Transcript Ch 6 Protozoans and Invertebrates

Protozoans and Major
Invertebrate groups
Single celled animals, “tissue”
organisms, and the animals
without backbones
Characteristics
• Protozoans-single celled, eukaryotic,
heterotrophic (nonphotosynthetic),
microscopic; asexual and sexual
reproduction.
• Multicellular Animals- many cells, tissue
level and system level organisms;
heterotrophic; shape may be
asymmetrical, radial or bilateral; asexual
and sexual reproduction.
Globigerina
The "shell" is
composed by a
number of spherical
chambers. Very
common and
abundant in pelagic
plankton, even at the
very deep.
Kingdom Protista
Phylum
Sarcomastigophora
Order Foraminiferida
Shells of Calcium carbonate
• The possession of photosynthetic
symbionts by marine protozoa may make
them important primary producers as well as
being consumers.
• Thus the radiolarian protozoa, ACTINOPOD
amoeba which live suspended in the
euphotic* zone (that where there is enough
light for photosynthesis) of warm seas,
"farm" photosynthetic dinoflagellates* as
symbionts in their cytoplasm* while also
feeding phagotrophically* on other
planktonic organisms.
• The siliceous skeletons of these organisms
are objects of immense beauty; they sink to
the sea bed forming the "radiolarian ooze".
Radiolarians
Radiolarians are single-celled
protistan marine organisms that
distinguish themselves with their
unique and intricately detailed
glass-like exoskeletons, silica.
Skeleton commonly known as
tests. Most contain many spines
and holes that regulate a
network of pseudopods useful
in gathering food. Dead
radiolarians accumulate in the
ocean floor.
Tintinnid
Note the tintinnid ciliate
lower left that has been
suspension feeding on
phytoplankton, visible in
food vacuoles.
Ciliates
Ciliates are microscopic
unicellular organisms,
generally found in the
plankton of rivers, lakes,
seas and oceans. They are
characterized by having
hairy structures called
cilia. These cilia can
surround all the cell or part
of it. They are used both
for moving and for creating
currents to carry food to
their mouth.
How are they and what is
their size?
Their shape can be
spherical, ellipsoidal,
conic or cylindrical
and their size can
vary between 10 and
200 µm. Some of
them build a
transparent shell
around the cell called
lorica (in tintinnida),
while other are naked
ciliates.
Characteristics
• Protozoans-single celled, eukaryotic,
heterotrophic (nonphotosynthetic),
microscopic; asexual and sexual reproduction.
• Multicellular Animals- many cells,
tissue level and system level organisms;
heterotrophic; shape may be
asymmetrical, radial or bilateral;
asexual and sexual reproduction.
Types of symmetry
• asymmetrical
• radially symmetrical
• bilaterally symmetrical
Porifera: The Pore animals
Porifera: “pre-tissue-level”
animal
Sponges are among the most
abundant and widely
distributed marine animals. A
sponge can either be a single
animal or a colony of
animals. They are incapable of
locomotion and they attach
themselves to rocks. The
living "tissue" is a soft, dark,
slimy material that covers a
soft, flexible skeleton. The
skeleton is what is left after the
softer tissue has been cleaned
off.
Cnidaria: jellyfish,sea
anemones, corals, hydroids
Although cnidarians vary
greatly in appearance,
they do have common
characteristics that
separate them from other
groups. A common
characteristic that has
given this group its name,
are its stinging cells
(cnidoblasts).
Polyp and/or Medusa
Cnidocysts (nematocysts)
Stinging cells can even be
used for defense. However,
most stinging cells are of
insignificant strength to cause
discomfort to man, but there
are a few exceptions, like the
lion´s mane jellyfish. A few
specie can be very venomous.
In Swedish waters only the
stinging jellyfish can cause
discomfort.
Examples of Representatives
When touched they can
discharge a barbed
thread that is connected
to a venom sac.
Cnidarians use their
stinging cells to
incapacitate their prey.
Large cnidarians like
jellyfish and anemones
are predators that can
attack large prey.
Moon jelly
Black Sea Nettle
Portuguese man-o-war
This colony of
animals is found
in the warmer
regions of the
Atlantic and Gulf
can cause very
painful injuries.
Box jellyfish
seawasp
Along the beaches of Australia and
Hawaii, signs are often posted
warning for a special type of
cnidarian, the box jellyfish.
Injuries from box jellyfish can be
lethal if medical attention is not
acquired in time. Symptoms of a
sting include stinging, burning,
redness, swelling of lymph nodes
and in cases of severe reactions
may result in difficulty with
breathing, symptoms of shock and
cardiac arrest.
