1. Marine Sciences 2nd semester 1st quarter
Phylum Mollusca

2. Vocabulary Acid (acidic) Hydrologic cycle Veliger Base (basic
Hypersaline
Nephridia
Brackish
Ion
Cerata
Buffer PH
Siphon
Condense
Thermocline
Chromatophores
Crystallization
Water vapor
Sepia
Desalination
Mantle
Colemates
Distillation
Foot
Protostomes
Evaporate
Radula
POLYPLACOPHORES
Filtration
Trochophore

3. Phylum Mollusca Molluscas Marine, some freshwater and/or terrestrial
Phylum Mollusca
Molluscas
Marine, some freshwater and/or terrestrial
Coelomates – body cavity fully lined with mesoderm
Protostomes – first embryonic opening  mouth
The Mollusks range from squid and octopuses
Snails , sea slugs (snails without shells) , oysters, clams and Conches

4. Who is in Phylum Mollusca
All Mollusca have
Ventral, muscular foot
Radula
Mantle (secretes shell, when present)

5. The Mantle Is a muscular bag that surrounds the gills and most organs
It’s used to circulate the water through the the organism.
Some use it for feeding some use it for propulsion
Secrets the calcium carbonate shell

6. Muscular Foot It’s located beneath the head
Slugs and snails use foot to crawl
In other mollusk for example like squids the foot becomes the tentacles
Geoduck

7. Radula Think of it as tongue bearing rough scraping teeth.
Different types of mollusk have different types of radula
In cone snails the radula takes the form of a harpoon with barb and venom that paralyzes.

8. The Six Classes of Mollusks
Class Gastropoda
Class Cephalopoda
Class Polyplacophora
Class Bivalvia
Class Monoplacophores
Class Scaphopods

9. Monoplacophores and Polyplacophores
Also emerging at the same time as gastropods, these shells all live on seabeds and only reach about an inch in total length.
POLYPLACOPHORES
Emerging 500 million years ago, polyplacophores (aka chitons) live a few inches below the water's surface on reefs. Their shells consist of eight tiny plates layered as shingles with pores

10. SCAPHOPODS
these shells washed up on beaches around the world. They are small, curved, white tubes formed for specialization purposes. There maximum length is five inches and they tend to be white in color

11. GASTROPODA
These shells emerged 600 million years ago. No other class has as many species (more than 50,000) or are as widely collected
Marine, freshwater and terrestrial herbivores
Shell is coiled (if present)
Body symmetry is distorted by torsion
Many have single organs gills and nephridia (simple kidneys)
Ex. Snails

12. Gastropods that lack shell
Subclass Opisthobranchia
Slugs, sea slugs, and nudibranchs
Some have spines with toxins
Some feed on cnidarians and have the ability to eat the nematocysts without firing or digesting them.
Nematocysts are incorporated into cerata on the nudibranch’s back
Cerata are unique organs that look like soft tufts and serve both as gills and defensive weapons armed with stolen nematocysts

13. Class Bivalvia Mollusks that have two hinged shells
Marine and freshwater sessile filter feeders
Lack a head like other mollusks
Mantle acts like pump water into the organism for oxygen
Commercial pearl fisherman
Ex. Clams, mussels, oysters and scallops

14. Bivalves are important
Why are bivalves important
Provide habitat , shelter
Ecosystem engineer, and a foundation specie
Are a food source for various organism
Help in filtration of the water
Shoreline protection
Important commercial specie

15. Filter Feeders

16. CEPHALOPODS
Emerging about 525 million years ago, these shells are the most evolved of all six classes and the mollusks are carnivorous.
Their shells appear as an "outer hull", but are more commonly internal.
There are about 600 of these living species today and, including the giant squid, they may reach lengths of 65 feet

17. CEPHALOPODS Marine; active predators
Possess tentacles for prey capture
Have little or no shell
Foot became arms
Specialized foot known as siphon - which enables them to move
Chromatophores – pigment sacs in their skin cells that allow them to change color
Sapia black ink sac
Have eyes and nervous system
Ex. Octopi, squid, cuttlefish & nautili

18. INK

19. Shape shifter

20. Dissection Tools

21. Oyster Anatomy

22. Good Oyster Vs. Bad Oyster

23. Oyster Life cycle Veliger – planktonic larval stage of mollusks
Trochophore –Initial larval stage of mollusks

24. Dissection

25. Oyster Lab
Make sure you clean up after the lab if not you will have negative points deducted from you
Rinse all the tools off then place them in tray
Place waste in the designated container
Turn in Lab before you leave
Remember Lab is worth as much a test grade so take it serious