Presentation is loading. Please wait.

Presentation is loading. Please wait.

Invertebrate Phylum Mollusca (Mollusks).

Similar presentations

Presentation on theme: "Invertebrate Phylum Mollusca (Mollusks)."— Presentation transcript:

1 Invertebrate Phylum Mollusca (Mollusks)

2 Vocabulary visceral mass = contains internal organs of digestion, excretion, and reproduction mantle = thin membrane that surrounds internal organs

3 Vocabulary Radula = tongue-like structure with teeth used to grate, cut, and scrape Torsion = visceral mass twists 180* in relation to head Siphon = fleshy tubes for movement of water in a mollusk

4 Characteristics true coelm * bilateral symmetry * two body openings
* 3 body parts: head, muscular foot, visceral mass * most have shell secreted by mantle * gills for gas exchange with water * some have a radula for feeding

5 Three Major Classes

6 Gastropoda: "stomach foot"
* single shell - snails, abalone, conch * no shell - nudibrachs, slugs * move by muscular contractions of foot * open circulatory system




10 Bivalvia: shell with "two valves”
* clams, oysters, scallops * strong muscle for pulling shell and burrowing * no head or radula * filter food from water via gills; cilia move food to stomach

11 Cephalopoda: "head-foot”
* octopuses, squid, nautilus * free swimming; predatory; tentacles with suckers * radula and sharp beak * large brain and advanced nervous system * closed circulatory system



Download ppt "Invertebrate Phylum Mollusca (Mollusks)."

Similar presentations

Ads by Google