Download Invertebrates - Brewton City Schools

Invertebrates I
Animal Characteristics
What is an Animal?
• Animals are Eukaryotic,
multi-cellular organisms
with ways of moving
that help them
reproduce, obtain food,
and protect themselves
• They are
vertebrates/invertebrates
Methods for Obtaining Food
• All animals are
heterotrophic – they
obtain energy &
nutrients from outside
sources.
Ingestion/Digestion of Food
• Animals ingest organic
material (food) in the form of
other living things
• Animals then digest or break
down their food once
consumed
• Some digest: internal cavity
example: monkey, earthworm,
frogs…
Other examples
• Sponges & Flatworms
digest within
individual cells. This
is known as filterfeeding
Sessile – a method
• Organisms that are
permanently attached
to a surface are called
sessile
• Some aquatic animals,
such as corals and
sponges move about
only during the early
stages of their lives
Growth & Development
• Most embryos
continue to develop
and resemble the adult
• Some embryos
develop into a larva
Sea Urchin Larva
Adult Sea Urchin
Development of Animals
• Most animals develop
from a fertilized egg cell
called a zygote.
• This is where two
haploid gametes fuse
• The diploid cell then
undergoes repeated
mitotic division
• After fertilization,
developmental stages
take place
CLEAVAGE
• Mitotic division
• The series of cell
rapidly
divisions that occurs
increases the
immediately following
number of cells,
fertilization is
but they do not
cleavage
grow in size
• The number of cells
increase from 2 to 4,
then 8 & so on
Blastula
• Cleavage produces a
raspberry-shaped mass of
16 to 64 cells
• As the number of dividing
cells increases, the mass
becomes a hollow ball of
cells called blastula
• The central cavity of a
blastula is called
blastocoel
Picture of Sea Urchins Forming
Into Blastula Embryonic Cells
Gastrula
• The next stage of
development, the area of the
blastula begins to collapse
inward. This process is
called gastrulation.
• This transforms the blastula
into a multi-layered embryo
called the gastula
Endoderm (Inner Surface)
Ectoderm (Outer Surface)
Gastula
• The deep cavity is called the archenteron
(c)or primitave gut
• The open end of the archenteron is called
the blastopore (e)
• Forming the outer layer of the gastula is
the outer germ layer is the ectoderm (a)
• The inner germ layer is the endoderm(d)
• The blastocoel (b) remains from the
blastula stage
• As development progresses, a 3rd layer
forms between the endoderm and
ectoderm called the mesoderm
Sperm cells
Fertilization
Egg cell
Formation of
mesoderm
Endoderm
Mesoderm
Ectoderm
First
cell
division
Gastrulation
Cell
Differentiation
in Animal
Development
Additional
cell
divisions
Formation of a blastula
Body Plans
• Body cavities make it
possible for animals to
grow, move, & feed
• Acoelomate: animal's
with 3 cell layers with
a digestive tract but no
cavities
• Flatworms
Ectoderm
Mesoderm
Endoderm
Body
cavity
Digestive
tract
Pseudocoelomates
Pseudocoelomate Roundworm
Ectoderm
Mesoderm
Endoderm
Body
cavity
Digestive
tract
• A roundworm is an
animal with bilateral
symmetry.
• The body of a
roundworm has a
space that develops
between the
endoderm and
mesoderm.
• Pseudocoelomates
means false cavity
Coelomates
Coelomate Segmented Worm
• The body cavity of an
earthworm develops from
a coelom, a fluid-filled
space that is completely
surrounded by mesoderm.
Ectoderm
Mesoderm
• The mesoderm lines the
body cavity and surrounds
& supports the
endodermic gut
– The mesoderm also forms
the tissues of attachment
for the organs (liver &
lungs)
Endoderm
Body
cavity
Digestive
tract
Coelom
ProtostomesFirst Mouths
• In embryos of mollusks, arthropods, and annelids,
the blastopore develops into a mouth, and a second
opening forms at the other end of the archenteron
forming an anus
• These animals are called a protostome.
Mollusk
DeuterostomesSecond Mouth
• In the embryos of echinoderms and chordates,
the blastopore develops into an anus, and a
second opening at the other end of the
archenteron becomes the mouth.
• These organisms are called deuterostomes
Chordata
What is symmetry?
