Intro to Invertebrates

Classification OverviewCommon Invertebrates

KingdomAnimalia

PhlyumPorifera

Cnidaria

Mollusca

Arthropoda

Echinodermata

Spineless creatures

● Invertebrates are animals that lack a backbone

● You may know many examples of these creatures that live in the ocean: jellyfish, sponges, corals, crabs

● Can you think of others?

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● Phylum: Porifera● Simple heterotrophs with two cell types:

– Collar cells have flagella and draw water into the sponge’s central cavity (diagram right)

– Epithelial cells line the sponge’s outer surface

● Reproduce asexually by budding or sexually by release of sex cells (gametes) into the water

● Filter feeders: feed by filtering suspended materials out of water

Phylum Porifera: Sponges

Flagellum

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Collarcell

Video

Video

● Phylum: Porifera● Simple heterotrophs with two cell types:

– Collar cells have flagella and draw water into the sponge’s central cavity (diagram right)

– Epithelial cells line the sponge’s outer surface

● Reproduce asexually by budding or sexually by release of sex cells (gametes) into the water

● Filter feeders: feed by filtering suspended materials out of water

Phylum Porifera: Sponges

Flagellum

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Collarcell

The yellow tube sponge, purple vase sponge, red encrusting sponge and gray rope sponge

Photo: NOAA

● Cnidarians include corals, anemones, sea fans, and jellyfish

● Cnidarian characteristics:– Radial symmetry – they are

symmetrical around a single point, like a clock

– Two tissue layers separated by a jelly layer (mesoglea)

– Nematocysts – structures on their tentacles that have stinging toxins

Phylum Cnidaria: The stinging nettles

Cnidarian TaxonomySome Common Classes

KingdomAnimalia

PhylumCnidaria

ClassesAnthozoa – anemones,CoralsScyphozoa – jellyfishHydrozoa – fire corals,Portuguese Man-of-War

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Video

● Cnidarians include corals, anemones, sea fans, and jellyfish

● Cnidarian characteristics:– Radial symmetry – they are

symmetrical around a single point, like a clock

– Two tissue layers separated by a jelly layer (mesoglea)

– Nematocysts – structures on their tentacles that have stinging toxins

Phylum Cnidaria: The stinging nettles

Cnidarian TaxonomySome Common Classes

KingdomAnimalia

PhylumCnidaria

ClassesAnthozoa – anemones,CoralsScyphozoa – jellyfishHydrozoa – fire corals,Portuguese Man-of-War

This purple striped jellyfish (Pelagia panopyra) has a potent sting

Photo:NOAA

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Some special Cnidarian species profiles

Portuguese Man-of-WarClass: HydrozoaOrder: Siphonophora

These are in a different class than jellyfish, they are colonies – specialized polypsPhoto: NOAA

Photo:

NO

AA

Fire coralClass: HydrozoaOrder: Capitata

These are in a different class than typical hard corals - you will get a mild burn if you touch them!

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Phylum Mollusca: Three defining traits ● Mollusks include oysters,

clams, mussels, conchs, snails, sea slugs, squid and octopuses

● Most mollusks have three traits– Mantle: a muscular bag

surrounding the gills and other organs for circulation

– A muscular foot for movement– A radula: a rough scraping

appendage for feeding or protection

Mollusca TaxonomySome Common Classes

KingdomAnimalia

PhylumMollusca

ClassesGastropoda – snails, sea slugsBivalvia – clams, oysters, scallops, musselsCephalopoda – squid, octopus

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Video

Some mollusks

OctopusClass: Cephalopoda

The foot of the octopus is divided intoeight arms.

Spiny oysterClass: Bivalvia

Bivalves have two shells and no typical“head” like other mollusks

Photos:

NO

AA

Foot

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Phylum ArthropodaSuperclass/Subphylum Crustacea

● Arthropods are land and sea “bugs”

● Crustaceans include shrimps, crabs, lobsters, copepods and barnacles

● About 1 million species exist● Crustacean characteristics:

– Two pairs of antennae– Mandibles for chewing– Hard exoskeleton– Jointed legs

Crustacean TaxonomySome Common ClassesKingdomAnimalia

PhylumArthropodaSubphylumCrustacea

ClassesCirripedia – barnaclesCopepoda – copepodsMalacostraca – shrimp, lobster, crabs

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Video

Some common crustaceans

Rock lobster

Sub-phylumCrustacea

ClassMalacostraca

OrderDecapoda

Copepod

Sub-phylum ClassCrustacea Copepoda

Order Harpacticoida

Photos:

NO

AA

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Phylum Echinodermata: The ocean’s stars ● Include sea stars (starfish),

sea urchins, sand dollars and sea cucumbers

● Most echinoderms have these traits:– Tube feet for motion– Radial symmetry (adults)

● Symmetry around a single point

– A water vascular system that circulates seawater

Echinoderm TaxonomySome Common ClassesKingdomAnimalia

PhylumEchinodermata

ClassesAsteroidea – sea starsOphiuroidea – brittle starsHolothuroidea – sea cucumbersEchinoidea – sea urchins

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Video

Some Echinoderms

Sunflower star

PhylumEchinodermata

ClassAsteroidea

OrderForcipulatida

Source:

NO

AA

Sea urchin

Phylum ClassEchinodermata Echinoidea

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Deep Sea Sampling Techniques

● To figure out what types of organisms make up communities like the sample we just saw (and how many of each type there are), scientists use a process called sampling

● In today’s activity, we will simulate different types of sampling methods to explore the variety of invertebrates in the ocean

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A1 - Sampling Groups

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A2 - Sampling Groups

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A3 - Sampling Groups

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