Marine Protozoans
Sub kingdom:
protozoa of Kingdom Protista 31,250 species in 7
phyla Features:
unicellular,
free
living or parasitic,
mostly
solitary though some colonial (ciliate and flagellates)
Marine Protozoans
move
by
pseudopodia,
flagella,
or
cilia,
some
amoeba with tests,or shells,
ciliates
possess a mouth (cystostome) and nuclei of two sizes,
reproduction
mainly asexual,
sexual
reproduction in some groups.
Marine Protozoans
Special
marine ones... Subphylum Sarcodina (including
amoeba) produce so-called pseudopodia-flowing extensions of the cell which can extend
one or more at a time (depending what species) .
Marine Protozoans
Amoeboid
marine protozoans, the Foraminiferans
and Radiolarians build cases around themselves. Forams
secrete a calcium (chalky) carbonate shell or test, which resembles a microscopic
snail shell.
Foraminiferans
Foraminifera, or 'forams' as they
are often called, are small marine creatures that build a delicate house
(called 'test') from chalk. Although they resemble molluscs
they are in fact single cellular protists, but they
can be quite large for organisms with only one cell. The largest forams are more than 10 centimetres
wide. The pyramids of Egypt are made of stone cantaining
these creatures. The forams in this gallery are up to
2mm. and were collected from beaches around the world.
Marine Protozoans
Their pseudopod extend
through pores to form a network used to trap diatoms and other minute organisms
suspended in water.
Most live on
the bottom either free or attached.
The covering
of forams is potmarked with
numerous holes which the pseudopods extend through to
capture smaller ciliates and detritus.
Marine Protozoans
As these die,
they sink to the ocean floor to form ooze which makes up thousands of square
miles of the ocean floor. (white cliffs of Dover are foram tests).
Marine Protozoans
Scientists
use the fossil tests to measure variations in the worlds
temperatures as the structure and sizes of the tests change with water
temperature changes.
Forams
living in cold water have fewer pores than those in warm water.
Marine Protozoans
Marine Protozoans
They are
among the largest protozoans with some reaching 100mm
but usually .5 to 1.0 mm The tests are various
shapes--oval, tubular, branched, spiral, etc.
Most shells
are multi chambered consisting of a series of successively larger chambers
which are separated internally with pores or canals connecting them.
Marine Protozoans
The cytoplasm
is found in all the chambers and is continuous through pores connecting the
chambers.
By passing
though the pores of the test, the cytoplasm forms a layer (ectoplasm) over the
test which connects to the endoplasm through the pores. As the animal grows it
adds successive chambers to the initial chamber.
Marine Protozoans
They capture
their prey by means of their pseudopodal network
which exhibits active streaming movements.
They are
found in marine and brackish water and only a few in fresh.
A few are
pelagic or sessile but most are creeping bottom dwellers (benthonic).
Marine Protozoans
A third of
the ocean bottom is covered with Globigerina ooze, made mainly of the
accumulation of the tests of this common foram. (usually in water under 4000 m deep because tests dissolve in
the high concentration of CO2 in deep water.)
Good fossils
are important in detecting oil bearing strata.
Marine Protozoans
Radiolaria
(Subclass) Radiolarians form a glass like test
composed of silica which is studded with long transparent spines to increase
buoyancy and ward off predators.
Typical
shells are spheric with radiating spines though the
structure varies...thin needlelike pseudopod capture
food.
Marine Protozoans
The
radiolarians also form ooze, though radiolarian ooze and is usually found
deeper being able to resist more pressure than the calcium carbonate foram tests.
Marine Protozoans
Ciliates are
some of the protozoans that use cilia for locomotion.
..creeping over the bottom, living in gills, attached
etc.
The Tintinnids build their own quarters that drift in the
water.
Marine Protozoans
Reproduction is
usually asexual binary fission whereby each effort results in
two identical daughter cell (MITOSIS).
This occurs
when conditions are favorable...warm, lots of food etc.,.
but sexual reproduction can occur in some when adverse
conditions (drying up) occur as a survival method.
