Invertebrates Flashcards
What phylum do Cnidarians belong to?
Eumetazoans
Scientific name for sponges
Porifera
How do sponges feed?
-Suspension feeders:
Capture food particles suspended in water
-Water is drawn in through the Spongocoel and out through the Ocsculum
What do sponges lack?
True tissues and organs
Choanocytes
-Flagellated cell that generate a water current through sponge and ingest suspended food
Amoebocytes
Small symbiotic organisms found in the mesophyll that aid in digestion
Cnidaria
Sessile- corals, anemones
Motile- jellies, hydras
Contain a gastrovascular cavity
Polyp
Adheres to the substrate
Found on cnidaria
Medusa
Cnidaria that have bell-shaped body with mouth on their underside and can move
Cnidocytes
Unique cells that function in defense and prey capture
Nematocysts
Specialized organelles within cnidocytes that eject a stinging thread
Flatworms (Lophotrochozoa)
- Gastrovascular cavity with one opening
- Gas exchange on surface
- Dorsoventrally flattened shape maximizes surface area for gas exchange
Molluscs
- Snails, oysters, octopuses
- Many marine, some freshwater, some terrestrial
- Soft bodies, hard shells
- Muscular foot
- Visceral mass
- Calcium carbonate shell
Bivalves
- Aquatic, includes clams and oysters
- Shell divided into two halves held together by adductor muscles
- Limited motility in some
Arthropods
- Nearly all habitats
- Segmented body
- Hard exoskeleton
- Jointed appendages
- open circulatory system where hemolymph is pumped around tissues
Insects
- evolution of flight was important for survival
- many undergo metamorphosis
Echinoderms
- starfish
- slow moving/sessile
- thin epidermis covers exoskeleton of hard calcareous plates
- radial symmetry
- water vascular system
Water vascular system
A network of hydraulic canals branching into tube feet
-functions in locomotion, feeding, respiration and waste removal
Sieve Plate
Intake valve that allows water to enter the vascular system
