdysozoans that molt.
Types
- Lophotrochozoa
- Not segmented.
- Skeletons are internal, no shedding/molting.
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Mollusks
- Ecdysozoa
- Often jointed.
- Molting/shedding insects.
- External exoskeleton made of chitin.
-
Arthropods
Mollusks
- Largest group of marine animals (no joints).
- Have an open circulatory system (except cephalopods: squids, octopus).
- Mantle
- Fold of tissue secretes calcareous shell for protection.
- Mantle Cavity
- Contains gills for gas exchange of filter feeding.
Corals
- Are symbiosis of cnidarians (animals) and dinoflagellates (microbial eukaryotes).
- Coral provides protection, living space, nutrients.
- Dinoflagellates provide oxygen, food, increase calcification.