mollusca Flashcards
Mollusca
means “soft body”
tube used to take in water (oxygen) and food.
siphon
meaning of Gastropoda
stomach foot
meaning of cephalopoda
head-foot
tissue that secretes a shell
mantle
Blood circulation is of this design
an open circulatory system
tongue-like structure with tiny bone plates
radula
type of circulation seen in this group
a closed circulatory system
structure used for locomotion
a foot
This structure can be made into an anchor or extended. by diverting blood into a particular sinus
foot
this structure produces a lubricating slime to aid in movement
the foot
feature that is highly evolved and approaches that of mammals in ability
the eyes
material shells are made of
calcium carbonate
gametes are spread into the water for fertilization and possible distribution
broadcast fertilization
term for organisms like snails which possess both gametes for fertilization
hermaphridite
the foot has specialized into these structures
what are arms and tentacles
larval type shared with annelids
trochophore larva
structure used for gas exchange
gills
sensory structures found on snails
light sensitive eyes and antennae
highly developed system in active predator, relative to that seen in a clam or a snail
nervous system
class Mollusca
includes
- class bivalvia (clams and oysters)
- class Gastropoda (snails and slugs)
- class Cephalopoda (octopus and squid)
all members of Mollusca must have
- mantle
- tissues that secretes shell material, calcium carbonate H20 out of siphon - Muscular Foot
- locomotary or clinging foot - Soft-bodied
Class Bivalvia (2 valves) (clams, oysters, mussels)
- sessile
- filter feeders
- range of habitats due to siphon and shell
- open circulatory system with 2 chambered heart
Class bivalvia siphon and shells
- siphon (double tube) take in food and oxygen get rid of waste and CO2
- shell 2 part shell, closes tightly and retain water necessary for survival
class bivalvia circulatory system
Open circulatory system with 2 chambered heart
§ Blood delivered to sinuses (chambers) in tissues
§ Soaks tissues delivering oxygen and
removing carbon dioxide
§ Blood can be withheld in a sinus, causing
tissue to swell up
clams foot
can be extended and used as an anchor to aid in movement
bivalvia are sessile animals
- they broadcast gametes into water for distribution and possible fertilization
- trocophorelarva (similar to Annelids) develops from zygote
- gills exchange gases with water drawn in through siphon
bivalvia digestive tract
- simple,short
- undigested material released through anus back into water via siphon
- nephridia, removes metabolic waste-localized to one region
bivalvia nervous system
- not highly specialized due to sessile slow moving lifestyle
- brain area + nerve cords operate foot and siphon
Class Gastropoda (stomach foot) (snails, shells) (Slug, no shell)
- snail mantle located around open edge of shell
- Foot: compromises soft tissue mass on ventral surface
- muscular undulations allow slow movement
- slime acts as a lubricant when crawling
- radula (tongue-like structure with bony plates) for feeding
Class Gastrapoda are what
- hermaphroditic (annelids, exchange sperm between reproductive organs on ventral surface)
- fertilization occurs later; eggs deposited in damp places
class Gastropoda nervous system
- light sensitive “eyes” on retractable antennae
- cephalized with distinct head region
- 2 chambered hearts
- open circulatory
Class Cephalopoda (head foot) (squid, cuttlefish, octopus, nautilus.)
- Most highly evolved/specialized members of phylum
- hunters noted for subdivided foot, large heads, well-developed nervous systems and move quickly
- closed circulatory system
- zoom zoom fast
- Efficient swimmers, move by jet propulsion water is forced out of siphon
class cephalopoda eye
-similar ability to learn and behave in a complex manner
LOOK AT MOLLUSCA SIAGRAMS
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