Invertebrates
Study Guide
Sponge
Sponge - one type of animal that filters the water it lives in to get food.
Example - Venus-Flower Basket,
Characteristics
- reproduce asexually
- can’t move once they attach as adults
- gets food from environment around it.
- between inner and outer layer there is a jelly-like layer
- grow at almost any depth
- grow on hard surfaces
- shaped like fingers, tree branches or round
- filters water to get its food
- 5000 known species
-no real digestive system
Adaptation - body is a network of tiny pores and canals that allow water to filter through to obtain food because they don’t move.
Source for pic.: http://animalstown.com/animals/s/sponge/wallpapers/sponge-wallpaper-2.jpg
Flatworms
Flatworm - has a flattened body, a digestive system with only one opening, and a simple nervous system. Example: Planarian
Characteristics
flattened body
digestive system with only 1 opening and simple nervous system
live in both freshwater and saltwater
bilateral symmetry
sense organs and nerve cords
a mouth and digestive system
can regenerate body parts that have been cut off.
Adaptation - Planarian can regenerate body parts
Segmented Worms
Segmented Worms - These are worms whose bodies are made up of connected sections, or segments. Example: earthworm.
Characteristics
body made up of connected segments
circulatory system - 5 enlarged tubes that act like hearts
nervous system - brain and main nerve
breath through skin
two sets of muscles that allow it to move
takes in food through mouth
reproduce sexually
Adaptation - breath through skin in the soil
Source for pic: http://media.web.britannica.com/eb-media/55/28355-004-64219017.jpg
Mollusks
Mollusk - an animal with a soft body and no bones.
Example: clams, oysters, slugs, snails, squids and octopods
Characteristics
some have a hard shell that protects their body
Mantle - shell of mollusk, produces material to harden shell, grows as animal grows
some the mantle is a tough layer of skin
muscular foot - helps move and burrow into ocean floor
reproduce sexually
some have bivalves like oysters and clams
Radula - organ in snail that acts like a tongue with sharp teeth
octopus and squid have well developed brains and nervous systems
Adaptations - octopus and squid have jet like motion and squirt ink, snail has has a hard shell that protects itself.
Echinoderms
Echinoderms - are invertebrates that have internal skeletons and spines sticking out from their bodies
examples: starfish, sand dollars, sea urchins, sea cucumbers
Characteristics
Interval skeletons and spines
live only in the ocean
get oxygen from seawater
most adults appear to have radial symmetry
spiny skin
endoskeleton
no head or brain
tube feet
Adaptation - Mouth is at the center of underside with powerful jaws and hidden among their spines and poison glands. They also have tube feet for moving, feeding and sensing respiration
Source for pic: http://4.bp.blogspot.com/_XpA_8S8IHDM/SRvSRm8QRDI/AAAAAAAABEI/qoyBPp9oj4w/s400/Sunflower-star.gif