

 Lack
of Tissues
Separates Sponges
from All Other
Animals
 Animals that have
Tissues Exhibit Either
Radial or Bilateral
Symmetry
o Bilateral Animals Have
Heads




The most simple multicellular organisms
Approximately 9,000 member species
Sponges are sessile (stationary)
Important to nutrient cycles in coral reefs

Reproduce sexually and
asexually
o Most sponges are both male
and female. They may play
either role in sexual
reproduction with another
sponge.
o After fertilization, the larva are
released into the water and
float around for a few days
until they stick on a solid
surface.
o Also reproduce through
budding
• When a small piece is broken
off, it will be able to grow into
another sponge

Aquatic, mostly marine
o 99% of all sponges live in the
ocean



A few freshwater species
There are higher numbers of
sponges and sponges species
in the tropics because of the
warmer water
Prefer clear water versus
murky formed by currents
o Murky waters clog their pores







Sponges are asymmetrical. They have an irregular shape.
No “mouth”
No internal organs, muscles, nervous system, or circulatory
system
Their walls are lined with many small pores that allow water to
flow in and out
The structure of a sponge is simple. One end is attached to a
solid such as a rock while the other end, called the osculum, is
open to the environment. Sizes of sponges can range from less
than ½ inch to over 6 feet tall
Sponges are often brightly colored – reds, greens, oranges,
pinks, yellow, lavender
Sponges are able to repair damages to their bodies.



Filter Feeders
Sponges are able to get
microorganisms such as
algae and bacteria for food
through openings.
Some sponges are
carnivorous and use their
spicules to capture small
crustaceans.
Fire Sponge
Touch-me-not Sponge
Giant Barrel Sponge
Harp Sponge

All are aquatic, typically marine
o Some freshwater (Hydras)



Represented by polyps such as
seas anemones/corals and by
medusae such as jellyfish
Both are radially or bilaterally
symmetrical
Uncephalized animal with a
single body opening, the mouth
o Mouth is surrounded by tentacles
studded with microscopic stinging
capsules known as nematocysts
 Diploblastic
– the
body and tentacles
consist of two cell
layers, the
endoderm and
ectoderm
 Between the two cell
layers is the
mesoglea
 The body
encompasses a
single sac-like body
space, the
gastrovascular cavity




Exhibit radial or bilateral
symmetry
All cnidarians have
hydrostatic skeleton to
aid in support and
movement
Polyps are sessile
Medusa swim by floating
and gentle pulsations of
the body wall
Life Cycle and Reproduction

Male and female spawn
freely into the sea, where
fertilization occurs and a
planula develops.
o Cnidarian larva is called
the planula
o A pear-shaped, fully ciliated
animal



The planula settles on and
attached to the
substratum, where it
metamorphoses into a
polyp.
The primary polyp
produces additional polyps
asexually, by budding, and
form a clone or a colony.
Medusae are produced
asexually

Nematocysts, a category
of cnidae, occur in all
Cnidarians
o Organelles that can
discharge threads to
entangle, penetrate, or
poison prey.
 Nematocysts
are
secreted by the Golgi
apparatus of all
cnidarians and only
cnidarians.
 Mechanism
Nematocyst
Discharge
of
o When stimulated, water
rushes into the capsule
o The operculum (cap)
opens and rapidly
launches the filament
o Barbs inject poison into
prey

Stinging jellies contain
nematocysts capable of
penetrating human skin.
o
Hot water immersion and
vinegar are common
treatment

All are carnivorous,
nematocysts and tentacles
are active in prey capture
o Nematocysts entangle and
paralyze prey, contractile cells in
the tentacles cause tentacles to
shorten and draw food towards
the mouth


Considered to be passive
predators, feeding on prey
items that blunder into their
tentacles
The food of most cnidarians
consists of very small
crustaceans
Hydrozoa
Scyphozoa
Cubozoa
Anthozoa