Marine Protozoans
The forams have alternation between sexual and asexual
generations, having asexual reproduction to produce many organisms which
secrete shells around themselves and when mature, they produce identical
gametes which are liberated into the sea and fuse in pairs to produce
individuals which in turn secrete a shell grow to maturity and repeat the
cycle.
Marine Protozoans
Life cycles
are known for a few foraminiferans.
They have two
phases, one asexual and the other sexual.
They are also
dimorphic, having two types of individuals in each species, based mainly upon
the size of the initial chamber (proloculm) of the
test.
Marine Protozoans
Ecology
Its complex as it would be for organisms found in every environment.
They occur
commonly in plankton...benthic communities, marine depths (13,000 ft for a foram) and since many protozoans
exploit bacteria as a food source, they form part of the decomposer food web in
nature.
Marine Protozoans
It is thought
that they stimulate the rate of decomposition by bacteria by grazing on
bacteria and keeping the bacteria community in a state of physiological youth
and hence at the optimum level of efficiency.
Ciliates can
cause illness in some organisms.
Marine Protozoans
Invertebrates
Early
invertebrate records are scarce because of the lack of fossil evidence until
about 570 million years ago (Cambium) when organisms with external skeletons
appeared.
All
phyla that had hard outer parts existed 530 million years ago and many soft bodied
animals belonging to modern phyla of worms appeared as well.
Invertebrates
During the
jellyfish-worm stage of animal evolution, the various basic designs of animal
bodies evolved. First came the jellyfish, a blind sac
with only two layers of cells and a single opening serving as both mouth and
anus.
Invertebrates
They have
radial symmetry, meaning they have no front or hind end which is adaptive to
only two types of habitats...floating on the surface of the sea or attached in an
immobile position on the ocean floor.
Great masses
of jellyfish cover wide stretches of the ocean and corals and sea anemones line
tide pools in warm waters.
Invertebrates
The jellyfish
phyla are dominant in these habitats and while their basic body plan adapts
them admirably to certain ecological niches, it severely limits their options
for colonizing others.
This body
plan was also successful in flatworms but nowhere reached the dominance of the
body plan of a tube within a tube design.
Invertebrates
There are
three plans, bilateral symmetry, a diversity of tissues and organs, spaces or
body cavities (coelom) filled with fluid and a fourth
modification is characterized by radial symmetry found in sea stars etc.
Invertebrates
What do
crabs, sea urchins, worms, corals all have in common? they
have NO backbone and are all invertebrates. Over 95% of all known animals are
invertebrates. Their forms range from the microscopic amoeba to giant squids 59
ft. long, inhabit all regions of the world and all have a marine
representative.
Invertebrates
SPONGES
Phylum Porifera..(pore-bearing).
5000 species of 790 genera...worldwide distribution, fresh
and marine. (120 species in Keys!) Size
microscopic to 2m
Sponges..animals with many
pores, without definite form of symmetry, and do not contain organs or true
tissues. They are all sessile.
Invertebrates
Invertebrates
The humble
bath sponge, used for centuries particularly in the Mediterranean region were originally
thought of as plants but are now considered animals (only in 1765)(even its own
subkingdom ..Parazoa) They
probably originated from flagellated protozoans or
primitive metazoans. They are the simplest of multicellular
marine animals.
Porifera
The humble
bath sponge, used for centuries particularly in the Mediterranean region were
originally thought of as plants but are now considered animals (only in
1765)(even its own subkingdom ..Parazoa) They probably originated from flagellated protozoans or primitive metazoans. They are the simplest of
multicellular marine animals.
Porifera
Their colors
though are beautiful, Orange, yellow, green, purple, violet or scarlet or rich
brown and have survived millions of years without even moving.
Porifera
Size
range from micros. to 2m, form
thin incrustation on hard surfaces to which they attach, others are massive
tubular, branching, urn- or cup- or fan- shaped (amorphous).. Colors range from
drab to brightly colored.
