Lab 7 KINGDOM ANIMALIA: PORIFERA, CNIDARIA

Heterotroph

A living thing that must eat other organisms for its energy and food. (A consumer)

Asymmetrical

Having no body symmetry or regular shape. (Like most sponges)

Radial Symmetry

A body plan where similar parts are arranged around a central point, like spokes on a wheel. (Like jellyfish)

Sessile

An animal that stays attached to one place and does not move around.

Filter Feeding

The method of eating by straining food particles out of the water. (Used by sponges)

Endoderm

The inner layer of cells in an animal embryo that becomes the digestive tract.

Ectoderm

The outer layer of cells in an animal embryo that becomes the skin and nervous system.

Spicules

The tiny, needle-like structures made of silica or calcium carbonate that act as the sponge's skeleton.

Choanocyte

The sponge's special "collar cell" with a flagellum (tail) that beats to create water current and capture food.

Amoebocyte

A mobile cell inside the sponge that moves around to carry food.

Osculum

The large opening at the top of the sponge where water that has been filtered flows out.

Spongocoel

The large, central cavity or open space inside the body of a simple sponge

Spongin

A soft, flexible protein fiber that makes up the skeleton of some sponges (like a natural bath sponge).

Mesenchyme / Mesohyl

The gelatin-like layer in a sponge's body that holds all the different cells and spicules.

Ostia

The tiny, small pores (holes) on the side of a sponge where water flows in.

Gemmules

A hard, protected ball of cells that some freshwater sponges make to survive harsh conditions (like a "survival pod").

Epithelial Layer

The outer layer of cells that forms the skin and covers the body of an animal (or lines an inner surface).

Cnidocytes

The stinging cell

Nematocysts

The actual tiny, coiled harpoon inside that cell that fires out.

Gastrovascular cavity

The central stomach-like cavity in cnidarians where food is digested; it has only one opening (mouth/anus).

Tentacles

The whip-like or arm-like parts around the mouth used to capture food and move it into the mouth.

Polyps

The sessile body form of a cnidarian (like a sea anemone or coral); a tube shape with the mouth facing up.

Medusae

The motile (free-swimming) body form of a cnidarian (like a jellyfish); a bell shape with the mouth facing down.

Mesoglea

The thick, jelly-like layer between the two cell layers in a cnidarian (the "jelly" part of a jellyfish).

Basal disk

The flat, sticky bottom part of a polyp (like a sea anemone) that attaches it firmly to a surface.