Transcript Chapter 15 Invertebrates

Chapter 11 Invertebrates
Life Science
Body Plans
• Bilateral Symmetry—can be divided into two mirror
image halves
• Radial Symmetry—has parts arranged around a
central point
• Asymmetry—no symmetry
Body Plans
• Bilateral Symmetry—can be divided into
two mirror image halves
Body Plans
• Radial Symmetry—has parts arranged
around a central point
Body Plans
• Asymmetry—no
symmetry
All animals can be classified as
belonging to one of two groups:
Those
with
Backbones
OR
Those
without
Backbones
Animals
without Backbones
are called
Invertebrates.
Phylum Porifera (Sponges)
• Porifera are Sponges
found mostly in the ocean
• Porifera means “pore
bearing” because sponges
are covered in small pores
• They are the simplest of
all animals
• They are asymmetrical &
have no nervous system
Porifera
Sponges: Filter Feeders
• Water is swept into pores
• Collar cells filter food
particles from the water
– Each collar cell digests
its own particles of
food
• The rest of the water
flows into a central cavity
and into a hole at the top
called the osculum
http://www.youtube.com/watch?v=T7E1rq7zHLc
Phylum Porifera (Sponges)
• If a sponge’s body is
broken apart, separate
cells will come back
together and reform the
same sponge.
• New sponges can also form
from pieces broken off
another sponge.
• Sponges can replace body
parts, or regenerate
Phylum Cnidaria
• Cnidarians include jellyfish,
hydra & sea anemones
• The word Cnidaria means
“stinging nettles” because
they use nematocysts to
sting & capture prey
• They have Radial symmetry
and use a gut for digestion
Phylum Cnidaria cont’
• All have tentacles and stinging cells that fire tiny
barbed spears called nematocysts
• Feed by stinging their food and bringing it to the
mouth with tentacles
•
http://www.youtube.com/watch?v=-Tp38DUjUnM
Cnidarian Body Forms:
PolypShaped
like vases
and
usually
live
attached
to a
surface
Ex. Hydrafreshwater polyp
Ex: sea anemone
Ex: coral
Cnidarian Body Forms:
MedusaLooks like a
mushroom
with
tentacles
streaming
down
Ex. jellyfish
Phylum Cnidaria cont’
• They have a simple
nervous system,
called a “nerve net” &
a gut used for
digestion
– Nerve net- simple
network of nerve cells
that controls the
movements of the
body and tentacles
–
http://www.youtube.com/watch?v=Kuk
v0AtIVdU
Worms
Platyhelminthes
(flatworms)
Nematodes
(roundworms)
Annelids
(segmented worms)
Phylum Platyhelminthes
• Platyhelminthes means “flatworms”, meaning
they have flat bodies
• Bilateral symmetry
• Clearly defined head with a brain
• Nervous system- nerves connecting 2 parallel
nerve cords. Ganglia make up a primitive brain.
• Ex. Planaria
• Eyespots to detect light
• 2 Sensory lobes- on side of head, detect food
• Mouth is on under side – has only 1 opening
Phylum Platyhelminthes
Examples: Flukes & Tapeworms
• Parasites
– find their way inside the bodies of other animals,
where they live and reproduce
• Tiny heads without eyespots or sensory lobes
• Special suckers and hooks for attaching to the host
• Tapeworms have no gut
– They absorb nutrients from the intestine of host
Phylum Annelida
• Annelids are “segmented
worms” that include
leeches, earthworms &
bristleworms
• Each segment on their
bodies are identical except
the head
Phylum Annelida cont’
• Annelids have a closed circulatory
system- heart circulates blood through
blood vessels that form a loop
• They have a brain in the head & a
nerve cord that connect the ganglia
• Most Annelids will scavenge anything
edible or may be predators or even
parasites
Annelids
Example- Earthworms
• 100 to 175 segments
• Improve soil by burrowing tunnels,
which allow air and water to reach deep
into soil
• Stiff bristles (setae) help them move
Annelid: Earthworm
• Eat soil
• Food is taken in through the
mouth, swallowed in the
pharynx, travels through the
esophagus, stored temporarily
in the crop, ground up in the
gizzard, nutrients are
absorbed in the intestine, and
wasted is excreted through the
anus
Phylum Annelida cont’
Earthworm internal organs
Annelids
Example- Bristle Worms
• Many varieties and brilliant colors
• All live in water
– Some burrow through soggy sand and
mud
– Others crawl along bottom, eating
mollusks & other small animals
