1. There are about 85,000 known species of mollusks today, including snails, slugs, clams, squids, and octopuses.
2. Three mollusks that look very different from each other are:
a. Giant clam (large and shell-like)
b. Blue-ringed octopus (small and colorful)
c. Sea hare (resembles a blob-like creature)
3. The body plan of most mollusks includes a muscular foot for movement, a visceral mass containing organs, and a mantle that often secretes a shell for protection.
4. The leafy hornmouth avoids being crushed by the crab by utilizing its strong shell and retracting into it when threatened, making it hard for the crab to break through the protective barrier.
5. Another mollusk defense mechanism is ink secretion. Some mollusks, like squids and octopuses, release ink into the water to create a distraction and confuse predators, allowing them to escape.
6. A biomechanical feat of the mollusk foot is its ability to produce adhesive secretions that help the mollusk grip surfaces, crawl, and anchor itself in various environments, showcasing both strength and flexibility in movement.
7. When the sea star catches up to the abalone, the abalone can clamp down on the substrate using its foot, making it challenging for the sea star to dislodge it, and it can also twist its shell to avoid being flipped over.
8. The first cockle avoids the moon snail by sensing the snail's approach through its sensitive foot and using its muscular foot to burrow deeper into the sand, escaping the moon snail's predatory intentions.
9. On its second approach, the moon snail may use a different strategy by secreting an acid that softens the cockle's shell, making it easier for the moon snail to drill through and access the soft tissues inside, ultimately consuming the cockle.