• Each animal has a
different shape or
form because each
have a different
symmetry
• Symmetry refers to a
balance in proportion
• Different symmetry
helps an animal move
& find food
3 types of Symmetry
1. Asymmetry
2. Radial Symmetry
3. Bilateral Symmetry
Asymmetry
• Most sponges live on
the bottom of the
ocean & have irregular
shaped bodies
• They exhibit
asymmetry b/c they do
not have a equal
division body plan
Radial Symmetry
• Radial symmetry is
animals that can detect
& capture prey
coming toward any
direction
• Animals can be
divided along any
plane
Bilateral Symmetry
• Can be divided down
its length into similar
right & left haves to
form mirror images of
one another
•
1.
2.
3.
4.
Body Portions
consist of:
Anterior: head end
Posterior: Tail end
Dorsal: Back surface
Ventral: Belly
Surface
Body Portions
POSTERIOR
DORSAL
VENTRAL
ANTERIOR
Sponges
Phylum: Porifera
Meaning “Pore-Bearer”
What is a sponge?
Red Barrel sponge
• Invertebrate
• Asymmetrical animal
• Variety of colors,
shapes & sizes
• 5000 species
• Most in ocean, few in
freshwater Sessile
organisms
How do sponges feed?
• Filter feeders
• Nutrients are also
distributed through
the body by
amoebocytes, cells
which crawl about
within the body
wall.
• Many can filter
their entire body
volume in less than
one minute
Reproduction
• Asexual
-Budding
-Fragmentation
• Sexual
-Hermaphrodites
Sponge Defense
•Acoelomate
•Intracellular Digestion by
individual cells in the
gastrovascular cavity
Spicules
Tube sponge
Types of Sponges
Silk Sponge
This Purple Tube Sponge colony lives on a dead coral head.
The coral has algae and sponges that grew over the polyps
and killed them.
Cnidarians
“Cnidos”: Greek for stinging
Nettles
Jellyfish, Corals, Sea Anemones &
Hydras
What is Cnidarians?
•
•
•
•
•
•
Group of marine invertebrates
9000 species
Found world wide
Prefer warmer waters
All are radial symmetry
Body has 1 opening-2 layers
endoderm/ectoderm
Basic Body forms
Polyp
Medusa
Polyps
• Polyps: tube shaped body with a mouth
surrounded by tentacles
• Reproduce asexually by budding
Medusa
• Medusa: body shaped
like an umbrella or
bell shaped with
tentacles hanging
down.
• Reproduce sexually to
produce polyps
• Feed through a
gastrovascular cavity
Jellyfish Body Plan
• Instead of a brain
"true" jellyfish
possess:
• elementary nervous
system which can
detect light, odor and
other stimuli
Capture Prey With Nematocysts
• Thread like tubes w/
toxic substances
• May be sticky or
barbed
• Discharge like a
popgun
Various Species of Cnidarians
Hydrozoa:
•
Portuguese Man-of-War
May live individually or as colonies
Called Blue Bottle- the float is a
single individual & supports
the rest of the colony.
It secretes its own gas which is
similar to air.
Hydrozoa:
• Hydra
best known
never goes through the
medusa stage & remains a
polyp its whole life.
Species of Cnidarians
Scyphozoans:
• Jellyfish
are fish eaters
-Plankton
-main food source for sea
turtles
What to do if stung?
•Meat tenderizer
•Credit card / drivers license
•Sand
•Lifeguard
Floating Medusa’s of the Ocean
Box Jelly
Comb jelly
Blue Jelly
Lion Mane Jelly
Harmless Moon Jelly
Common to the Gulf Coast
Over the past several years, the Gulf Coast has seen an
increase in the number of jellyfish. WHY?
Purple Jelly
Stinging Nettles
Moon Jelly
Cannonball Jelly
Invasive Species
Australian spotted Jellyfish.
• Size of a basketball
• As Polyps & Medusa,
followed Jack-up Gas
Rigs to the Gulf Of
Mexico.
• Had economical
impact on shrimp
population for
Alabama
Freshwater Jellyfish
Polyp
Are not true Jellyfish
Eat zooplankton
Found in calm, freshwater
lakes, reservoirs & man
made impounds or gravel
pits.
