Invertebrate Presentation By: Liam Gomez and Dom 

General Description Second largest phylum Largest marine phylum 85,000 different species Highly diverse

Symmetry Bilateral Symmetry – Meaning the two sides are related Both sides when split in two are mirror images of each other Symmetry

Feeding herbivores, carnivores, scavengers, deposit  feeders, filter feeders or parasites. Digestive system has two openings 

Circulation Mollusks have an open circulatory system. Blood flow is not restricted to blood vessels and flows freely throughout the body

The Mollusca excretory process involves the organ of the kidney The Mollusca excretory process involves the organ of the kidney. This organ filters waste from the organism from the blood. Most of the species within the phylum also have an organ called the nephridium, which help maintain a balance of fluids within the body Excretion 

Response  Complexity of nervous system varies greatly; extremely simple in clams, but complex in some octopi

Movement  Varies greatly by group. Some never move as adults, while others are very fast swimmers

Reproduction  Sexual; many aquatic species have free-swimming trochophore larval stage

Gills inside Mantle cavity Respiration  Gills inside Mantle cavity 

Names of classes and examples of each molluska GASTROPODA (single shelled  cowries, cones etc) BIVALVIA ( two shelled like clams, mussels etc) APLACOPHORA (solenogasters) MONOPLACOPHORA (segmented limpets) POLYPLACOPHORA ( or Amphineura as it was earlier called- Chitons) SCAPHOPODA (tusk shells) CEPHALOPODA (nautilus, squids, Cuttelfish, octopus etc)