Mollusks Flashcards
soft body
occupy a great range of habitats
mollusk body plan has a head-foot portion and a visceral mass portion
Phylum mullusca
depends primarily on muscular action for its function
more active area, containing: Feeding
Cephalic sensory Locomotor organs
Heed foot portion
portion containing digestive, circulatory, respiratory, and reproductive organs
depends primarily on ciliary tracts for its functioning.
Visceral mass
Have valves or plates for protection
Have gills lining the sides of their body
Dorsoventrally flat with foot used as a “suction cup”
Lives on rocky areas on the beach
Undergoes metamorphosis Free-swimming larval stage More sessile adult stage
Class polyplacophora
Have tusk-like shells
Foot specialized for digging in the substrate
(either sand or mud)
Found in the subtidal zone (underwater)
Have two openings: bigger opening is where the foot and tentacles emerge; smaller one used to relieve pr
Class scaphopoda
Tentacles used as feelers and for grabbing food; food particles will be shred by the radula found inside the shell
Undergoes metamorphosis Free-swimming larval stage More sessile adult stage
Class scaphopoda
Pronounced muscular foot
Gastropoda
used for respiration (sucking in water)
Siphon
maintenance (sucking air or releasing air to stay afloat or to sink)
Buoyancy
Have radula (rows of teeth)
For protection against environmental conditions (e.g. lack of water)
For protection against predators
Gastropoda
Has an that closes the
aperture/opening of the shell
operculum
Eyes are usually rudimentary;
Light and dark
Gastropoda
Have two shells connected on a hinge Have foot specialized for digging or
pushing the substrate
Siphons used to suck water and food particles in
Have nacre: a shiny substance used to coat irritants and infected internal parts; creates pearl
Class bivalvia
Most living members do not have external shells (except for nautilus)
Shells are reduced as an internal, plastic-like structure
Have well-developed eyes
Have well-developed nervous syste
Cephalopoda