Most are marine
The only class with
freshwater members
Polyp and medusa stage
o Mostly polyps
o Medusa, if present, are usually
small


Polyp stage often colonial
Examples: Freshwater jellies,
freshwater polyps, Portoguese
Man O’ War, Fire corals
Portuguese Man-of-War
 Made up of a colony of organisms
working together
o Some form the tentacles, while others
form feeding bodies, floats, or
reproductive structures


Gets it name from the uppermost
polyp and resembles an old warship
Once a man-of-war captures a meal,
the tentacle brings its prey to one of
several feeding bodies Since the
“individuals” within the colony are
all connected, after a stomach
digests the meal, the nutrients get
spread throughout the colony.
Fire Corals
 Not true corals
 75% of the daily carbon
required by fire corals
are provided by
zooxanthae, a symbiotic
algae
 Human stings are quite
painful; cause welts
and red lesions
 All
are marine
 Large medusa
forms
 Polyp stage
reduced, no
colonies
 Free-swimming
 Examples: Jellies,
sea nettles
Purple-striped Sea Nettle
 Genus of jellyfish
 Exist primarily off the
coast of California in
Monterey Bay
 2.3 feet in diameter
 Sunfish are a main
predator
Lion’s Mane Jellyfish
 The largest recorded
Lion’s mane jellyfish
tentacles that reached
120 feet
 Range of colors including
bright red, dark purple,
tan, and orange
 Stings are seldom fatal
but can cause severe pain
and burns






All are marine
Medusa is cuboidal or boxshaped
Typically live in tropical oceans
Tentacles hang from corners
Polyps reduced or absent
Examples: Box jellies, Sea
wasp






Sea Wasp “Australian Box Jelly”
Lives off the coast of northern
Australia
One of the deadliest organisms on
Earth
Its sting causes an intense pain
and can lead to respiratory failure,
cardiac arrest, and death within
minutess
The amount of poison one sea
wasp is enough to kill 60 people
Sea turtles have defenses against
it and eat cubozoans in great
quantities







All marine, in both
deep and shallow
water
Medusa stage
completely absent
Most are sessile
Many are colonial
Mouth has a pharynx
Gastrovascular cavity
is divided into
sections
Examples: Sea
anemones, true
corals, sea fans
Sea Fan
 Closely related to
coral
 Often purple, ref, or
yellow
 Found primarily in
the shallow, tropical
waters
 Filter feeders
 Large
sea anemone
found in the Gulf of
Mexico
 Closes its tentacles to
capture prey and also
to protect itself
 When disturbed they
will release
bioluminescent
mucous





Corals
Corals live as solitary or colonial
forms and secrete a hard external
shell of calcium carbonate
Each polyp generation builds on the
skeletal remains of earlier
generations, constructing “rocks”
with shapes characteristic of their
species. We call these skeletons
corals.
Coral reefs are to tropical seas what
rain forests are to tropical land
They provide habitat for a wealth of
other species
 Members
of the four classes of the
phylum are known as the “flatworms.”




Approximately 20,000 species
Reproduction mostly sexual
as hermaphrodites
Mostly they feed
on animals and other smaller
life forms.
Platyhelminthes live nearly
everywhere, on land, in both
fresh and marine waters as
well as inside other animals.
Triploblastic
Protostome
Acoelomate
Bilateral
Symmetry
Generally flattened
bodies
Range in size from
1 mm to 20 m
One body opening
Turbellaria
Trematoda
Monogenea
Cestoda







Approximately 4,500 species
Primarily non-parasitic
Mostly free-living flatworms
Mostly marine, but some
freshwater
Either carnivores or
scavengers
Move using a ciliated
epidermis
Range in size from
microscopic to 2 feet
 Planarian
 Freshwater
carnivores
and scavengers
 Distinguished by their
two light sensitive eye
spots
 They are
hermaphroditic but
usually cross-fertilize
Hammerhead Slug
 Large predatory land
flatworm
 Thrive in tropical and
subtropical regions
o Including AL