Porifera
The sponges single purpose in life is to pass water through
itself, the water yielding food and oxygen, minerals, and carrying away waste
products. The sponges are unchanged since they evolved and were ancient 300
million years ago and appear to be natures orphans
Porifera
They are so
poorly organized that they are not even included in the direct line of animal
evolution.
Porifera
Rachel Carson
wrote that "nature seems to have gone back and made a fresh start with
other materials" with no evidence of any relationship between them and
coelenterates, leaving sponges in an evolutionary blind alley.
Porifera
Structure.. most are similar in structure,
simple body wall containing cells and connective tissues and cell types like amoebocytes which wander through the inner tissue secreting
and enlarging the skeletal spicules and laying down spongin threads.
Porifera
Most have a
skeleton of spongin, elastic, but resistant fibers of
protein which may be the only means of support but can be found together with spicules.
Sponges, like
all animals, possess some sort of a skeleton that gives their bodies shape.
As a whole, poriferans have diverse skeletal elements including
calcareous laminae, organic filaments, and siliceous
and calcareous spicules. The skeletons of each of the
major poriferan groups are distinctive and have been
used to reconstruct their
evolutionary relationships.
Spicules
come in an array of beautiful shapes, as seen in the SEM images to the left.
These images
were obtained using UCMP's Enivronmental Scanning Electron Microscope.
Spicules are often categorized by size, the larger
being megascleres and the smaller microscleres.
Some spicules are formed of the mineralized
substances calcium carbonate and silica, while others are made of an organic
substance called spongin.
Spongin
skeletons were and are used as scrubbers in bathtubs, though they are fairly
expensive. The ubiquitous bathtub accessory called a lufa
is NOT a sponge, but a plant. The mineralized forms are considerably more hard and are not as frequently used for commercial
purposes.
Porifera
The internal
skeleton can be made of hard rod or star shaped calcareous or siliceous spicules, the shapes genetically determined for each
sponge, and/or the meshwork of protein fibers called spongin
(bath sponge) which is similar to silk and the horns of many animals.
Porifera
Sponges are
filter feeders straining off bacteria and fine detritus from the water. O2 and
dissolved organic matter are also absorbed and waste materials are carried
away. Water is pumped inward through small pore cells into the inner chambers
lined by flagellate cells called collar cells.
Porifera
They ingest
the food particles and water is expelled through the sponges
surface through the osculum.
Reproduction
can occur asexually by budding off new materials, by fragmentation in which
parts grow into new sponges, and in sexual reproduction, eggs from amoebocytes and sperm from collar cells (or amoebocytes) usually at different times within the
individual.
Porifera
Sperm is shed
into the water but eggs stay in the sponge and is fertilized there. This is
called spawning. A larva (amphiblastula) may be
produced, swim for a few days and settle changing into colonies. Some Antarctic
sponges (mature) have not grown in over 10 years.
Porifera
Classification...because
they adapt to their environment their shape is of no help to identify them so
they are classified by their skeletons, "lime sponges, glass sponges, and
fibrous or horny skeletons.
Porifera
Ecology.
Sponges live on a firm substratum, vertical range from intertidal
to 27,000 ft (one fresh) and the intertidal are
seldom exposed to air for any time.
They are
eaten by sea slugs (nudibranches) ,
chitins, sea stars, turtles, some tropical fish
Porifera
Usually more
than half the exposed species are toxic to fish. The toxins not only prevent
predation but keep the surface of the sponge clean of animal larva and plant
spores from settling on them and may prevent neighboring invertebrates from
overgrowing and smothering them.
Porifera
Sponges
contain antibiotic substances, pigments, chemicals like steroids, toxins, anti-inflammatory,
and anti-arthritis compounds. Boring sponges (Cliona)
weakens oyster shells, and damage and weaken tropical stony corals excavating
chambers by chemical and mechanical methods.