Ctenophora
The rainbow colors on
ctenophores are not
bioluminescence. They are
merely diffraction acting on
the ambient light. This
shallow-dwelling species,
Beroe forskalii, produces a
bright luminescent display
when disturbed. (Approx size
10 cm).
Ctenophore, Pleurobranchia
• tentacles armed with
colloblasts capture
food
• four external bands
of cilia called ctenes
that provide
propulsion
Platyhelminthes: the flatworms
• Endoparasitic and
ectoparasitic
• Free-living
• Three groups:
1. flukes
2. tapeworms
3. turbellarians
Nemertina: benthic ribbon
or bootlace worm
This is a Ribbon Worm, or
Bootlace Worm. They can
grow very long and can
change shape from being a
short, fat worm to being an
extremely long thin worm.
Unlike most worms, it does
not have a mouth at the
end of its body, but has a
long proboscis which can
shoot out from a pore
about a quarter of the way
down the body.
Gastrotricha
Usually less than 1
mm, these worms
they often go
unnoticed. They live
in the sand and mud
deposits in shallow
marine water and
feed on detritus,
diatoms, and other
small animals
Nematoda: the round worms
• Round worms are
separately sexed
(males and females)
• Probably the most
abundant group of
organisms on Earth.
• Free-living and
parasitic
Mollusks
Soft-bodied animals, having a
muscular foot, mantle that
may produce a shell. Shells
may be internal or external
and vary in number of pieces
(valves or plates). Most
exhibit cephalization and
many have a radula, a rasping
tonguelike organ.
www.oceanlight.com/
html/squid.html
Chiton
Early Americans
ate chitons in
times of extreme
hunger.
Known for their 8
plates that appear
as a ribbon shell
when animal
tissue dies away.
Molluscan parts…
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•
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•
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heart
intestine
radula
shell
foot
stomach
mouth
eyes on stalks
Chambered nautilus
The chambered
nautilus is a
cephalopod
with a beautiful
external shell
Squid or Cuttlefish?
Cuttlefish
The cuttlefish looks
like a flattened squid
and has an internal
skeleton-the cuttle
bone (below) that is
often used as a
supplement for
birds.
Scallop
Bivalve
Able to move by a
“clapping” motion
Octopus
• shy, timid and not
aggressive
• average size is about
three feet from head to
end of arms
• mate one time, female
cares for her eggs
without eating, and she
dies as the eggs hatch
Giant Octopus
The octopus has eight
tentacles that sometimes
stretch 4.8 m across in a 45
kg specimen. The octopus is
a mollusk that is related to
the squid, oyster, clam and
snail. The giant Pacific
octopus is the major species
on the west coast and also
the world's largest. It is illegal
to use jigs, gaffs, spears,
rakes or any other sharppointed instrument to take
octopus.
Giant squid
Estimated 100 feet
long and weighing 2
tons
Chaetognatha
• Arrowworms are
torpedo-shaped
planktonic carnivores.
• The tiny reflection in
wet beach sand are
probably the
chaetognath, Sagitta.
Annelids
the segmented worms
This phylum includes
earthworms, leeches
and marine worms,
the Polychaetes.
Many are tubedwelling and have
filtering structures
resembling feathers.
Arthropoda: the jointed
legs, segmented bodied
animals
Widely distributed on the
planet earth, these
animals have
exoskeletons composed
of chitin. Their size varies
from microscopic
copepods and other
marine crustaceans to
crabs several feet across.
Shrimp, crab and lobster
Blue crab
Female and male crab
Growth rate
Must molt to grow; females and males sexually
mature at 100 and 150 mm, respectively (2-3 yr);
males reach legal size (165 mm) at 3-4 yr; females
seldom reach legal size.
Limulus-horseshoe crab
These animals have aqua
blue blood. Although
horseshoe crabs look
dangerous, they are not.
And they are really not
crabs at all; they are
distant relatives of the
spider.
Gender: Male or Female?
Several distinct variations between males and females occur in
horseshoe crabs. Upon reaching maturity at 9-10 years old, the
female horseshoe crab will molt one or two more times unlike
the male crab that stops molting. As a result, the female crab is
considerably larger than the male. Also, the mature male
horseshoe crab will develop a modified first pair of walking legs.
The new legs (pedipalps) have a hooklike structure that
resembles a boxing glove. The male horseshoe crab uses the
modified legs to clasp onto the shell of the female during
spawning. Prior to reaching maturity males and females are
identified by the shape of their genital pores. The pores can be
found behind the first gill cover at the base of the first pair of
book gills. On a male, the genital pores are firm pointed
structures and white in color. Differing from the male, the
females genital pores are broad convex structures similar in
appearance to small bumps.