Predator of
earthworms, slugs,
insect larvae, and are
cannibalistic
o
o
o
o
o
o
Approximately 10,000 species
All parasitic flukes
Most are internal parasites of vertebrates
Most have oral suckers sometimes supplemented by hooks
Outer body lacks cilia
Often have complex life cycles that alternate between sexual and
asexual stages
Chinese Liver Fluke
 Found in Asia including Korea, China,
Taiwan, Vietnam, Japan, and Asian
Russia.
 People become infected when eating
the parasite containing cysts within
infected raw or undercooked fish.
 Infected people will then pass eggs in
their feces or may cough them up.
 Abdominal pain, nausea, and diarrhea
are common symptoms
 Long untreated infections can lead to
cancer.
Schistosoma “Blood Fluke”



Occurs in Africa, South America,
Carribean, the Middle east, and Asia
Infection occurs when your skin
comes in contact with contaminated
freshwater in which certain types of
snails that carry schistosomes are
living.
Symptoms are a rash or itchy skin
within days. You may develop fever,
chills, and muscle aches after a few
months




Approximately 5,000 species
They are found on fishes in
fresh and salt water and in a
wide range of water
temperatures.
Move about freely on the
fish’s body surface feeding
on mucus and epithelial cells
of the skin and gills
This distinguishes them from
other Platyhelminthes
members which are typically
endoparasites
Gyrodactylus elegans
Salmon Fluke
 Lives on the skin of
freshwater fish
 About 1 mm - Can be
seen with a handheld
lens
 Four individuals of the
animal appear to be born
out of the one ova (egg).
Diplozoon paradoxum
 1 cm freshwater fish
parasite
 Do not become
sexually mature until
they meet a member
of their own species
 The two animals form
a permanent union,
joined near the
midsections





Approximately 1,000 species
Tapeworms
A number of tapeworms
include humans in their life
cycles but infection is not
normally a serious health
problem and can be cured
Lives in the host’s intestines
where it gets free food
They have no digestive
systems – absorb nutrients
from their host’s gut
Beef and Pork Tapeworms
 Contracted from undercooked
meat of an infected animal; it is
also possible to contract
tapeworms from an infected
person that prepares your food
 Symptoms: Nausea, Weakness,
Diarrhea, Abdominal pain, Hunger
or loss of appetite, Weight loss,
Vitamin and mineral deficiencies
 Usually treated with oral
medication and passed through a
bowel movement
Roundworms
General Information:
1.
Round, unsegmented bodies
tapered at each end
2.
Pseudocoelomates- body cavity
filled with fluid that distributes
oxygen & nutrients, so they do not
have a circulatory system.
3.
2 body openings- mouth & anus
4.
Size- microscopic to about 1
meter
5.
Bilateral symmetry
6.
Triploblastic
7.
Most are free living
some are parasitic
Cuticle
a.

Thin, tough outer skin may have
spines or scales for protection.

Not easily digested by host

Most molt about 4x during life
Longitudinal muscle
b.

Produces thrashing motion

Creates S- or C-shaped curves

Parasitic, free living or
decomposers

Mouth

May have hooks or suckers for
attaching (parasite)

c. Pharynx- muscular organ
that rhythmically pumps food thru
digestive tract

d. Intestine- long tubular organ
where digestion/absorption occur

e. Rectum/Anus- end of
digestive tract where wastes are
excreted.
Dorsal & Ventral Nerve Cord- run
along upper & lower surface of
body sending nerve impulses to
anterior end.
Nerve ring- simple brain picks up
stimuli from nerve cords.
Amphids – anterior (towards the
head) depressions used for
sensing chemicals in the water
Phasmids – posterior (towards
the tail) depressions used for
sensing chemicals in the water
All roundworms breathe by diffusion of oxygen into
moist skin and carbon dioxide out of moist skin.
Excretory ducts collect
liquid waste
Excretory pores excrete
collected liquid waste
thru skin
Roundworms are dioecious – having separate sexes
a.

