Porifera

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Porifera Cnidaria

• Read 500-518
• HW 503 1,3
• 511 1-3
• 518 2-3
• NR 4 due next class

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Kingdom Anamalia

• Eukaryotic
• Heterotrophs
• Multicellular
• Lack cell walls
• Embryonic formation of gastula

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Animal Development

• Blastula- a stage during which a zygote forms a
  hollow ball of cells
• Gastula- A stage when the hollow ball folds in on
  itself forming a cuplike shape.

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Early similarities

• Similarities in animals can also be seen during
  the embryonic stages.

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Directions

• Anterior
• Posterior
• Dorsal
• Rostral
• Ventral
• Caudal
• Distil
• Medial

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Porifera

• Also known as sponges.
• Named due to their porous structure.
• Sponges are sessile (non-mobile) and require a
  watery environment for survival.
• Sponges are asymmetric (there is no distinct
  shape or body pattern).
• No nervous system

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Sponge Anatomy

• Osculum- The opening at the top of the sponge.
• Amebocytes- cells that move throughout a sponges
  body supplying nutrients and removing wastes.
• Spongin- A network of protein fibers for
  structure
• Spicules- Needle-like structures made of glass or
  calcium carbonate also for structure

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Reproduction

• Sponges are able to reproduce either sexually or
  asexually. Watch
• Asexual reproduction is typically through budding
  or regeneration.
• Can also form new structures called gemmules.
• A dormant mass of amebocytes surrounded by
  spicules that emerge when favorable conditions
  return.
• Sexual reproduction is mostly hermaphroditic.
• Most species of sponge can produce both male and
  female gametes.
• Uses water currents to exchange gametes with
  other sponges.

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Unique

• Sponges are unlike most other animals and are
  considered closely evolved from colonies of
  protists.
• Sponges lack specialized tissues and organ
  systems.
• Sponges lack body symmetry.
• Sponges can rearrange internal and external cells
  freely.

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Major Classes

• Calcarea- table 1
• Hyalospongiae- table 2
• Demospongiae- table 3
• Sclerospongiae- table 4

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Cnidaria

• Cnidarians have radial symmetry.
• Contain a single opening surrounded by tentacles.
• Named due to their unique cells called cnidocytes
  which are used for stinging.
• Contain a simple nerve net and simple sensory
  organs.
• Watch

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Anatomy

• Polyp- a cylindrical or vase-shaped opening on
  the dorsal surface with upward facing tentacles.
• Medusa- An umbrella or bell-shaped opening on the
  ventral surface with downward facing tentacles.

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Cnidocytes

• The specialized cells use nematocysts to capture
  prey.
• Each nematocyst is a coiled filament with a
  poison tipped-harpoon at the end.

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Reproduction

• Like Porifera, Cnidaria can reproduce both
  asexually and sexually.
• Sexual reproduction may require cycles involving
  both polyp and medusa forms.
• Planula- a larval stage zygote after sperm and
  eggs fertilize in open water.

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Major Classes

• Milestone(s) Radial symmetry, specialized
  tissues
• Hydrozoa- table 5
• Scyphozoa- table 6
• Anthozoa- table 7

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Phylum Class Exploration

• Each table has been assigned a class from either
  porifera or cnidaria.
• In the next 20 minutes collect the following
• 1 sample species, both common name and binomial
  nomenclature
• 5 pictures of organisms in that class
• What makes that class different from other
  classes in the same phylum.