Phylum Mollusca Chapter 16 study guide questions Flashcards
16.1 Name the higher order Clades that Phylum Mollusca belongs to.
Clade Protosomia
Clade Bilateria
Clade Lophotrochozoa
16.2 What are three synapomorphies that define Phylum Mollusca
Radula
Mantle
Muscular foot
General Features of Phylum Mollusca
Bilateral symmetry
Complete gut
True coelom
Coelom reduced to a hemocoel
Sexual reproduction
Open circulatory system
Excretion via Metanephridia (type of ‘kidney’)
Hemocoel
main coelomic cavity later fuses with the blastocoel to form a new cavity
blastocoel- fluid-filled space in a blastula
Body features of Phylum Mollusca
Head-foot
-radula
-muscular foot
Visceral mass
-Mantle
-mantle cavity
-Viscera
-Metanephridia
radula
feeding
muscular foot
locomotor
Visceral mass
organs
Mantle and Mantle cavity
-secrete shell & protect viscera
-space for H2O circulation; house
gills or lung; exit for waste & gametes
Viscera
Digestive, circulatory, excretory,
reproductive organs
Metanephridia
excretory organ (nitrogenous waste)
Gills where are they and what do they do
In the mantle cavity and are used for breathing
Class Polyplacophora
synapomorphy and type of Mollusca
Synapomorphies:
- Shell with 7 - 8 overlapping plates
- Mantle cavity along sides of foot
- Multiple gills
Type of mollusca
-Chitons
Class Gastropoda
synapomorphy and type of Mollusca
Synapomorphy = torsion
Includes whelks, conchs,
limpets, snails, slugs
Class Bivalvia
synapomorphy and type of Mollusca
Synapomorphies:
– Bivalve shell
– Loss of radula
Clams, mussels,
scallops, oysters,
shipworms