Monoecious - Hermaphroditic
Males are usually smaller than females
b.
c.
Most lay eggs that hatch into larva- oviparous
d.
Some give birth to live larva- viviparous
e.
Some create eggs which they retain & hatch inside bodyovoviviparous
f.
Some males may have bursa- flap of skin used to hold
female while transfering sperm
•
May also have copulatory spikes or spicules which are
penis-like
 Egg
 L1-
1st larval stage
 L2- 2nd larval stage
 L3- 3rd larval stage
 L4- 4th larval stage
 Adult
 Molt in between each larval stage to get bigger
 Dauer- after 1st molt larvae may enter this hibernation
stage if overpopulation pheromone is present,
temperature is too high, or no food present.
Free-living soil nematodes
& decomposers- important
as recyclers of necessary
nutrients to soil.
•
1 m2 of mud = 4
million nematodes
Parasitic nematodesCause disease
•
Plants
•
Vertebrates
•
Humans
Vector/mode of transmission- Ingesting
eggs from unwashed hands or
contaminated vegetables
Symptoms- coughing, wheezing,
vomiting, stomach pain, bloody
sputum
Disease- Ascariasis infection
Miscellaneous- largest intestinal
roundworm, most common in
world, usually seen in pigs
Vector/mode of transmission- Ingesting
eggs from unwashed hands or
contaminated vegetables
Symptoms- severe anal itching- when
scratched can cause reinfection
Disease- pinworm infection
Miscellaneous- most common in US,
females detect slowed body
systems at night and come out to
lay eggs around opening to anus,
seen in kids
Vector/mode of transmission- walking
in infected soil
Symptoms- anemic, tired a lot,
hookworm tracts under skin
Disease- hookworm infection
Miscellaneous- feed on blood & tissue,
common in Southeastern U.S.
Vector/mode of transmission- eating
infected meat (usually pork)
Symptoms- diarrhea, cramps, muscle pain
& tenderness
Disease- Trichinosis
Miscellaneous- Adults breed in intestine
larva hatch in intestine, burrow into
skeletal muscle, creating painful
cysts.
Vector/mode of transmissioninfected mosquitoes
Symptoms- swelling of lymph vessels
causes swelling of lower
extremities
Disease- Elephantiasis
Miscellaneous- no cure, takes many
years to develop, occurs
mostly in tropics, can lead to
secondary infections, filarial
worms in U.S. cause
heartworms in dogs
Vector/mode of transmission- infected Cyclops in
contaminated drinking water
Symptoms- worm grows under skin & head creates a
painful, burning ulcer
Disease- Guinea Worm infection
Miscellaneous- female reaches 3 ft, common in
tropics, worm must be wound out of skin with
stick, if worm breaks can cause secondary
infections
The Segmented Worms
A.
“Annelid” means tiny rings
B.
Can grow from a few inches to
22 feet
C.
Coelomates --- True body cavity
with space for internal organs
D.
Body is cylindrical and shows
metameric segmentation
E.
Bilateral symmetry
F.
Closed circulatory system
G.
Classified based on amount of
hair-like setae.
Classes of Annelids
A. CLASS OLIGOCHAETA
1. Oligo = few chaeta = hairs
2. Earthworms with a few setae (hair-like
structures)
3. Terrestrial and Aquatic
a.
Prostomium- 1st body segment,
overlaps mouth
b.
Pygidium- last body segment,
overlaps anus
c.
Cuticle- tough outer covering for
protection
d.
Muscles- 2 sets create wave-like
motion; longitudinal & circular
e.
Clitellum- band-like structure at
anterior end, used in sexual
reproduction
f.
Setae- short bristles on ventral
surface that help them cling to
burrows, movement/anchoring
a.
Nocturnal- Feed at night on leaf litter and soil
(scavengers/decomposers)
b.
Mouth- opening to digestive tract
c.
Pharynx- acts like pump, pulling food into