Sexing the Horseshoe crab
Male
female
“blue blood”?
Why is the Horseshoe Crab the original
“blue blood”?
A horseshoe crab’s blood has a blue to
blue-green color when exposed to the
air. The blood is blue because it
contains a copper-based respiratory
pigment called hemocyanin.
HORSESHOE CRAB BLOOD
The blood of the horseshoe crab is not only unique
but it provides a valuable medical product critical to
maintaining the safety of many drugs and devices
used in medical care. A protein in the blood called
Limulus Amebocyte Lysate (LAL) is used by
pharmaceutical and medical device manufacturers
to test their products for the presence of
endotoxins, bacterial substances that can cause
fevers and even be fatal to humans.
OTHER MEDICAL BENEFITS
Horseshoe crabs have also been proven to benefit cancer
research. Endotoxins are known to inhibit the growth of cancer
cells. Therefore, the ability of the LAL test to detect cancer cells
may lead to a new type of cancer therapy using endotoxins.
Another substance found in horseshoe crab blood may have
the potential for diagnosing leukemia. This substance reacts
with red and white human blood cells, including cancerous
white blood cells in leukemia patients. Furthermore, a New
Jersey Sea Grant project has recently discovered a rare protein
in horseshoe crab blood that traces and binds with vitamin B12.
These findings led to the development of an accurate, costefficient testing kit for detecting vitamin B12-related
deficiencies and diseases, which may include pernicious
anemia, gastric and intestinal damage, and even mental
disorders.
Barnacles
Copepods
Although most of the approximately 8,500 species of copepods
are marine, some live in freshwater lakes and ponds. One of
the most important and abundant components of aquatic food
chains, copepods feed on unicellular phytoplankton
(photosynthesizing protists). Lacking a carapace, copepods
have cylindrical, tapering bodies with forked tails. In contrast to
other crustaceans, copepods lack gills and abdominal
appendages. The female copepod shown in the image
(appropriately named Cyclops) carries eggs inside of two
attached egg sacs.
Mysid
These small organisms show a very
strong seasonal pattern with highest
abundances in the summer and fall
of the year when they reach mean
densities of 300-700 per sample
and peak at over 2000 in a single
sample, but may be completely
absent from samples during other
times of the year. Their value is a
food resource for fisheries species.
Mysids are highly motile and can
migrate vertically although they are
primarily a bottom dwelling group
Euphausiid
• Euphausiid's are harvested mainly
as a feed supplement for both fish
farms (gives salmon their "pink"
color) and humans consume them.
• Swimming appendages are too
small to enable them to swim
effectively against the currents, so
they are common and widespread
along the coast.
• Krill undergo a daily "diurnal" cycle,
where they spend the daylight
hours in the twilight depths of the
ocean (100 meters or 300 feet), and
during the night or cloudy days they
come closer to the surface.
Intertidal at over 100 meters
subtidal depth to 60 meters.
Brine shrimp
Brine shrimp are
branchiopod crustaceans
that live in waters with
high salt contents (like
Death Valley, Great Salt
Lake, etc.). They often
produce resistant eggs as
an adaptation to drying in
temporary pools. When
the rains come and the
eggs are rehydrated,
they hatch into tiny brine
shrimp. It is these eggs
that are sold in dehydrated
form for aquarium fish
food as well as for
culturing so-called "sea
monkeys".
The Echinoderms
All members of this
phylum live in a
marine environment.
Representatives
include sea stars,
brittle stars, sea
urchins and sand
dollars, sea
cucumbers, feather
stars and sea lilies.
Brittle star
Brittle stars have
delicate arms that
quickly regenerate
from the central disk
when broken.
Sea Urchin
Habitat
Rocky substrates,
especially ledges and
crevices; locate near or in
giant or bull kelp beds
and other brown algae in
areas of moderate to swift
currents; larvae drift and
feed in plankton; juveniles
settle near kelp beds,
often associate with
aggregations of adults,
remain under adult spines
until they reach 40 mm.
The Invertebrate Chordates
Chordates exhibit at
sometime their life history:
– notochord (cartilage),
– dorsal nerve cord, and
– paired gill slits.
Common reps considered
invertebrate chordates
include the tunicates
(lancelets) and sea
squirts)
TUNICATA
(Urochordata
CEPHALOCHORDATA
(Lancelets)
Lancelet
Invertebrate food from the sea
Name the phyla
represented
1.
2.
3.
4.
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