Mollusk Anatomy
Explain 3 parts of the cephalopod anatomy that cause it to be the most active mollusk class.
Siphon: repels the cephalopod backwards at a quick speed
Arms and tentacles: Allows it to grab its moving prey
Developed eyes: allows them to spot, and catch prey, as well as evade predators.
How do larval trochophores move through the water?
By using their cilia
What differentiates tenticles and arms in squid? Do octopus and squid have tenticles or arms?
Tenticles only have suckers at the bottom, whereas arms have suckers going all down them. Therefore, octopus have 8 arms, while squid have have 8 arms AND two tenticles.
Where would the gills of a clam be found?
In the mantle ; the bed that surrounds the visceral mass
What is direct development? Which class of mollusks exhibits it?
When an organisms offpsring looks like a miniature version of the adult ; Class Cephalopoda
What is the least active class of mollusks? Which organism can be the excpetion to this? (HINT: a very silly and unique movement)
Class Bivalvia ; they are sessile and filter feeders. Scallops can "dance" and do upward motions by rapidly clapping their shells together.
When you try to open the shell of a mussel, what part of its body is making it difficult to crack open?
The adductor muscles that hold the two shells together
What is external fertilization? Which organisms exhibit it?
When sperm reaches the egg outside of the body (no penetration) ; non-octopus cephalopods, and bivalves
Break down each class word, and explain why the class has this name (Bivalvia, Gastropoda, Cephalopoda)
Bivalvia(Two-valves): These organisms have two shells, or valves, connected by a hinge
Gastropoda(Stomach-foot): The stomach, or gastrovascualr system, is close to the foot
Cephalapoda (Head-foot): The head of the animal is directly connected to its feet
Explain a unique visual display of aquatic gastropods, and why it exists.
Sea slugs often have bright colors. The colors warn predators that it is a stinging animal, whcih it can obtain from cnidrians.
When a gastropod undergoes coiling, what is the visual result?
A spiral in the shell caused by winding
Invertibrates tend to be more vulnerable to predators due to lack of an internal skeleton. Explain a feature from each class that allows it to defend itself from predators.
Cephalopods: Ink released from siphon to confuse and distract predators, chromatophores allow it to hide by effective camouflage
Gastropods: Stinging cells in sea slugs obtained from close contact with cnidarians, as well as snail shells that protect the snail
Bivalves: thick calcium carbonate shells that are difficult to bite through
The nephridia, which are the paired valves taht release waste
What are 4 key features of the larval veliger stage?
1. Shell Development
2. Foot development
3. Ciliated velum
4. Torsion and coiling
What breakfast food is the same shape of the octopus brain?
A donut!