mouth.
d.
Esophagus- tube that leads to crop
e.
Crop- storage chamber for food.
f.
Gizzard- grinds food before it enters intestine.
g.
Intestine- absorbs nutrients from food-
h.
Anus- solid wastes excreted here
i.
Castings- “worm feces”
Crop
Pharynx
Esophagus
Ventral Nerve Cord
Gizzard
Intestine
a.
Nephridia- kidney-like organ
that consists of tubes for
removing liquid waste. Two
per segment
b.
Nephridiopores- pores in skin
that excrete liquid waste.
a.
Cerebral ganglion - bi-lobed simple brain over pharynx
b.
Ventral Nerve Cord- runs length of body on ventral surface
c.
Ganglia- mass of nerves along ventral nerve cord.
d.
Sensitive to touch, light, temp., moisture
a.
b.
Terrestrial- Gas exchange
occurs thru diffusion thru
moist skin
Aquatic- frilly gills
a.
Closed Circulatory Systemblood is enclosed in blood
vessels
b.
5 Pairs of Aortic Archesenlarged blood vessels that
pump blood thru body
c.
Dorsal blood vessel- carries
blood to anterior end
d.
Ventral blood vessel- carries
blood to posterior end
a.
Monoecious- hermaphrodites
b.
Do not self-fertilize
c.
Worms line up with anterior ends away from each other.
d.
Sperm released from seminal vesicles of one worm and is
passed along a body groove to the seminal receptacles
(receivers) of the other worm.
CLASS POLYCHAETA
1.
Poly = many
chaeta= hairs
2.
Marine worms with many setae
3.
Largest class of annelids
4.
Live in coral reefs, ocean floor,
crevices, etc
5. Have parapodia which look like
paddles along body used for
movement
6. Have sensory tentacles called cirri
around mouth.
7. Dioecious
8. EX: clamworms, sandworms
CLASS HIRUDINEA
1.
Leeches with no setae
2.
Most freshwater, some
marine & terrestrial
3.
Ectoparasites that feed on
body fluid of host
4.
Flattened, segmented
5.
34 segments
6.
Monoecious- clitellum only
present in spring
Common
Characteristics
• Soft bodies
usually protected
by shell.
• True coelom
Usually have 3 body regions:
a. Head/foot- locomotion &
retraction of body into
shell.
b. Mantle- thin skin layer
covering visceral mass;
secretes shell.
c. Visceral mass- organs for
digestion, excretion,
circulation, reproduction
Kingdom Animalia
Phylum Mollusca
 Class
slugs
Gastropoda- snails,
 Class
Bivalvia- clams,
oysters, mussels
 Class
Cephalopoda- squid,
octopus
Class Gastropoda
1. Snails, slugs
2. Marine, freshwater,
terrestrial
3. Largest & most varied class
4. Some have shell- univalves (one shell)
Shell
Apex
Eyespots
Pneumostome
Tentacle
Operculum
Mouth
Foot
Head/anterior
Locomotion
1. Wave-like contractions of muscular foot.
2. Lay down layer of mucus (terrestrial)
Digestion/Feeding
1. Have radula- tongue-like organ
with tooth-like structures for
scraping food.
2. Mostly herbivores (algae); some
predators
3. Mouth, pharynx, esophagus,
stomach, intestine, anus.
4. Salivary & digestive glands help
breakdown food
Respiratory System
1. Gills- aquatic
2. Lungs/diffusion- terrestrial
3. Pneumostome- opening to
allow oxygen to enter body.
1. Open circulatory systemblood leaves short
vessels and bathes
tissues directly in blood.
2. Pulmonary veinconducts oxygen from
gills to heart via blood.
3. Heart- pumps blood rich
in oxygen to rest of
body thru aorta.
4. Aorta- dumps blood into
spaces around organs
1.
Most are monoecious.
3. Eggs are fertilized
internally & layed as
sticky mass.
4. Some marine gastropods
are dioecious.
Economic/Environmental Significance
1. Source of food (escargot) & part of food chain
2. Slugs destroy gardens/crops
3. Hosts for parasites of man (flukes)
4. Shells can be used as a source of jewelry
5. Venom can be used in medicine



