Phylum Mollusca. Chapter 13: Phylum Mollusca pp. 329-334. Biology fun facts of the day:. Experts claim that about 1,000 oysters must be opened in order to find one usable pearl!. Biology fun facts of the day:.
Chapter 13: Phylum Mollusca
Experts claim that about 1,000 oysters must be opened in order to find one usable pearl!
The common garden snail, Helix aspersa, can travel about 2 feet in 3 minutes. At that rate, it would travel 1 mile in 5.5 days.
(Now you know where the term ‘snail mail’ comes from!)
When we hold a large seashell up to our ear, you can hear what sounds like waves because the shell echoes all the sounds around you.
If you could listen to a shell in a completely soundproof room, you would hear nothing at all!
Many land snails can lift 10 times their own weight up a vertical surface. (If you were this strong, and you weighed 30 kg (about 70 lb), you could carry 300 kg (almost 700 pounds!!!) straight up a wall!
Molluscs represent the second largest animal phylum, following the arthropods
= Old Phylum (500 million years, approx.)
80,000 – 100,000 existing species (estimate)
Most species are free-living
Inhabit a variety of marine, aquatic & terrestrial habitats
Important ecological roles with regards to nutrient recycling; bivalves clean and recycle sediments
Empty shells provide habitat for other invertebrates
likely share a common ancestor
Molluscs all share similar developmental patterns and a common body plan:
Diagrams of snail, clam, and squid p. 300
1) Class Bivalvia
Example members: clams, oysters, scallops
2) Class Gastropoda
Example members: snails, slugs, nudibranchs
3) Class Cephalopoda
Example members: octopus, squid, nautilus, cuttlefish
Molluscs vary a lot clam = representative mollusk
Slow, slick, sliding slug
No protective shield
Create your own mollusc haiku in 5-7-5 format!
Images taken from the following sources: