Mollusca Flashcards
What is the role of the apical tuft?
Used to keep the trochophore larva upright
What are the two apomorphies of the mollusca?
Schizoceol, and metanephridia filtering coelomic fluid
2. dorsal heart and pericardial cavity
What is the role of ceolomic fluid?
transport fluid
What is the metanephridia?
An excretory gland used for the mollusca
Describe how the metanephridia works?
Fluid is pulled in through the nephrostome, nutrients were pulled out the top, the nitro waste is filtered in the bottom, and excreted through the nephridiopore
Define adaptive radiation
Taxa of animals that are all related, but vastly different body plans
What is a radula?
a chitinous band of small teeth used to break up food for consumption
What is the radula located on?
on top of the odontophore (tongue)
Define tetraneural nervous system
Has four nerve cords
What is the ctenidium
Molusc version of the lung/gill
What is the pericardial cavity?
Area and layer surrounding the heart
What is another role of the metanephridia
Passing sperm
What is the hemocoel?
Open part of the circulatory system, where the organs are located. Bathes organs in blood
Where does the veliger get its name from?
Velum
What group of mollusca have 8 chitin shells?
Polycophora
Define periostracum
Outer layer, doesnt dissolve in acid
Define Prismatic layer
Makes up bulk of shell, made of calcium,
Define Nacreous layer
Made of mother of pearl, very smooth
Mollusc clam edge…
Trilobe
Role of crystaline style
attached to particulate mucous, spins to bring the mucous down to grind against the gastric shield
What is the role of gastric shield?
crystaline style rubs against it, causing the mucous be ground down, nutrients extracted to ciliated storage area
Digestive glands?
They sort only certain food particles to move on and get absorbed
What is the result of torsion in snails?
They shift mantel cavity to the front, and the anus is now above their head
What are two advantages of torsion?
- Crossed retractor muscles now pull head and posterior into shell quickly
- By placing mantle cavity and water sensing organs at the front fo the animal, we are able to test the water in front of you
What is the impact of taking the dart
You become more female in order to take sperm
The snails are squished for room. Some organs combine, such as…
sperm duct and oviduct are the same.
Ovaries and testes are the same gland, called ovotestis
