Mollusca Flashcards
Mollusca habitat?
marine, freshwater and terrestrial
Mollusca symmetry?
Bilaterally Symmetrical or asymmetrical
Mollusca body cavity?
Body cavity is limited around the heart (true coelom)
Mollusca embryonic layer?
Triploblastic
Mollusc are Monoecious or Dioecious?
Many are dioecious, but some are monoecious
Mollusc have A_______ T______ Larva
Ancestral trochophore larva (free swimming)
Trochophore larva develops into?
Veliger Larva (free-swimming)
Between mantle and visceral mass is a ________
Mantle cavity
What can be found in the mantle cavity?
Gills and lungs
What do mantle cavity produce?
Calcium carbonate (CaCO3)
What do bivalves use for locomotion?
Muscular foot
Mollusc circulatory system?
Open circulatory system (except for Cephalopoda)
Mollusc excretion through kidneys called
metanephridia
Mollusc Respiration through?
Ctenidia (marine) lungs (terrestrial)
organ for mechanical food
processing or rasping?
Radula
Radula is present in all class except?
Bivalves
Radula is supported by a cartilage which moves in and out the buccal cavity is called
odontophore
What is the largest, most successful, most diverse class?
Gastropoda
All living gastropods have undergone unique process of __________
Torsion
What is torsion?
the rotation of the visceral mass, mantle, and shell 180˚ counterclockwise with respect to the head and foot of the gastropod. This rotation brings the mantle cavity and the anus to an anterior position above the head.
Gastropods have _______ body
Asymmetrical
Gastropods shell are usually _______
coiled or uncoiled
Right handed coil is called?
Dextral
Left handed coil is called?
Sinistral
Gastropods have a ____________ head
Well-developed
Smallest, oldest whorl
Apex
opening of shell. Where foot will exit
Aperture
“trapdoor” to close the aperture of the shell when the soft parts of the animal are retracted
Operculum
Many snails possess a ________, a snorkel that sticks out into the water through a _________, seen in the ________ in the shell. They use the siphon to bring water in over their gills and also to taste the water.
Siphon, siphon cannal, aperture
central axis where the whorl spiral around
Columella
In gastropods, lung open to the outside by a small opening (pore) called _________
Pneumostome
Located at the base of the incurrent siphon of gastropods is a sensory area called ________. Which is a ________ or ________
Osphradium, chemosensor, mechanoreceptor
Gastropods are Monoecious or Dioecious?
Monoecious / Dioecious
Larva of gastrapods are?
Veliger larva
Bivalves habitat?
Mostly marine, others are in brackish or freshwater
Function of valves in bivalves?
a firm exoskeleton that protects the body and provide muscle attachment
Bivalves symmetry?
Bilaterally Symmetrical
swollen hump; oldest and thickest
part of the shell in bivalves
Umbo
surrounds the umbo.
concentric lines of growth
Bivalves feeding habit?
sedentary filter feeders
valves are attached together by the
_____________ on the ________ side. _______ side is free to allow the protrusion of the foot
hinge ligament, dorsal, ventral
outer, rigid, and horny layer of the bivalves shell; it protects the underlying CaCO3 from dissolving by acids in the waters.
Periostracum
inner, shiny layer in bivalves that lies next to the mantle which is secreted continuously by the mantle surface
Nacreous layer
Bivalves has no _____, no ______, and little ________
Head, radula, Cephalization
serves as a spring. separates the two
valves
Hinge ligament
pulls the shell closed
anterior & posterior adductor muscles
allows cyclic water flow throughout the mantle cavity
incurrent & excurrent apertures
surrounds the entire viscera. And upon lifting, exposes the outer gills
Mantle layer
Gills function in bivalves?
allows continuous water flow through
the mantle cavity
helps in gathering food material
In female bivalves, the ______ gill is thicker than the ______ gill. The former serves as a ___________ for offspring
Outer, inner, brood chamber
Muscular foot of bivalves function?
For locomotion and anchoring (pumps blood into the foot, causes it to swell and anchor itself on soft surfaces)
Gastropods have a ________ head where its eyes are on __________
Distinct, a pair of tentacles.
Which aids gastropods in locomotion? present _________ the mouth
mucous glands, beneath
In gastropoda, its visceral mass that is coiled inside the shell. it is covered by a thin mantle. thickens to form the collar
contains most of the organs, including a complete digestive and excretory tract as well as the reproductive organs
Visceral hump
responsible for secreting the shell in gastropoda
Collar
topmost, oldest, and smallest whorl in gastropoda
Apex
comprise the spire
Whorl
Cephalopoda are prey or predator?
Predator
Habitat of Cephalopoda?
All are marine
Cephalopoda are Monoecious or Dioecious?
Dioecious
Does Cephalopoda have a larval stage?
No. Eggs hatches as juveniles
Cephalopoda have _________ eyes. That are similar to ________. And are _________ and ________
2 conspicuous, vertebrates, highly complex and advanced
Cephalopoda have how many arms and tentacles?
8 arms. 2 tentacles
4th pair of arms in Cephalopoda are long ___________
Retractile tentacles
Tentacles and arms of Cephalopoda are merged in the ______ region
Head
In Cephalopoda, expels water from the mantle cavity and allows it to move swiftly
Funnel
Function of siphon in Cephalopoda?
Excrete waste, sexual product, and ink
Siphon is a derivative of______
Foot
Male arms in Cephalopoda are _________ and _________
Longer and thicker
In Cephalopoda, it is a process that allows the 4th arm of the mature male to become modified for the transfer of sperm cells to the female
hectocotyly
In Cephalopoda, it is surrounded by a buccal membrane with seven projections
Mouth
The pen in Cephalopoda is composed of?
Chitin
In Cephalopoda, it causes spotted
skin, also known as pigment cells, which allows it to change color
chromatophores
In gastropods, first-half turn of the spiral contains the _________
Highly vascular portion (serves as respiratory chamber; lungs)
In gastropods, second-half turn contains ________ and ________
Heart and a large kidney
