1. 15D – Other Invertebrates
Page 468 – 473

2. Phylum Mollusca 2nd largest animal phylum 3 Classes Class Bivalvia
Class Gastropoda
Class Cephalopoda

3. Phylum Mollusca Octopus, oysters, snails, slugs, squid, clams
All Mollusca have the following:
Mantle: protects the organs (insides); helps it breathe
Shell: hard outer covering; protects the body
Visceral Hump: holds the heart, stomach, and excretory organs (where it pees and poops)
Foot: allows it to move
Radula: organ with small teeth that grabs food and pulls the food into the mouth
Babies are called trochophore

4. Phylum Mollusca

5. Class Bivalvia Oysters, clams, mussels, and scallops
This class has a shell with two halves
Called “filter feeders” because they pull in water and eat the smaller animals out of the water
Water is pulled in and pushed back out by siphons – these work like straws
Gills allow Class Bivalvia to breathe
These are usually sessile (don’t move) with 2 external (outside the animal) shells

6. Class Bivalvia

7. Class Gastropoda
Called Stomach-footed mollusks because they have their foot under their visceral hump
Snails, slugs, nudibranches
Usually move by crawling
Usually have one external shell (not slugs)
Usually have a mantle cavity: a space between the shell and the body that acts as a lung

8. Class Gastropoda

9. Class Cephalopoda
Octopus and squid – the foot is divided into arms with suckers that are used to catch food
Called head-footed mollusks because their foot is under their head
They live in the ocean and swim

10. Class Cephalopoda

11. Phylum Echinodermata
Sea urchins, starfish, sand dollars, sea cucumbers, brittle stars, basket stars, sea lilies, and feather stars
Live in the ocean
They have an endoskeleton called ossicles
They have radial symmetry
They have a water-vascular system: they pull water into themselves in order to change water pressure around them and work the suction cups on their arms

12. Phylum Echinodermata

13. Class Asteroida Starfish
Tube feet are the suction cups inside of the rays (arms) that help the starfish grab food and move
They regenerate (if you cut a part off, it will grow back)

14. Class Asteroida

15. Class Enchinoidea Sea Urchins and Sand Dollars
They have spines that protect them
They are scavengers: they will eat anything

16. Class Enchinoidea

17. Class Holothuroidea Sea Cucumbers
They are slow-moving and eat whatever they can trap
When they are attacked, they throw out their internal organs and run away, then regenerate (make) new organs

18. Class Holothuroidea

19. Class Ophiuroidea Brittle Stars and Basket Stars
Brittle stars throw away their arms when they are attacked, then regenerate their arms
Basket Stars eat at night – they raise their arms to make a basket shape to trap small animals and eat them

20. Class Ophiuroidea

21. Class Crinoidea Sea Lilies and Feather Stars
Sea lilies are sessile (don’t move)
Feather stars are able to crawl slowly

22. Class Crinoidea