I.I. CnidariaCnidaria

D.D. AnthozoaAnthozoa• More species than Hydrozoa or ScyphozoaMore species than Hydrozoa or Scyphozoa• No medusa stageNo medusa stage• Polyps more complex than in other classesPolyps more complex than in other classes

• Gut contains Gut contains septasepta to add surface area for digestion of prey to add surface area for digestion of prey• Passive suspension feeders and predatorsPassive suspension feeders and predators1.1. SolitarySolitary forms forms

• Sea anemones – polyps may be very largeSea anemones – polyps may be very large

2.2. ColonialColonial forms formsa.a. CoralsCorals

• Stony corals – branching and doming (massive)Stony corals – branching and doming (massive) - Some build reefs in tropics- Some build reefs in tropics• Soft coralsSoft corals

b.b. Precious corals – Protein skeleton + spiculesPrecious corals – Protein skeleton + spiculesc.c. Gorgonians (sea whips, sea fans) – Tough protein skeletonGorgonians (sea whips, sea fans) – Tough protein skeletond.d. Sea pens – No skeletonSea pens – No skeletone.e. Sea pansies – No skeleton; some bioluminescentSea pansies – No skeleton; some bioluminescent

Anthopleura xanthogrammica

Branching Corals Doming Corals

Soft Corals Precious Corals

I.I. CnidariaCnidaria

D.D. AnthozoaAnthozoa• More species than Hydrozoa or ScyphozoaMore species than Hydrozoa or Scyphozoa• No medusa stageNo medusa stage• Polyps more complex than in other classesPolyps more complex than in other classes

• Gut contains Gut contains septasepta to add surface area for digestion of to add surface area for digestion of preyprey

• Passive suspension feeders and predatorsolitary Passive suspension feeders and predatorsolitary formsforms

• Sea anemones – polyps may be very largeSea anemones – polyps may be very large2.2. Colonial formsColonial forms

a.a. CoralsCorals• Stony corals – branching and doming (massive)Stony corals – branching and doming (massive) - Some build reefs in tropics- Some build reefs in tropics• Soft coralsSoft corals

b.b. Precious corals – Protein skeleton + spiculesPrecious corals – Protein skeleton + spiculesc.c. Gorgonians (sea whips, sea fans) – Tough protein Gorgonians (sea whips, sea fans) – Tough protein

skeletonskeletond.d. Sea pens – No skeletonSea pens – No skeletone.e. Sea pansies – No skeleton; some bioluminescentSea pansies – No skeleton; some bioluminescent

Anthopleura xanthogrammica

Gorgonians (Sea Whips)

Gorgonians (Sea Fans)

I.I. CnidariaCnidaria

D.D. AnthozoaAnthozoa• More species than Hydrozoa or ScyphozoaMore species than Hydrozoa or Scyphozoa• No medusa stageNo medusa stage• Polyps more complex than in other classesPolyps more complex than in other classes

• Gut contains Gut contains septasepta to add surface area for digestion of prey to add surface area for digestion of prey• Passive suspension feeders and predatorsPassive suspension feeders and predators1.1. Solitary formsSolitary forms

• Sea anemones – polyps may be very largeSea anemones – polyps may be very large

2.2. Colonial formsColonial formsa.a. CoralsCorals

• Stony corals – branching and doming (massive)Stony corals – branching and doming (massive) - Some build reefs in tropics- Some build reefs in tropics• Soft coralsSoft corals

b.b. Precious corals – Protein skeleton + spiculesPrecious corals – Protein skeleton + spiculesc.c. Gorgonians (sea whips, sea fans) – Tough protein skeletonGorgonians (sea whips, sea fans) – Tough protein skeletond.d. Sea pens – No skeletonSea pens – No skeletone.e. Sea pansies – No skeleton; some bioluminescentSea pansies – No skeleton; some bioluminescent

Anthopleura xanthogrammica

Sea Pens

I.I. CnidariaCnidaria

D.D. AnthozoaAnthozoa• More species than Hydrozoa or ScyphozoaMore species than Hydrozoa or Scyphozoa• No medusa stageNo medusa stage• Polyps more complex than in other classesPolyps more complex than in other classes

• Gut contains Gut contains septasepta to add surface area for digestion of prey to add surface area for digestion of prey• Passive suspension feeders and predatorsPassive suspension feeders and predators1.1. Solitary formsSolitary forms

• Sea anemones – polyps may be very largeSea anemones – polyps may be very large

2.2. Colonial formsColonial formsa.a. CoralsCorals

• Stony corals – branching and doming (massive)Stony corals – branching and doming (massive) - Some build reefs in tropics- Some build reefs in tropics• Soft coralsSoft corals

b.b. Precious corals – Protein skeleton + spiculesPrecious corals – Protein skeleton + spiculesc.c. Gorgonians (sea whips, sea fans) – Tough protein skeletonGorgonians (sea whips, sea fans) – Tough protein skeletond.d. Sea pens – No skeletonSea pens – No skeletone.e. Sea pansies – No skeleton; some bioluminescentSea pansies – No skeleton; some bioluminescent