• Feeds by filter feeding
Annelids
Example- Leeches
• Most are parasites that
suck other animals’ blood
• Aren’t all bad
– used in medical
treatments
• used to drain “bad”
blood from sick
people
• now used after
surgery to prevent
swelling near wound
• Make a chemical that
keeps blood from forming
clots
Phylum Mollusca
• All Mollusks share a similar body plan
– They all have a:
• soft body (the word Mollusca means “soft
bodied”)
• usually covered by a shell
• foot used primarily for movement
• visceral mass that contains all the internal
organs
• mantle that secretes their shell
Mollusks
Mollusks have bilateral symmetry.
Digital Vision/Getty Images
Mollusks
• Mollusks have digestive systems with
two openings and a body cavity that
contains the heart, the stomach, and
other organs.
• Their nervous systems include eyes and
other sensory organs as well as simple
brains.
Phylum Mollusca
• Mollusks are classified by the location
of their foot
• Mollusks come in 3 distinct groups:
1. Gastropods- “stomach footed”
2. Bivalves- 2-shells
3.Cephalopods- “head-footed”
Phylum Mollusca: Gastropods
• Gastropods are the only Mollusks
to invade land
• Gastropods feed by scraping
algae from rocks with their
radula- scraping tongue
•
http://www.youtube.com/watch?v=mLVDwlrSq5U
Radula
under a
microscope
Phylum Mollusca: Gastropods
“Snail trail”
• Gastropods move using
their foot and a trail of
mucous
• Gastropod defense:
– Snails: hard shell
– Slugs: nocturnal & secrete
mucous
Phylum Mollusca: Bivalves
• Bivalves are filter feeders; they siphon in
water & filter out tiny particles for food
• They move by “clapping” their shells together
& defend themselves by burrowing in sand &
mud or close shells tightly
• Clams, Oysters, Scallops, Mussels
• http://www.youtube.com/watch?v=H5O1XYZcDh
8
Phylum Mollusca: Cephalopods
• Cephalopods are considered
the most intelligent of all
Mollusks
– Octopi have the largest
brain of any
invertebrate!
– http://www.youtube.com/w
atch?v=SCAIedFgdY0
• Cephalopods feed by
catching their prey with
their tentacles & bringing it
to their strong beak-like
jaw
Blue ringed
octopus
Cephalopod beak
Phylum Mollusca (Cephalopods)
• To defend themselves,
Cephalopods can even
change color to mimic
other animals or
camouflage to blend in
to their background
• They can also shoot out
ink
•
http://www.youtube.com/watch?v=tLTWFnGmeg&feature=related
• Cuttlefish
•
•
http://www.youtube.com/watch?v=pgDE2
DOICuc
Phylum Mollusca (Cephalopods)
• Cephalopods move using jet propulsion
• Other Cephalopods video clips
– Humbolt Squid
•
http://www.pbs.org/wnet/nature/episodes/encountering-sea-monsters/videohumboldt-squid-makes-contact/1032/
– Chambered Nautilus
–
–
http://www.youtube.com/watch?v=hcyzr3zJol4
Phylum Arthropoda
• Arthropod means “jointed limb” or
“jointed foot”
• They are covered with a hard
exoskeleton made of protein &
chitin
– provides stiff frame that
supports animal’s body
– allows animal to move
– acts as suit of armor to
protect internal organs
and muscles
– allows them to live on land
without drying out
• They have a well developed nervous
system with a head & brain and
bilateral symmetry
– most have compound eyes
• allow them to see images, not as
well as we do
Compound eyes
Antennae
Thorax
Segmented
body
Head
Made of chitin
Abdomen
Hard outer
skeleton
(exoskeleton)
Doesn’t grow
Brain
Complex
nervous
system
Live on
land and in
water
Arthropods
Stomach
Intestines
Complex
digestive
system
1.1 million
known
species
Sensory
organs
Open
circulatory
system
Heart
No
blood
vessels
Phylum Arthropoda cont’
• Arthropods are the largest group
of animals on Earth & have the most
diversity http://www.youtube.com/watch?v=pTQZAiuDoTg&feature=related
• Arthropods are classified by their body
parts
antennae- feelers that respond to
touch, taste, and smell
• They include, insects, spiders, crabs,
centipedes and many more
Arthropod Classes
 Insecta
 Bees
 Ants
 Grasshoppers
 Ladybugs
 Arachnida
 Spiders
 Scorpions
 Ticks
 Mites
 Crustacea
 Lobsters
 Crabs
 Shrimp
 Chilopoda
 Centipedes
 Diplopoda
 Millipedes
Class Chilopoda
centipedes
 Numerous
body
segments
 Flat bodies
 One pair of legs
per segment
 One pair of
antennae
 Lives on land
 Meat eaters

