echinodermata spiny skinned. echinoderms *6000 living species 20,000 extinct species *all oceans,...

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Echinodermata Spiny Skinned

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Page 1: Echinodermata Spiny Skinned. Echinoderms *6000 living species 20,000 extinct species *all oceans, all depths *Planktonic larvae - bilateral symmetry *adult

Echinodermata

Spiny Skinned

Page 2: Echinodermata Spiny Skinned. Echinoderms *6000 living species 20,000 extinct species *all oceans, all depths *Planktonic larvae - bilateral symmetry *adult

Echinoderms* 6000 living species 20,000 extinct species

* all oceans, all depths

* Planktonic larvae - bilateral symmetry

* adult - pentamerous radial symmetry

* sexual external fertilization

* lack a head therefore have oral & aboral surfaces

* endoskeleton

* water vascular system *** only in echinoderms***

* tube feet and ampullae

* madreporite

Page 3: Echinodermata Spiny Skinned. Echinoderms *6000 living species 20,000 extinct species *all oceans, all depths *Planktonic larvae - bilateral symmetry *adult

vocabulary

• Water vascular system - network of water filled canals

• tube feet - muscular sacs that extend outside the body opposite ampullae. Used for attachment and locomotion

• madreporite - a porous plate on the aboral surface, connects water vascular system to the exterior

Page 4: Echinodermata Spiny Skinned. Echinoderms *6000 living species 20,000 extinct species *all oceans, all depths *Planktonic larvae - bilateral symmetry *adult

The 5 classes of Echinodermata

Phylum Echinodermata

Class Asteroidea

ClassOphiuroidea

Class Echinoidae

Class Holothuroidae

ClassCrinoidae

Page 5: Echinodermata Spiny Skinned. Echinoderms *6000 living species 20,000 extinct species *all oceans, all depths *Planktonic larvae - bilateral symmetry *adult

Asteroidea• Usually 5 arms, up to 50 arms

• Ambulacral groove - radiating channels on each arm, has hundreds of tube feet

• Pedicellariae - minute pincher like organs that help keep surface clean

• What do they eat? Snails, barnacles, bivalve, etc.

• How do they eat? Project their stomach into soft body of prey, partial external digestion

• EX. Sea Stars or Starfish Previous Slide

Page 6: Echinodermata Spiny Skinned. Echinoderms *6000 living species 20,000 extinct species *all oceans, all depths *Planktonic larvae - bilateral symmetry *adult

Ophiuroidea

• 2,000 species

• What do they eat? Organic material

• Arms are long thin and very flexible.

• Arms lack suckers on tube feet. They are not used for locomotion but for feeding and sensory.

• EX. Basket stars, Brittle stars and sea serpents

Previous Slide

Page 7: Echinodermata Spiny Skinned. Echinoderms *6000 living species 20,000 extinct species *all oceans, all depths *Planktonic larvae - bilateral symmetry *adult

Echinoidea• Rigid test with movable

spines and pedicellariae

• Arms moved up to meet at the top

• Now ambulacral grooves extend from top to bottom

• What do they eat? Plant material, encrusting animals, dead organic matter

• Aristotle’s lantern - jaws and muscles

• EX sea urchins and sand dollars

Previous Slide

Page 8: Echinodermata Spiny Skinned. Echinoderms *6000 living species 20,000 extinct species *all oceans, all depths *Planktonic larvae - bilateral symmetry *adult

Holothuroidea• Elongated body

symmetry

• Endoskeleton: microscopic calcareous spicules throughout watery skin

• 5 rows of tube feet from mouth to anus

• Evisceration - sudden expulsion of gut and other internal organs

• EX. Sea cucumbers Previous Slide

Page 9: Echinodermata Spiny Skinned. Echinoderms *6000 living species 20,000 extinct species *all oceans, all depths *Planktonic larvae - bilateral symmetry *adult

Crinoidea

• 600 species• 5 to 200 arms • Mouth is located on

the ventral surface• mucus • filter feeders• EX. Sea lilies, Feather

stars

Previous Slide