Phylum Porifera & CnidariaPhylum Porifera & Cnidaria

SpongesSponges

• Belong to phylum Porifera• Sessile• Around 10,000 species• Less specialized than other animals• No true tissues or organs• Grow in many shapes, sizes, & colors• Can be as small as 1 cm or as large as 2 m

• Belong to phylum Porifera• Sessile• Around 10,000 species• Less specialized than other animals• No true tissues or organs• Grow in many shapes, sizes, & colors• Can be as small as 1 cm or as large as 2 m

Body PlanBody Plan

• Tube-like & asymmetrical• Osculum: • Opening at top of sponge. Water leaves through it• Collar cells:• Also called “choanocytes”• Innermost lining of sponge• Lined with flagella, draws water in and circulates it• Spongin & spicules:• Make up skeletons of sponges• Helps to support body of sponge under water pressure

• Tube-like & asymmetrical• Osculum: • Opening at top of sponge. Water leaves through it• Collar cells:• Also called “choanocytes”• Innermost lining of sponge• Lined with flagella, draws water in and circulates it• Spongin & spicules:• Make up skeletons of sponges• Helps to support body of sponge under water pressure

QuickTime™ and a decompressor

are needed to see this picture.

Feeding & DigestionFeeding & Digestion

• Filter feeders

• Food includes: bacteria, protozoans, algae, etc

• Food is digested by collar cells

• Nutrients pass to amoebocytes….

• Amoebocytes:

• Cells that crawl/migrate to different parts of the sponge and deliver food

• Filter feeders

• Food includes: bacteria, protozoans, algae, etc

• Food is digested by collar cells

• Nutrients pass to amoebocytes….

• Amoebocytes:

• Cells that crawl/migrate to different parts of the sponge and deliver food

ReproductionReproduction

• Reproduce asexually by budding

• Can regenerate broken body parts

• Reproduce sexually also

• Sperm released from one sponge enter pores of another

• Collar cells….amoebocytes…..eggs….fertilization

• Forms a larva

• Some sponges are separate sexes

• Most hermaphroditic

• Reproductive success!! Why??

• Reproduce asexually by budding

• Can regenerate broken body parts

• Reproduce sexually also

• Sperm released from one sponge enter pores of another

• Collar cells….amoebocytes…..eggs….fertilization

• Forms a larva

• Some sponges are separate sexes

• Most hermaphroditic

• Reproductive success!! Why??

Phylum CnidariaPhylum Cnidaria

• Bodies constructed of two cell layers:

• Epidermis, gastrodermis

• Gut = “gastrovascular cavity”

• Two body types:

• Polyp (sessile)

• Medusa (motile)

• Bodies constructed of two cell layers:

• Epidermis, gastrodermis

• Gut = “gastrovascular cavity”

• Two body types:

• Polyp (sessile)

• Medusa (motile)

QuickTime™ and a decompressor

are needed to see this picture.

QuickTime™ and a decompressor

are needed to see this picture.

QuickTime™ and a decompressor

are needed to see this picture.

Feeding & DefenseFeeding & Defense

• Cnidocytes = stinging cells

• Nematocyst = stinging structure

• Uses a trigger mechanism

• Poison from stingers paralyzes prey

• Cnidocytes = stinging cells

• Nematocyst = stinging structure

• Uses a trigger mechanism

• Poison from stingers paralyzes prey

QuickTime™ and a decompressor

are needed to see this picture.

ClassesClasses

• Class Hydrozoa:

• Portugese Man o’ War

• Hydras (exist only as polyps). Fresh, salt water

• Class Scyphozoa:

• Jellyfish

• Class Anthozoa: (flower-like)

• Coral reefs

• Class Hydrozoa:

• Portugese Man o’ War

• Hydras (exist only as polyps). Fresh, salt water

• Class Scyphozoa:

• Jellyfish

• Class Anthozoa: (flower-like)

• Coral reefs

QuickTime™ and a decompressor

are needed to see this picture.

QuickTime™ and a decompressor

are needed to see this picture.

Jellyfish LifecycleJellyfish Lifecycle

• Medusas release gametes

• Gametes form zygote

• Zygote morphs into a planula larva

• Planula attaches to ocean floor

• Matures into a polyp

• Polyp buds out, making young medusas

• Young medusas mature, and cycle starts again

• Medusas release gametes

• Gametes form zygote

• Zygote morphs into a planula larva

• Planula attaches to ocean floor

• Matures into a polyp

• Polyp buds out, making young medusas

• Young medusas mature, and cycle starts again