http://www.youtube.com/watch?v=V8gBvud9tts
Class Diplopoda
millipedes
 Numerous
body
segments
 Rounded body
 Two pairs of legs
per segment
 Lives on land
 Plant eaters

http://www.youtube.com/watch?v=tn2ZmbOUA2
M
Class Crustacea

•
•




shrimp, barnacles,
crabs, lobsters
nearly all are aquatic
and breathe with gills
2 compound eyes,
usually on end of
stalks
2 body segments
2 pair of antennae
10+ legs
Live in aquatic
environments
Class Arachnida






Spiders, scorpions, ticks, and
daddy longlegs
2 body parts: Cephalothorax
(head and thorax and usually 4
pairs of walking legs) and
abdomen and eat with their
chelicerae
No antennae
No compound eyes; spiders have
8 simple eyes in front of head
Some, like ticks can carry
diseases
Primarily lives on land
Class Insecta

3 body segments
• head- 1 pair of antennae
and 2 compound eyes, 3
mouthparts w/ 1 pair of
mandibles
• thorax- 3 segments with
1 pair of legs each (6
total), some have wings,
no wings, or 2 pairs of
wings
• abdomen

Live in a wide variety of
environments
Class Insecta cont’
• Insects change dramatically throughout
their live by a process called
metamorphosis
• Incomplete metamorphosis has three
stages:
– Egg, nymph & adult
• Complete metamorphosis has four
stages:
– Egg, larva, pupa & adult
Phylum Arthropoda cont’
Incomplete metamorphosis
Complete metamorphosis
Echinoderms- “spiny skinned”
• All are marine animals, most live on the sea floor
• Examples: sea stars, sea urchins, sea lilies, sea
cucumbers, brittle stars, and sand dollars
http://www.youtube.com/watch?v=D3W4OCnHyCs
• Have the ability to regenerate
•
http://www.youtube.com/watch?v=d5dOSyaKWTQ
Echinoderms
• Some prey on oysters and other shellfish, some
are scavengers, others scrape algae off rocky
surfaces
Echinoderm
• Tube feet
•
http://www.youtube.com/watch?v=4IRF-pKVtuU
• Body contains endoskeleton
– Internal skeleton similar to vertebrates
– Hard, bony, usually covered with spines
• Radial symmetry
• Simple nervous system
– Nerve ring around mouth
– Sea star has a radial nerve (controls arms)
• Water vascular system
– Water pumps that help animal move, eat, breathe,
sense environment
–
http://www.youtube.com/watch?v=HG17TsgV_qI