Porifera
On reefs some
weaken, while some bind skeletons together, some protect undersurface of coral
from attacks by boring organisms and are most successful under low light. Other..sulfur sponge is able to
dissolve seashells into calcium and accounts for conversion of shells to sand
on the ocean
Porifera
Loggerhead
sponge, shaped like barrels, host up to 12,000 pistol shrimps and other
creatures. The sea orange wraps itself around a hermit crab shell,
obtaining transport in exchange for the camouflage and Neptunes
Cup grows out of the sea floor in the shape of a goblet.
Cnidaria
Phylum Cnidaria .
9400 species...4 classes..
mainly
marine
free
swimming and bottom dwelling
microscopic
to several meters
Cnidaria
radially
symmetrical with
cells
arranged into tissues
posses
tentacles and stinging cells
2 layer body
wall with non-living jelly-like wall containing elastic
fibers
to allow movements in between with digestive cavity
no
anus,
Hydrozoa,
Scyphozoa, Cubozoa, and Anthozoa
Cnidaria
2 distinct life
history phases, free swimming Medusa and sedimentary polyp.
Cnidaria
Class Hydrozoa..most
primitive Many consist of feathery or bushy colonies of tiny polyps.
They are
attached to pilings, seaweed, shells and other surfaces. The Siphonophores are hydrozoans in drifting colonies.
Some polyps
form floats, others form long tentacles to capture prey. Portuguese man-of-war
is an example.
Cnidaria
(Hydroids)
Cnidaria
(Physalia
)
Cnidaria
Class Scyphozoa...jelly fish
has digestive system is a set of radiating canals linking the central portion
to a peripheral ring. Some mesogleas can expel heavy
chemical ions and replace them with lighter ones to adjust buoyancy.
Cnidaria
Cubozoans
In
the class Cubozoa, which includes box jellies and sea
wasps
The
medusa is box-shaped and has complex eyes
Cnidaria
Class Anthozoa Corals and
sea anemones only exist as polyps.
The sea
anemones always bear more than eight tentacles .
Some burrow
in mud but most dwell on a hard substratum, cemented there by secretions from a
well differentiated disk.
Cnidaria
Subclass
Zoantharia are hard corals whose polyps are encased in a rigid calcium
carbonate skeleton. Most hard corals live in colonies which are composed of
vast numbers of small polyps (about 5mm) but can be larger in solitary forms .
Cnidaria
Most are
subtropical or tropical in distribution. In colonial forms, the polyps are
interconnected laterally forming a living sheet overlying the skeleton.
Corals
exhibit a great diversity in growth forms, ranging from delicately branching
species to those whose massive skeletal deposits form the building blocks of
the reef.
Cnidaria
On type, Meandrrina, the polyps are arranged
continuously in rows, resulting in production of a skeleton with longitudinal fissures,
a feature which accounts for its name, brain coral.
Cnidaria
There is an
order related to the hard corals without a skeleton that are anemones which can
cover rock faces. The black or thorny corals form a slender, plant-like
colonies arranged around a horny axial skeleton and possess numerous thorns
Cnidaria
Octocorallian
corals have eight featherlike tentacles and an internal skeleton like
structure. These include the horny corals, sea whips and fans and red coral.
Most of these have ancestral rod composed of organic material around which is
draped the coenenchyme and polyps, the former
containing spicules which impart a vivid coloration
and form the spines of the red coral which is used in jewelry.
Cnidaria
To trap prey,
cnidarians normally employ stinging cells which are discharged (under nervous
control?) sometimes exposing barbs and frequently contain a toxin that can
enter the body of the prey. Some are extremely potent (sea wasps
) and have killed humans...respiratory paralysis. Sea slugs are known to
pirate Nematocysts (stinging cells) and use them for their own protection.
Cnidaria
http://www.gotosnapshot.com/Ovate/ovate_catalog.html
Ctenophores
Comb
Jellies Phylum: Ctenophora
About
90 species ...worldwide and marine distribution.
4cm
to 1m in size.
.radial
symmetry with eight rows of plates..fused
cilia (comb) for locomotion.