The incredibly toxic venom of the cone
snail has to be strong enough to
paralyze instantly.
The most venomous of the 500 known
cone snail species. Their venom, a
complex concoction of hundreds of
different toxins.
Some proteins in their venom have
enormous potential as pain-killing
drugs. These proteins target specific
human pain receptors and can be up
to 10,000 times more potent than
morphine.
Class Bivalvia
1. Clams, oysters, mussels, scallops.
2. All marine or freshwater
3. Second largest class
4. All have 2 shells
1.
Clams/musselsmuscular foot for
burrowing
2.
Oysters- adults are
sessile
3. Scallops- “clap” shell
1. Filter feeders- algae, larvae,
small particles
2. Food/water enter incurrent
siphon.
3. Food swept into mouth by 2
pairs of palps
4. Esophagus, stomach,
intestine, anus
5. feces/excess water leave
thru excurrent siphon.
1.
Oxygenated water enters
incurrent siphon.
2.
Gills have tubes where
water & blood are close
together. Gases
exchange by diffusion
across the membrane.
3. Deoxygenated water
leaves thru excurrent
siphon.
1. Open
2. Heart and short
vessels similar to
gastropods.
1. Most are dioeciousexternal fertilization
2. Sperm leave thru
excurrent siphon
3. Sperm brought in thru
incurrent siphon of
female.
Economic/Environmental Significance
1. Source of food/part of food chain
2. Filter/clean water of harmful pollutants
(algae)- can cause sickness if red tide algae
are eaten.
3. Form pearls/jewelry
4. Mother of pearl buttons made from
shells
Class
Cephalopoda
1. Squid, octopus,
nautilus, cuttlefish
2. All marine
3. Most complex mollusk
4. No external shell,
have internal support
a. Squid- have internal
chitinous structure
called pen
b. Cuttlefish- have cuttlebone.
Can be used as calcium
supplement for birds.
c. Chambered nautilus - has
true shell
d. Octopus- has no shell
Dorsal
Locomotion
1. All cephalopods can
move by jet propulsion-
forcefully expelling water from siphons on head.
2. Octopus crawl with arms.
3. Squid & cuttlefish have posterior fins for steering/movement.
Digestion/Feeding
1. Have arms with suction cups to capture/hold prey.
2. Sharp beak for tearing into prey.
3. Radula for drilling holes in shells.
4. Use extracellular digestion- secrete enzymes that breaks down food before enters
mouth.
5. Most nocturnal- eat
crustaceans, fish,
other mollusks, etc.
Radula
Beak
Respiratory System

Gills in mantle cavity
Circulatory
System
1.
Closed- blood
enclosed in blood
vessels.
2.
Have hemocyanincopper rich blood
(blue)
1.
Dioecious
2.
During the mating process the sperm from the males
are placed inside of this sac where they will fertilize
her eggs.
o
3.
When you look closely at the arms of a squid, you will notice
the male has one that is shorter than the rest. This is what is
used to place the sperm into the female.
She will distribute them in hidden areas of the water
including under rocks or in various holes and crevices
she can find. The female squid don’t wait around for
them to hatch, they leave after depositing them.
Dorsal
Anterior
Posterior
Ventral
Economic/Environmental Significance
1. Food source- calamari, octopus
2. Bait for commercial fishermen
3. Can be pests in oyster beds- eating up all profit!
4. Cephalotoxin may be used for medicine/research
•The Giant Squid
•50 feet long & weigh almost 1 ton
•Eats fish & other squid and has been known to
eat sperm whale calves