Simple Invertebrates

Is a snake an invertebrate?

Characteristics
• Have no backbone
• Includes sponges
• Cnidarians ( jellyfish )
• Flatworms
• Roundworms, segmented worms and mollusks ( clams )

Sponges

Sponges
• Sketch
• Label top opening, flagella, body, pore

Sponges
• Are called FILTER FEEDERS because they take in dirty water and excrete clean water
• Use hairs called FLAGELLA to keep water moving through the sponge

Sponge Reproduction
• Asexual: use budding to grow an exact clone on their body
• Asexual: use regeneration to grow back body parts
• Sexual: use egg and sperm which combine to form larva

Sessile
• An organism that stays attached to one spot its entire life.

Flowers of the sea?

CNIDARIAN
• Jellyfish, Sea anemone, coral, hydra
• Sketch and label with tentacle and mouth

Heniochus acuminatus eating jellyfish

Sea anemone eating a jellyfish

This turtle thought the plastic bag was a jellyfish… he will probably die

Jellyfish
• Catch prey with stinging tentacles
• Sexually : use sperm and egg which combine to form larva

Jellyfish life cycle

• Sketch, label tentacles, top opening
Hydra

• Catch prey with tentacle
Hydra

Hydra
• Reproduce asexually by budding
• Describe: baby grows on parent , drops off

Invertebrates are not plants b/c
• They eat for energy
• Do not have chlorophyll

Radial Symmetry
Body parts the same around a central point

Bilateral symmetry
• Body parts same on 2 sides of a line

Asymmetry
• No line of symmetry

Page 357

Flatworms
• Bodies are soft
• Examples are planaria and tapeworm
• Most are parasites, which lives on a host and harms it

Planaria
• Body: flat, triangular head
• Eat dead meat and plants
• Live in fresh water
• Move with cilia
• Reproduce by splitting in two
• Hermaphrodite: both male and female in the same body

Tapeworms
• Attach to host with hooks or suckers
• Gets digested food from host

Roundworms
• Found in soil , animals , plants , fresh water , and salt water (everywhere!!!!)
• Humans catch them by walking barefoot through contaminated fields

Roundworm mouthparts

Tick into skin, acting as a vector

Very graphic picture coming up

Guinea worm
Dracunculiasis

Pinworm

Trichinella
• can be prevented by cooking meat thoroughly
• There is no cure

Dogs get heartworm
• by mosquito bites
• We call the mosquito a vector

Lumbricus terretrius

Anterior
• Above the waist

Posterior
• Below the waist

Dorsal
• On the back side

• Belly side
Ventral

• Setae
• 4 pr/segment…Bristles for movement
• (no skeletal system)
#1

• Mucous
• Keep skin wet for respiration…No lungs
• (no respiratory system)
#2

#3
• Segments
• Movement… Holds organs in place
• Muscular system

• 4a) Brain
• 4b) nerve cord
• Color same color
• Senses…Sends signals to organs
• Nervous system
#4

• Mouth
• Ingestion
• Digestive system
#5

• Pharynx
• Swallowing
• Digestive system
#6

• Crop
• Stores food
• Digestive system
#7

• Gizzards
• Grinds food
• Digestive system
#8

#9
• Intestine
• Digests and absorbs food into circ system
• Digestive system

#10
• Anus
• Excretes castings (good fertilizer)
• Digestive system

• Aortic arches or hearts
• Color reddish
• Pumps blood
• Circulatory system
#11

#12
• Dorsal and ventral blood vessel
• Color reddish
• Takes blood to rest of body
• Circulatory system

• Nephridia
• 2 per segment
• Filters liquid waste, excretes it thru skin
• Excretory system
#13

Worm Grunting
• To get worms to the surface, act like a mole
• Click here
• Why does it work?
• Click here