Ctenophores
Fewer than
100 species have been described. They are classified on the basis of their
tentacles
Body form
oral
lobes,
gastrovascular
divisions
body
compressions.
Ctenophores
1. These are a group of bi-radial
jellyfish called comb jellies because of the presence of ciliated comb plates
used in locomotion. Their
continuous
beating refract light creating a prism-like multicolor effect. Each row is a
series of small paddles and each paddle is
Ctenophores
composed
of thousands of tiny cilia. Collectively, the cilia produce a color spectrum in
much the same way as a diffraction grating or the surface of a compact disk.
Entirely marine and mostly pelagic or planktonic...some
can creep.
2. Only body
cavity is the gastrovascular cavity in the form of
canals.
Ctenophores
3. The body
wall is composed of an epidermis, layer of collenchyme,
and a gastrodermis. Collenchyme
contains amoebocytes, connective tissue and true muscle
cells, so its more advanced than the mesoglea in
cnidarians.
4. Most
ctenophores possess on their tentacles adhesive cells called colloblasts. The tentacles are used for catching prey and
Ctenophores
balancing
organs (nematocysts in cnidarians and only one ctenophore).
5. Skeletal
structures and excretory and respiratory organs are lacking.
6. Varied
shapes
7. Well
developed statocyst at pole and a nerve net system in
epidermis
Ctenophores
Comb jellies
are virtually all true plankton (drifters)-dwellers whose almost invisible
transparent bodies drift in the oceans trailing tentacles like fishing lines.
These are armed
with lasso cells that explode and ensnare their microscopic prey.
Ctenophores
Phylum Ctenophora
Class Tentaculata with tentacles
Order Cydippida Pleurobrachia
Order Lobata Mnemiopsis
Order Cestida Velamen
Order Platyctenea Ctenoplana
Class Nuda without tentacles
Order Beroida Beroe
Worms
LOPHOPHORATES
Three phyla of marine animals, Ectoprocta,
formally Bryozoa, Brachiopdoa
and Phoronida, are characterized by a lophophore, a circular or U-shaped ridge around the mouth bearing
either one or two rows of ciliated, hollow tentacles.
Worms
Because of this unusual feature, they are thought to be
related to one another.
The coelomic cavity of them lie
within the lophophore and its tentacles and the anus
is always elsewhere.
The lophophore functions in these
animals as a food collection organ and as a surface for gas exchange.
Worms
They are attached to the substratum or move slowly, using the
cilia of the lophophore to capture the plankton on
which they feed.
Worms
Phylum Phoronida resemble common
tube worms seen on dock pilings.
Look like polychaete worms.
They secrete a chitinous tube within
which it lives out its life and they also extend tentacles to feed and quickly
withdraw them when disturbed but that's where the resemblance to the tube worm
ends.
Worms
The Phoronida is one of the smallest and least familiar phyla;
there are about twelve or so living species in two genera, Phoronis
and Phoronopsis. However, phoronids
-- or "horseshoe worms," as they are sometimes called -- may be
abundant in shallow marine sediments at certain localities.
Worms
Phoronids
are elongated and worm- shaped, but the gut loops and ends close to the mouth,
instead of passing straight through the body as in annelids and many other wormlike
organisms
Worms
There is no straight tube within a tube but a U-shaped gut
within a sac.
Only 12 species are known ranging in length from a few mm to
30 cm.
Some lie buried in sand and others attach to rocks signally or
in groups.
Worms
Phylum Ectoprocta (Bryozoa) look like tiny short versions of the phoronoids
..small .5mm and colonial and called moss animals.
The new name, ectoprocta refers to
the location of the anus (proct) which is external to
the lophophore.
Worms
4000 species include marine and freshwater forms..only non-marine lophophores.
Most live in shallow water but some live at 18,000 feet.
Worms
Individuals secrete a tiny chitinous
or limestone chamber, ZOECIUM, attached to other members of the colony and to
rocks.
Individuals communicate chemically through pores between
chambers.
