Phylum:
Porifera
Porifera
Origin of the word porifera: Latin for pore bearer
Animals in this phylum include: Sponges
Level of organization: Cellular level, multicellular
(no tissues or organs)
Types of cells found in a sponge
Epidermal Cell: Makes up the “skin” of
the sponge
Amoebocyte: Transports nutrients to all
the cells and produce sperm and egg.
Porocyte: Allows water containing
nutrients to flow into the sponge
Collar Cell (Choanocyte):
1) Contain a flagella that beat creating a
current that moves water through
the sponge
2) Collar traps food particles. These
particles are then moved into
vacouoles where they are picked up
by amoebocytes
Spicules
Non Cellular structure
Spicules: sharp rigid structures
responsible for structural
support (Similar to the
human skeleton). Usually
made from :
1) silicon,
2) calcium
3) spongin (type of protein)
=Sponges are classified in
these three groups
Feeding type
Feeding type: Sessile Filter feeder
Sessile: Does not move
Filter Feeder: Functions like a strainer. Picks out
small food particles from the water.
Reproduction
Capable of two modes
of reproduction:
Asexual: Fragmentation, Budding, Gemmule
production (gemmule = spore)
Reproduction
Capable of two modes
of reproduction:
Sexual:
1)Sperm released by the sponge through
chimney (Osculum).
2) The sperm is taken in through pores of
other sponges
3) Sperm fertilizes the eggs in the body
of the sponge
4) fertilized egg develops into a
flagellated offspring that will swim out
to find a new habitat
Note: most sponges are hermaphroditic
Phylum:
Cnidaria
Cnidaria
Origin of the word Cnidaria: Latin for sea nettle
Animals in this phylum include: Anemones, corals,
jellyfish, and hydra (the only fresh water species)
Level of o
Cnidaria
Origin of the word Cnidaria: Latin for sea nettle
Animals in this phylum include: Anenomes,
corals, jellyfish, and hydra (the only fresh
water species)
Level of organization: Tissue level, (no organs)
Symmetry: radial
Cnidarian sting
Cnidocyte: Specialized stinging cell
Nematocyst: Long thread like tube containing
spines and barbs
tent
Cnidarian sting
Cnidocyte: Specialized stinging cell
Nematocyst: Long thread like tube containing
spines and barbs
HOW DOES IT WORK?
1) Trigger on the cnidocyte is activated via touch
2) Cnidocyte then releases the nematocyst
3) Thread (filament) enters prey
4)Nematocyst spines penetrates skin releasing
paralyzing toxins
5) Prey is brought up to gastrointestinal cavity
Feeding
Gastrovascular Cavity: A bag-like cavity with one
opening. Lined with gastrodermis (made from
endoderm).
Gastrodermis contains gland cells that release
digestive enzymes.
Body Forms
Two Body Types:
Polyp: Mouth at apex. Sessile
predator.
eg. Anemone
Medusa: Mouth at base. Mobile
predator.
= Can take advantage of new
richer, feeding grounds and
congregate in large numbers
to breed
eg. Adult jellyfish
Cnidarian Life Cycle
Notes on reproduction
For most jellyfish with a polyp and a medusa
form in their life cycle
- Polyp is only capable of asexual reproduction
- Medusa is the sexually reproductive stage
Asexual Reproduction
-|Fragmentation and budding
Assignment
Questions 1-10