Gastropoda Flashcards
What process do gastropods undergo as larvae that other molluscs do not?
Torsion.
Benefits of torsion.
Moves the gills and sensory organs (Osphradia) to the anterior of the body.
Center mass of shell over head-foot.
Defense for larvae.
Characteristics of Archaeogastropods.
a. Two gills
b. two inhalant and one exhalant
c. grazers
d. high energy environments
e. may have nacre
Which grade of gastropod has a selenizone notch?
Archaeogastropods.
Characteristics of Mesogastropods.
a. One gill
b. no selenizone/trema/siphonal canal
c. one inhalant and one exhalant
d. no nacre.
e. round-oval shaped aperture.
f. grazers, suspension, predation
Which type of mesogastropod is known for being the fastest gastropod and highly predatory?
Moon snails. Capture prey with foot and use radula to drill into shell into prey.
Characteristics of Neogastropods.
a. one gill
b. one inhalant (siphon) and one exhalant (posterior)
c. siphonal canal
d. elongate shell
e. hard and soft substrates
f. predatory and scavengers
What does MMR stand for and what is its significance?
Mesozoic Marine Revolution. Explosion of plankton diversity. Leads to major changes in food chain and ecosystems. Leads to new predators and predatory strategies as well as protection strategies.
How are shells typically preserved?
Most commonly preserved as casts or moulds. Most are aragonitic, do not usually preserve well.
what is the operculum?
An aperture door, allows for protection when head-foot mass retreats into shell.
