Molluska Flashcards
Invertabrae
No spine
Molluscus
Soft bodied
Shell
External or internal
Types of molluskus I
Snail Slug Clam oysters Squids Octopi
Free swimming larvae
Trochophore
How long have they been around
550 million
Form and function
Coelom
Complex organ system
Body plan ( 4 parts )
Foot
Mantle
Shell
Visceral mass
Foot
Flat shaped for crawling
Spade snap for burrowing
Tentacles for catching prey
Mantle
Thin layer of tissue
Covers the body
Shell
Made by glands in mantle
Secretes calcium carbonate
Some shed it
Visceral mass
Consists of internal organs
Feeding
Herbivores Filter feeders Carnivores Parasites Detritivores
Detritivores
Feed on organic waste
Radula
On snails abs and slugs
Flexible tong shaped structure
Teeth attached
Herbivores
Scrape algae
Carnivores
Drill through shells tear tissues of prey
How do some octopi kill prey
Toxins that paralyze
Clams and oysters feed
Filter feeders using feathery gills
Siphon
Tube like structure where water enters and leaves body
Directs water over gills which captures plankton
Cilia
In squids
Used to move food in mouth
Respirating aquatic mollusks
Gills in mantle cavity
Land snails respire
Surface area of mantle cavity lined woth blood vessels
Gases diffuse along surface area
Must be moist
Circulation
Pigeon and nutrients carried via closed or open circuit
Open circulatory system
Simple heart Blood leaves vessels to fill sinuses Blood passes from sinuses to gills for gas exchange Returns to heart For slow animals
Sinuses
Sac like spaces
Closed circulatory system
Blood ponies through but day through vessels
Never leaves blood vessels
Excretion
Cells release nitrogen containing wastes into blood
Nephridia
Remove ammonia from blood to be released out of body
Simple nervous system
Clams and bivalves Small ganglia near mouth Few nerve cords Simple sense organs Chemical receptors Eyespots
Complex nervous system
Octopi have highly developed brains
Most developed of all organisms
Movement snails
Crawl using foot
Movement octopi
Jet propulsion form water drawn into mantle cavity and forced through siphon
Snails and bivalves reproduction
Sexually release sperm into water woth eggs externally
Eggs go into free swimming larvae
Tentacle mollusks and some snails reproduction
Internal fertilization
Some are hermaphrodite
Groups of mollusks
Gastropoda
Bivalves
Cephalopods
Gastropoda
Shell less or single shell Moves via Foot on central side Ex pond snails Land slugs Sea hats Sea butterflies Nudibramch
Bivalves
Food group 2 shells held together with muscle Ex: clam oyster Mussels scallops sedentary Filter feeders
Cephalopods
Octopi squids cuttle fish nautiluses
Soft bodied head stretched to single foot
Foot divided into tentacles with suckers
Small i tern always shell except for mautiluses
Octopi have no shell
Nautiluses
Do not have suckers bit sticky mucus covering.
How long have cephalopods been around
500 million years
Mollusks
Detritus filter algae form ware
Bio remediation
Medical application for finding cure
