MOLLUSCA: MOLLUSCA “Rockin’ Earth since the Precambrian” Key Features of Mullusks: Key Features of Mullusks Mollusks are coelomate invertebrates
(they lack a backbone and possess an internal cavity also known as a coelom)
Mollusks are bilateral
(they develop equally on both sides and are not radial)
In most mollusks, the ventral side develops into a locomotory organ, such as the foot, or broad flexible disc.
Most produce a hard exterior shell while some produce an internal shell; however, a few species have no shell such as garden slugs or sea nudibranchs.
Posses a mantle
(A “fleshy fold” that surrounds most of the body and protects the major organs)
All classes of mollusks excluding the bivalvia have a radula
(A tooth like chitinous ribbon used to tear apart food and bore holes in prey)
The nervous system is composed of a relatively undeveloped brain and organized ganglia
(A group of nerve cells forming a nerve center) Features Shared With Related Groups: Features Shared With Related Groups Tissue:
Chordata Bilateral Sym.:
Chordata Body Cavity:
Anthropoda Get Acquainted With Mollusks!: Get Acquainted With Mollusks! Mollusca Conchifera Aculifera Solenogastres Caudofoveata Placophora Tryblidiacea Gastropoda Scaphopoda Bivalvia Cephalopoda Phylum Sub-Phylum Class Kingdom Animalia Two Classification Systems: Gastropoda Scaphopoda Bivalvia Cephalopoda Aplacophora Polyplacophora Monoplacophora 1 2 Fundamental Biology: Fundamental Biology World distribution could rival some extremophiles
-Deepest parts of the ocean under immense pressure at thermal vents to the thin air at 5,000m on the Himalayan Mountains
-Thermal springs at temperatures reaching 104 degrees Fahrenheit, to ice frozen from artic winters
-Different species have adapted to accommodate their motion capabilities: Many of those species which are fixed in location are hermaphrodites, meaning they possess the sex organs of both sexes. Other mobile species are known to fertilize an area in hopes of fertilizing a patch of eggs left by a female.
More Fundamental Biology: More Fundamental Biology Mode of Nutrition:
-All classes of mollusks excluding the bivalvia have a radula - used to scrape algae from hard surfaces or attack and kill prey. Others species entrap prey with projectile mucus, or secrete acid to kill, immobilize, and decompose what they are hunting
-Herbivores (primary consumers) feed off of local plant life, such as algae, weeds, or crops
-Carnivores (secondary consumers) prey on the primary consumers and keep their population at equilibrium, which in turn helps the plant life remain abundant
-Decomposers break down the dead and decaying matter in their habitat
Why Mollusks are Important + Fun Facts: Why Mollusks are Important + Fun Facts Everyone is familiar in someway with at least one member from the amazingly diverse phylum known as Mollusca.
A variety of mollusks, such as clams, scallops, shellfish, and even squid and octopi, provide an appetizing seafood dish.
The shells of mollusks have been used as ornamental jewelry, charms, and even currency.
Of course, pearls make for highly valued earrings and necklaces.
Countless horror movies were produced with inspiration from the unknown tentacled-monsters based on squid and octopi.
Bulinus globosus, an aquatic snail found in northern Zimbabwe, hosts a parasite which causes the disease schistosomiasis, and is a major health problem in many developing countries.
On the other hand, venom produced from some species is being researched for medical use
A species of Octopus has the uncanny ability to imitate other creatures to escape predators
Slide8: Pictures as taken from www.personal.psu.edu/slr934