Worms
Their taxonomy depends on the sizes shape, and organization of
the colonies.
The arrangement of the zooids on the colonies is also highly variable.
Some are important as pests as they can foul up piers, pilings, buoys and ship
hulls.
Worms
PHYLUM BRACHIOPODA or lampshells
Bottom dwelling clamlike
organism that are permanently attached to the substrate and possess a complex lophophore, which consists of two spiral ciliated tentacles
resembling arms.
Classification
key http://paleo.cortland.edu/tutorial/Brachiopods/brachclass.htm
Worms
The LOPHOPHORE is a circular or U-shaped ridge around the
mouth bearing either one or two rows of ciliated, hollow tentacles
Worms
The lamp shells resemble clams because they have two shells
but these shells are hinged so that one shell covers the top and the other its
bottom side (dorsal and ventral whereas the clam its
the left and right side.
Worms
Many species attach to rocks or sand by stalks that protrude
from within the shell, a contractile muscle called the PEDUNCLE, while others
become cemented by shell secretions to the substratum.
Worms
These shells feed on particles suspended in the water, the
cilia creating water currents sweeping food particles onto the lophophore which lies within the shell (as opposed to
others that are outside).
Worms
There are only 300 species of brachiopods existing today but
more than 30,000 species are known as fossils with the genus Lingula having fossil records back to 500 million years.
Worms
Worms... Nematode sea worms are the most numerous of all sea
or land animals with an estimated population of 40 septillion.
The convoluta worm feeds only once
in its life feeding off a special algae and is
sustained by starches made through photosynthesis by the algae it swallowed.
Most
modern reports say that Convoluta roscoffensis needs the algal cells (Platymonas
convoluta) to survive. The algae cells inside the
worm are rounded and hardly look like an algal cell. However
when they are released into the sea water the quickly change shape and swim to
nearby flatworm eggs where they burrow inside the eggs and grow and multiply
inside the developing flatworm embryo. Another species, Convoluta paradoxa
is thought to have photosynthetic diatoms in its tissues.
Biology of the acoel flatworm Convoluta roscoffensis
Sheltered
sandy beaches of the bretonic coast (near Roscoff, Carantec, Carnac, La Trinite sur mer) are well-known
habitats of the acoel flatworm Convoluta
roscoffensis (order: Acoela,
phylum: Platyhelminthes) which can be
found there in summer time on a massive scale.
© All
photos and information kindly provided by:Arthur
Hauck
, Germany
Protozoan sponge review answers
Lecture Marine
Protozoans ANS
1. They are
multicellular
2. are important contributors of calcareous material in coral
reefs and sandy beaches
3. are planktonic marine protozoanssecrete shells of silica (SiO2)are microscopic,
but may form giant colonies
4.foraminiferans, or foramsradiolariansciliates
5. Which of the following are Protists?foraminiferans, or foramsradiolariansciliates dinoflagellates
6. collar cells - calcareous structures of the sponge's
skeleton
7. radiolarian.
8 filter feeders
9 a digestive tract symmetrical body plan nerve cells
10 absorbing food distributed by amoeboid like cells
11 skeleton
12 collar cells pores water flow
13A cellular level of organization. Incipient tissues with a low level of integration.A unique water current system powered by choanocytes.A body with incurrent openings (called ostia) for water intake.
14 Fibrillar collagen (a
protein)Calcareous spiculesSiliceous
spiculesModified collagen called spongin
15
AsconoidSyconoidLeuconoid
16 Choanocytes
17 Archaeocytes
18 True
tissues and organs
19 Radial canalsIncurrent canalsProsopylesApopyles
29 Regeneration
21 Glass sponges
22 Leuconoid
23 . a shell
24 Because of
their diversity, is it difficult to define what a typical protist
is.
VCC Invert 2 questions
c 1. proboscis
2
Cnidarians
3. one swims and the other is sessile
4. stinging cells
5. up and down
)6 Hydrozoa
7/9Anthozoa 8Scyphozoa
10. sensitive to
gravity/equilibrium