Basic anatomy of a jellyfish
Species of Cnidarians
Anthrozoan
Coral
Sea Anemones
Sea Fans
Found 10-40 feet
Sea Pens
Flatworms
phylum: Plathyhelminthes
Characteristics of flatworms
• 20,000 different
species
• Acoelomates w/ thin
body layers
• Range in size: 1 mm –
several meters
• Bilateral symmetry
• Marine flatworm is
Largest free-living
flatworm
Live:
oceans: bright colored
parasites: in bodies
• One body opening
Planarians
The body:
• Defined head
• Pharynx
• Hair-like Cilia
• Eyespots
• Sensory Pits
• Flat bodies: dorsal &
ventral sides
Found: shallow streams
stuck to bottom of
rocks.
Feed: dead or slow
moving organisms
Planarians Regenerate
Planaria are noted for their great ability to
regenerate missing body parts.
Tapeworm
• Contracted from
eating uncooked pork,
beef or fish.
Body Plan:
• Scolex: (head) covered
with hooks
• Progottid: (body)
segmented
Flukes
•The adult flukes deposit eggs in feces .
•Ingested by a snail - (first intermediate host)
•released from the snail and penetrate freshwater fish
(second intermediate host)
•host (cats, dogs, and various fish & humans)
•Undercooked fish
Roundworms
phylum: Nematoda
About roundworms
• Found in soil, animals,
freshwater & saltwater
environments
• Free living/parasites
• Tapered at both ends
• Smaller than
flatworms
• 2 body openings
Hookworm
•Worms crawl to the nearest moist soil area and extend body into the
air – waving back and to
•Come in contact w/ bare foot or bare skin
•Larvae enter bloodstream & are carried to the lungs
•Migrate from the lungs up the windpipe to be swallowed and
carried back to the intestine.
Pinworms
•Most common roundworm, affects 1/3 children
•Small, thread-like worms found in the colon & rectum
•Spread by scratching, - hand to mouth
Trichinella
•In humans when eat undercooked infected pork.
•When a person/animal eats contaminated meat containing larvae
•Digestive juices from stomach dissolve capsule releasing the larva
•Larva penetrate into the intestines – mature – mate
•Pass larvae to blood stream where they can move to the muscle fibers
Ascaris
•Ascaris: largest and most common parasites found in humans.
•Eggs are found in the soil, injested & passed to the stomach
•Larvae are carried through the lungs- throat – swallowed
•Intestines- develop to adults.
•Female lay eggs that are passed to feces (200,000/day)
•Cycle takes 2 – 3 months.
Heartworms
•Live in the heart of infected dogs
•Blood vessel which bring blood to the heart
•Male & female worms can live in the heart reproducing babies
which circulate through the body waiting on a mosquito to bite &
suck it up.
•It is then transferred through the mosquito to other dogs
Segmented Worms:
Phylum Annelida
Segmented Worms
• Include Bristle worms,
Earthworms, and
Leeches
• Term annelid means
“tiny rings”
• Bilateral & coleom
with 2 body openings
Characteristic of Annelids
• All Annelids Are
made of segments
• Bodies appear to be
divided into rings
• Segmentations
continue internally
• Each ring is its own
muscle-helps shorten
& lengthens
Parts of the Earthworm
Setae
Gizzard
Brain
Blood Vessel
Crop
Aortic arches
Where do they live?
Everywhere except in frozen soils of
polar regions & dry sand like soils of
the desert
Bristleworms:
• Mostly marine
organisms
• Have distinctive head
with eyes & tentacles
• Each body segment
has a pair of
appendages called
parapodia which are
bristle like structures
Earthworms
• Are nocturnal animal
• Come to surface but
stay close to their
burrows
• Cool moist soil provides
protection during the
day
• Water in the soil is a
source of oxygen that
soaks into the body
through the skin
Earthworms are hermaphrodites
• 2 worms exchange
sperm
• Each worm forms a
capsule for the egg &
sperm
• The eggs are fertilized
in each worms capsule
& slipped off into the
soil
• 2-3 weeks young
emerge
Leeches
• Segmented worms with
flatten bodies & no
bristles
• Found in different
habitats mostly fresh
water
• Have front & rear
suckers
• Parasites that suck
blood
OUCH!!!
• The bite is not painful
b/c the saliva contains a
chemical that acts as an
anesthetic
• Keeps blood from
clotting & increase
blood flow
• Can ingest 2-5 times its
own weight in one meal
• Once fed-it may not
eat again for a year
WOW!