Phylum Mollusca Intro Notes

notes on phylum Mollusca

1. Phylum MolluscaPhylum Mollusca
By Mr. “AFC North Champs” ChapmanBy Mr. “AFC North Champs” Chapman

2. Phylum: MolluscaPhylum: Mollusca
The Soft-bodied AnimalsThe Soft-bodied Animals

3. Phylum: MolluscaPhylum: Mollusca
•Has about 100,000 speciesHas about 100,000 species
•Bilateral symmetry and TriploblasticBilateral symmetry and Triploblastic
•Mollusk bodies have three regionsMollusk bodies have three regions
–Head-footHead-foot
–Visceral massVisceral mass
–mantlemantle

4. Body RegionsBody Regions
•Head-FootHead-Foot – is elongated with an anterior head, – is elongated with an anterior head,
containing the mouth and certain nervous and containing the mouth and certain nervous and
sensory structures, and an elongate foot used for sensory structures, and an elongate foot used for
attachment and locomotion.attachment and locomotion.

5. Body RegionsBody Regions
•Visceral MassVisceral Mass – the area that contains the organs – the area that contains the organs
of digestion, circulation, reproduction, and of digestion, circulation, reproduction, and
excretion and is positioned above the head-foot.excretion and is positioned above the head-foot.

6. Body RegionsBody Regions
•MantleMantle – is attaches to the visceral mass surrounds – is attaches to the visceral mass surrounds
the body and secretes the calcareous shell the body and secretes the calcareous shell
(limestone).(limestone).

7. CharacteristicsCharacteristics
•Mantle cavity functions inMantle cavity functions in::
–ExcretionExcretion
–Gas exchangeGas exchange
–Elimination of digestive Elimination of digestive
wasteswastes
–Release of reproductive Release of reproductive
productsproducts

8. CharacteristicsCharacteristics
•RadulaRadula
–Is a rough structure on Is a rough structure on
the tonguethe tongue
–Contains rows of curved Contains rows of curved
teeth teeth
•Open circulatory systemOpen circulatory system
–Except CephalopodesExcept Cephalopodes
•CoelomCoelom

10. Important WordsImportant Words
•DeuterostomesDeuterostomes – is when the anus develops – is when the anus develops
before the mouthbefore the mouth
•ProtostomesProtostomes – is when the mouth develops – is when the mouth develops
before the anusbefore the anus

11. ClassesClasses
•There are 8 classes, but only three that are important There are 8 classes, but only three that are important
to us.to us.
•Class: Gastropoda “Stomach Foot”Class: Gastropoda “Stomach Foot”
–Snails and slugsSnails and slugs

13. ClassesClasses
•Class: Bivalvia “2 valves (shells)”Class: Bivalvia “2 valves (shells)”
–Mussels, clams, oystersMussels, clams, oysters

15. ClassesClasses
•Class: Cephalopoda “Head Foot”Class: Cephalopoda “Head Foot”
–Squids, octupus, nautilus, cuttlefishSquids, octupus, nautilus, cuttlefish

17. THE
END