Coelomate Invertebrates Flashcards
Coelomates have a body design that:
- repositions body fluid
- allows complex tissues/organs to develop
- allows larger body size
What is second in diversity?
mollusks
How are mollusks diverse?
- wide variety in sizes and body forms
- different environments
What animals make up mollusks?
snails, slugs, clams, octopuses, and others
How are mollusks important to humans?
important food source
What are 4 classes of Mollusks?
- Polyplacophora
- Gastropoda
- Bivalvia
- Cephalopoda
What does the name Polyplacophora mean?
many plates
What does the name Gastropoda mean?
stomach foot
What does the name Bivalvia mean?
two shells
What does the name Cephalopdoa mean?
head foot
What is the phylum name for Mollusks?
Mollusca
What type of symmetry do mollusks have?
bilaterall
What is reduced in mollusks? What does it surround?
they have a reduced coelom surrounding the heart and excretory organs
Where are organs located in mollusks?
visceral mass
What is a visceral mass?
core parts of animal’s body where organs are located
How are mollusks’ head?
may have a differentiated head at the anterior end of the body
What allows for complex organisms?
having a coelomic cavity
What covers the Mollusks body?
mantle
What is a mantle?
a thick epidermis that covers the dorsal side of the body that houses organs
What organs does the mantle house?
respiratory, excretory, reproductive, and digestive
What respiratory organs do aquatic mollusks have?
ctenidia (gills)
What is the function of the foot of a mollusk?
locomotion, attachment, and food capture (not all use it for food capture)
What is the shell of a mollusk secreted from?
mantle tissue
Do all mollusks have an exterior shell?
no, some have interior and some have none at all
What are shells made of?
calcium, carbonate rich
What is the function of a shell?
protection
How do mollusks remove waste?
Nephridia
What is nephridia?
special excretory structures that remove nitrogenous wastes
What type of circulatory system do mollusks have?
all except Cephalopods have an open circulatory system, they have a closed
What is an open circulatory system?
-blood is contained in connected chambers surrounding various organs instead of within blood vessels
What is a closed circulatory system?
blood is contained within the blood vessels
What allows cephalopods to move fast?
efficiency of a closed circulatory system
What allows organisms to be large?
closed circulatory system
Are mollusks sex separated or hermaphroditic?
distinct male and female individuals in most
What type of fertilization do mollusks do?
external
What are mollusk larvae like?
free-swimming
What animal are class Polyplacophora?
Chitons
What do Polyplacophora look like?
oval bodies, eight overlapping dorsal calcareous plates
Are Polyplacophora segmented?
no
What diet do Polyplacophora have?
grazing herbivores
How do Polyplacophora plates move?
having multiple plates allows the body to curve to match rock
What is the function of the shell of Polyplacophora?
protects the Chiton from drying out when exposed to dry air
What are the “teeth” of Polyplacophora called?
radula, used for scraping
What animal are class Gastropoda?
snails and slugs
What are Gastropoda eyes like?
tentacles with eyes
Can Gastropods see?
can see images (not well)
How do snails embryologically develop?
- torsion
- coiling
What is torsion?
mantle and anus cavity move from the posterior to the front because it rotates during embryonic development (counter clockwise rotation)
What is coiling?
spiral winding of the shell
What animals are under class Bivalvia?
clams, scallops, mussels, oysters, and others
What is the body of a Bivalvia like?
2 lateral (right and left) shells (valves) hinged together dorsally
How do Bivalves eat?
sessile filter-feeders, siphon water across gills
What does sessile mean?
fixed in one place
Do Bivalvia move?
some can. Clams can dig with foot and move on sand, all move as larvae
Are Cephalopods prey or predators?
active marine predators
What do Cephalopods body look like?
series of arms with suction cups
How are Cephalopods advanced?
have highly developed nervous system
How is the Cephalopod nervous system highly developed?
they exhibit complex patterns of behavior and high level of intelligence
