Transcript Sponges and Cnidarians

Origin

Evolution: believed to
have evolved from
protists
 Collar cells: are almost
identical to many
flagellated protist cells
 Uses of collar cells:
▪ Move water, ingest food
and excrete waste
Diversity
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Species #: 8300
Variety:
 3% live in
freshwater
 Variety of shapes,
sizes and colors
 Live at a variety of
sea depths
 Kingdom Animalia
 Phylum Porifera
 They are mostly marine (live in salt
water)
 # of cells: multicellular (eukaryotic)
 Body contains pores, canals and
chambers that allow for water flow
 Symmetry: radial
 No definite head region
 Interior surface: lined with collar
cells (choanocyte)
 Choanocyte:
▪ a flagellated collar
cell that lines the
inner surface (mesophyll) of
sponges
 Beating flagella
 Create water
current
 Capture food
and water
particles
 Carries away
waste
 Collar is made
of microvilli
 Why? To
create a
filtering
device to
collect food
 The food
particles then
become trapped
 How? Taken in
by the food
vacuoles (where
they are stored
and digested)
Actual Choanocyte at work
 Efficient? Non-efficient?
 Why?
▪ Lots of collar cells working together
 Made of ?
 Spicules – calcareous or siliceous,
support structures
 Spongin – fibrous
proteins, made of
collagen
Fun fact:
When you wash
with natural
sponges, this is
the portion you
wash/exfoliate
with!

Reproduce asexually or sexually
 By? Budding or gemmules (asexual), sperm and
egg (sexual)

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Larva: motile, move
Adults: sessile, don’t move
Sponge Love
Scene #1
Sexual
Sponge Love
Scene #2
Budding
1. Asconoid

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Def: one large
body cavity
Characteristics:
▪ Collar cells line the
main body cavity
▪ Contain many pores
2. Syconoid


Def: many
canals, water
flows through
each canal
Characteristics:
▪ Collar cells line
canals
▪ Can filter more
water
3. Leuconoid
Def: contains
chambers
 Characteristics:
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
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collar cells line
chambers
Often used for
shower sponges
 Kingdom: Animalia
 Phylum: Porifera
 Class Calcarea
 Class Hexactinellida
 Class Demospongiae
 Spicules
 Made of calcium carbonate (like
baking soda)
 Shape: needle shaped,
3-4 sections/rays
 Body types?
 All three types represented
 Spicules
 Made of? Silica (glass-like)
 Description: Six sections/rays
 Body types? Asconoid or leuconoid
 Often called?
 Glass sponges
 Spicules
 Made of: silica
 Description: don’t have 6 rays
 Body types? Leuconoid only
 Other characteristics:
 Make up 95% of all sponges
 Use this type in bath/shower

Kingdom Animalia
 Phylum Cnidaria

Examples:
 Hydra, sea anemone, jellyfish, Portuguese-man-o-
war, moon jelly, sea pen, coral

Where do they live???
 Aquatic (mostly marine/salt-water)
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Symmetry: Radial or biradial
Head region? No definite head region
Two basic types:
1.
2.
Polyp: tentacles facing upwards
Ex: sea anemone, coral
Medusa: tentacles facing downwards
Ex: jellyfish, man-o-war
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Polyp –
 Lifestyle of polyps? Sessile (do not move)
 Body shape? Tubular (tube-like)
 Mouth: Surrounded by tentacles (facing up)
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Medusa –
 Lifestyle? Mobile/motile (move)
 Body shape? Umbrella shaped
 Mouth : surrounded by tentacles that face
downwards
Body forms? Most cnidarians exist as
BOTH body forms at some point during
their life cycle
POLYMORPHIC
 Reproduction

 Polyp: reproduce asexually using budding
 Medusa: reproduce sexually using
sperm/egg
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Two layered body
 Epidermis –
▪ Def: outer part of the body
▪ Derived from? Ectoderm
 Gastrodermis –
▪ Def: inner part of the body
▪ Derived from? Endoderm
▪ Lines the gut cavity
▪ Main function: digestion

Tentacles contain cnidocytes
 Function: aid in capture of prey/food
 Characteristics: armed with nematocysts
 Nematocyst: stinging cell (contains
hook/barb used to catch)
 Stinging cells
 Contain filament
 When do they uncoil? When they
are touched by animals (in the
environment)
 Contain barb or spine
 Poisons can be injected
Nematocyst Firing
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Class Hydrozoa

Class Scyphozoa

Class Cubozoa

Class Anthozoa
Solitary (live as an individual)
Colonial (live in groups)
Reproduce? Asexually (Polyp form) OR
sexually (medusa form)
 Where do they live? Freshwater OR
marine/salt-water
 Examples: Hydra, Tubularia
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Polyp
Medusa
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Movement: Solitary (live by themselves, but
MOVE quiet a bit)
Body form: Medusa form (most)
Where do they live? All marine/salt-water
Organs? Sensory organs found on the ridge
of the umbrella
Examples: Cassiopeia, Aurelia
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Movement: Solitary (live by themselves but
MOVE quite a bit)
Body form: Medusa form (most)
Where do they live? All marine/salt-water
Characteristics? Umbrella is more square in
shape
Examples: Tripedalia, Carybdea
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Movement: Solitary (individual)or colonial
(group); tentacles move some (but animals
are fixed to a spot, usually)
Body form: all polyps (no medusas!)
Where do they live? All marine/salt-water
Examples:
 Exist in three subclasses
▪ Subclass Hexacorallia
▪ Subclass Ceriantipatharia
▪ Subclass Octocoral

Human Uses
 Bioindicators: provide info about the
environment/oceans/water bodies
▪ Sponges
▪ Filter water
▪ Pollutants are concentrated in collar cells
▪ Corals:
▪ sensitive to water pollution (loose coloration)
 Help protect shore line from erosion
(decrease force of waves)
 Biomedical/Pharmaceutical industry
1. New antibiotics
2. Anticancer compound found
in small % of sponges
 Consumer products
1. Natural sponges (bathing)
2. Spicules used in clay to
strengthen ceramic pots, etc

In the Environment
 Form of food, camouflage and protection
for other animals
 Many symbiotic relationships
 Corals and Sponges
▪ The most abundant animal in most reefs
▪ Base of most aquatic food chains
▪ May be used as camouflage
▪ Ex: Crab species place sponges on their backs for protection
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Other relationships
 Cnidarians with dinoflagellates(protists)—
▪ Form reefs when this relationship occurs
 Homes for other organisms
▪ Shrimp, clown fish and eels use sponges as homes
▪ Coral reefs provide protection