Anthopleura xanthogrammica

Sea Pansies

I.I. CnidariaCnidaria

E.E. CubozoaCubozoa• Sea wasps, Box jellyfishSea wasps, Box jellyfish• Small medusaeSmall medusae• Life cycles poorly known; include polyp Life cycles poorly known; include polyp

stagestage• Highly toxicHighly toxic• Eat fishes, worms, arthropodsEat fishes, worms, arthropods

II.II. CtenophoraCtenophora

• Comb jelliesComb jellies• Exclusively marine (100 species)Exclusively marine (100 species)• Radial symmetryRadial symmetry• Eight rows of Eight rows of ciliary combsciliary combs

• Used for swimming Used for swimming videovideo

• CarnivorousCarnivorous• Lack nematocystsLack nematocysts• Capture prey with sticky Capture prey with sticky colloblastscolloblasts

• May occur in swarmsMay occur in swarms• Heavy predators on plankton, including fish larvaeHeavy predators on plankton, including fish larvae

• Body formsBody forms• TentaculateTentaculate – Planktivores – Planktivores• LobateLobate - Ctenophorivores - Ctenophorivores

II.II. CtenophoraCtenophora

• Comb jelliesComb jellies• Exclusively marine (100 species)Exclusively marine (100 species)• Radial symmetryRadial symmetry• Eight rows of Eight rows of ciliary combsciliary combs

• Used for swimmingUsed for swimming

• CarnivorousCarnivorous• Lack nematocystsLack nematocysts• Capture prey with sticky Capture prey with sticky colloblastscolloblasts

• May occur in swarmsMay occur in swarms• Heavy predators on plankton, including fish larvaeHeavy predators on plankton, including fish larvae

• Body formsBody forms• TentaculateTentaculate – Planktivores – Planktivores• LobateLobate - Ctenophorivores - Ctenophorivores

Beroe

Pleurobrachia

Lobate

Tentaculate

III.III. WormsWorms

• Body shape very common in Body shape very common in invertebratesinvertebrates

• Especially in mobile invertebratesEspecially in mobile invertebrates• FlexibilityFlexibility• ManeuverabilityManeuverability

• Bilateral Symmetry**Bilateral Symmetry**• CephalizationCephalization

• ““Head” end with Head” end with • Accumulation of nerve tissue (“brain”)Accumulation of nerve tissue (“brain”)• Sensory structuresSensory structures

• Anterior – PosteriorAnterior – Posterior• Dorsal - VentralDorsal - Ventral• Left - RightLeft - Right

Fig. 7.12

IV.IV. PlatyhelminthesPlatyhelminthes

• Flatworms - Dorsoventrally flattenedFlatworms - Dorsoventrally flattened• Simplest bilaterally symmetrical Simplest bilaterally symmetrical

organismsorganisms• First organs and organ systems**First organs and organ systems**

• Central nervous systemCentral nervous system• Simple “brain” coordinates muscle Simple “brain” coordinates muscle

movementsmovements

• Incomplete digestive systemIncomplete digestive system• Mouth but no anusMouth but no anus• Similar to Cnidaria and CtenophoraSimilar to Cnidaria and Ctenophora

• Mesoderm**Mesoderm**• Cell layer between endoderm and ectodermCell layer between endoderm and ectoderm• Gives rise to muscles, reproductive systemGives rise to muscles, reproductive system

IV.IV. PlatyhelminthesPlatyhelminthes

A.A. TurbellariaTurbellaria• Mostly free-living carnivorous speciesMostly free-living carnivorous species• Most commonly seen (Most commonly seen (Why?Why?))• Some live as Some live as commensalcommensal animals inside animals inside

other invertebrates (oysters, crabs, etc.)other invertebrates (oysters, crabs, etc.)

IV.IV. PlatyhelminthesPlatyhelminthes

B.B. Trematoda (Flukes)Trematoda (Flukes)• Most species (6000)Most species (6000)

• Parasitic – Feed on tissues, blood, gut contentsParasitic – Feed on tissues, blood, gut contents• Complex life cyclesComplex life cycles

• Adults live in vertebrate host (fish, whale, bird)Adults live in vertebrate host (fish, whale, bird)• Larvae may inhabit invertebrates (intermediate Larvae may inhabit invertebrates (intermediate

hosts)hosts)• Vertebrate eats intermediate host (clam, snail, etc.)Vertebrate eats intermediate host (clam, snail, etc.)

C.C. Cestoda (Tapeworms)Cestoda (Tapeworms)• ParasiticParasitic• Live in vertebrate intestinesLive in vertebrate intestines

• Head attaches to intestine wall with suckers or hooksHead attaches to intestine wall with suckers or hooks• Gutless – absorb nutrients through body wallGutless – absorb nutrients through body wall• May reach 50 feet!! (sperm whales)May reach 50 feet!! (sperm whales)

V.V. NemerteaNemertea

• Ribbon wormsRibbon worms• CosmopolitanCosmopolitan

• Most common in shallow, temperate Most common in shallow, temperate regionsregions

• Complete digestive tract**Complete digestive tract**• Mouth and anusMouth and anus

• Circulatory system**Circulatory system**• Use long, fleshy Use long, fleshy proboscisproboscis to capture to capture

preyprey• Feed on crustaceans and wormsFeed on crustaceans and worms

• May be cryptic or conspicuousMay be cryptic or conspicuous• Can reach 30 m in length!!Can reach 30 m in length!!