| A | B |
|---|
| Nerve Net | the network of interconnecting nerve cells in cindarians and other invertebrates |
| Collar Cells | a flagellated, food-trapping cell of sponges |
| Flagella | a long whip like organelle that is usually involved in locomotion |
| Planula | the ciliated larva of cindarians |
| Osculum | a large opening in many sponges |
| Spongin | the resistant fibers of sponges |
| Filter Feeders | a suspension feeder that actively filters food particles |
| Spawning | the release if gametes or eggs into the water |
| Larva | immature stage of an animal that looks different from the adult |
| Polyp | the cylindrical, typically attached stage of cindarians |
| Medusa | the bell-shaped, free swimming stage of cindarians |
| Nematosysts | the stinging structure of cnidarians |
| Coral | a massive deposit of calcium carbonate by colonial stony corals and other organisms |
| Statocysts | a fluid filled cavity provided with senstive hairs and a small free body that is used to orient animals with respect to gravity |
| Radial Symmetry | the regular arrangement of similar body parts around a central axis |
| Bilateral Symmetry | the arrangement of the body parts in such a way that there are only two identical halves |
| Deposit Feeder | an animal that feed on organic matter that settles on the bottom |
| Polychaetes | segmented worms that typically have parapodia |
| Trocophore | a planktonic larva found in polychaetes, some molluscs and other invertebrates |
| Segmentation Flukes | invertebrates that display an elongate body with distint segmentation a s digestive tract that lies in a coelom |
| Umbo | the region around the hinge of a bivalve's shell |
| Mantel | semi-liquid region between the crust and core of earth |
| Radula | the ribbon like band of teeth of molluscs |
| Chitin | a complex derivative of carbohydrates that is the main component of the skeleton of many animals |
| Gastropods | snails, slugs; have a coiled dorsal shell and a ventral creeping foot |
| Nudibranchs | gastropods that lack a shell and have exposed gills |
| Bivalves | clams, mussels; have two shells, filtering gills and a shovel-like foot |
| Cephalopods | octopuses, squids; have a food modified into arms that surround the head |
| Tentacles | a flexible, elongate appendage |
| Byssal Threads | strong fibers secreted by mussels for attachment |
| Siphons | a tube-like extension through which water flows in and out of the mantle cavity in bivalves and cephalopods and in tunicates |
| Pen | the reduced, thin shell of squids |
| Chitons | molluscs that have a shell divided into eight plates |
| Hermaphrodite | an organism that has both male and female gonads |
| Veliger | a planktonic larva in gastropods and bivalves |
| Valves | any of the two shells of bivales and lamp shells |
