Feeding/Digestion
True or False: Bivalves are considered active predators
false they are filter feeders
What does "mollusca" mean?
soft bodied
What is the biggest threat to ocean dwelling molluscs?
climate change
What class is mostly eaten by humans?
Bivalves
True or false: Bivalves use internal fertilization
false (external)
Which class are considered active predators?
Cephalopoda
What is the largest class of molluscs with over 65k species?
Gastropoda
What ecosystem impact do bivalves have?
water filtration
Mollusks were traded amongst humans and used as....
currency
Put the 3 classes in order from least to most complex nervous system
bivalves, gastropods, cephalopods
What is the body part gastropods use to scrape algae off of rocks?
Radula
What is the only class that can be found in both freshwater and saltwater environments?
bivalves
How do gastropods impact ecosystems by being herbivores?
controlling algae blooms
What is the name of the most venomous octopus?
blue ringed octopus
What do land dwelling gastropods use for respiration?
pneumostome
What's the difference between arms and tentacles in cephalopods?
Arms have suckers down the entire length and are shorter and thicker than tentacles which only have suckers at the end and are longer and thinner.
Give 4 examples of animals in the class "Bivalvia"
clams, oysters, mussels, scallops
What role do cephalopods play in food webs?
Predators of other mollusks, shrimp, fish, and worms and prey to sperm whales, sea lions, etc...
What is a negative human impact mollusks can have?
hosts for parasites (schistosomiasis) and meningitis
What do annelids and molluscs share in common that indicate a more recent common ancestor/lineage? Name at least 4 things
complete digestive system, trocophore larva, bilateral symmetry, use nephridia, protostomes, coelomates, live on land and in water
Why is it important that cephalopods sufficiently grind their food with their radula before swallowing?
Their esophagus runs through their brain so if the food is not ground up it can cause brain damage
What are the cells called in cephalopods that are responsible for camoflauge?
chromatophores
Where are zebra mussels and giant snails native to? Why are they considered invasive?
Zebra mussels- Caspian sea (Eurasia)
Giant snails- Africa
Outcompete native species
How are pearls formed?
A piece of sediment is blown inside a bivalve, the mantle secretes the same compound as the inside of the shell around the piece of sediment over and over again in layers until a pearl is formed around 5 years later
Describe the circulatory system of cephalopods
closed, heart pumps hemolymph through vessels into the hemocoel where oxygen and CO2 diffuse into the surrounding tissues and organs.