Download - Phylum Porifera
Phylum Porifera
Sponges
Porifera
• Sponges– Living on Earth for at least 540
million years– Most sponges live in the ocean
• Arctic to the tropics • shallow water to depths of
several hundred meters– They are dry sponges were use
for • Bathing• Cleaning
Porifera
• What is a Sponge?1. Sponges are placed in the phylum Porifera (poh-
RIF-ur-uh) which means “pore-bearers.”• Sponges have tiny openings, or pores, all over their bodies
2. Sponges are sessile, meaning that they live their entire adult life
3. They have irregular symmetry
Porifera
• Why are sponges considered animals?– Sponges are multicellular, heterotrophic, have no
cell walls and contain only a few specialized cells.
Water flow
Porifera: Structure
• Specialized cells of sponges:1. Collar cells or choanocytes – Use flagella to
move a study current of water through the sponge.
2. Osculum – A large hole at the top of the sponge3. Spicule – spike-shaped structure made of
chalklike calcium carbonate or glasslike silica4. Amoebocyte – move around within the walls of
the sponge and carry food to other cells
Porifera: Digestion
• Sponges are filter feeders – take microscopic food particles from the water. – As water moves through the sponge,
food is trapped and engulfed by collar cells (choanocytes) that line the body cavity
– Then, food gets passed to amebocytes who take the food to the rest of the cells in the body
Porifera
• How do they breathe?– Sponges rely on the movement of water through
their bodies to carry out body functions:• Respiration – oxygen obtained from the water• Excretion – removal of wastes into the water
Porifera
• How do they reproduce?– Reproduction can be sexually or asexually.– Adults produce gemmules which can withstand harsh
conditions and grow into an adult sponge– Reproduce asexually by regeneration – tear of a piece
of sponge and a complete new sponge will appear.
Porifera
• How important are sponges to the environment?– Many sponges are large and have irregular shapes
and provide habitats– Commensalism and partnerships
• EX: bacteria provide food and oxygen to the sponge while the sponge provides protected area.
Porifera
• Types of Sponges1. Calcareous sponges
Found in shallow waters around the world Spikes made of calcium carbonate (lime)
Porifera
• Types of Sponges2. Glass sponges• Skeleton consists of crystalline silicon dioxide• Generally found in deep, tropical waters
Porifera
• Types of Sponges3. Demospongiae (Bath sponges)• Skeleton is elastic (spongin) fibers• Found in the Caribbean
Encrusting Sponge
Phylum Ctenophora
Comb Jelly
Ctenophora
• Ctenophores (Greek for “comb-bearers”) have eight “comb rows” of fused cilia arranged along the sides of the animal (red rows)– The cilia beat and propel the animal through the
water
Ctenophora
• Ctenophora are commonly known as comb jellies and are voracious predators– 50 species– Most species are planktonic carnivores and
transparent which feed on zooplankton– Light-scattering cilia and bioluminescence– Lack stinging cells but capture prey by sticky cells
called colloblasts– Favorite food of sea turtles
Ctenophora
• Reproduction– Most are hermaphroditic• Release egg and sperm in water, where sperm must
find the egg to fertilize it• Fertilized eggs develop through larval stage that
hatches into an adult; no medusa stage
Sea gooseberry
Phylum Cnidarians
Hydras, jellyfishes, sea anemones and corals
Cnidarians
• What is a cnidarian (ny-DAYR-ee-n)?1. 10,000 species2. Soft-bodied, carnivorous animals3. Stinging tentacles arranged in circles around
their mouths4. Simplest animals to have radial symmetry and
specialized tissues.
Cnidarians
• Specialized cells of cnidarians1. Cnidocytes – stinging cells that are located along
their tentacles2. Nematocyst – poison-filled, stinging structure
that contains a tightly coiled dart.
Cnidarians
• Form and Function in Cnidarians– Simple organisms and only a few cells
thick– Responses to the environment are carried
out by specialized cells and tissues.
• Life cycle that includes two different-looking stages:1. Polyp stage2. Medusa stage
Cnidarians
• Polyp stage– Cylindrical body with armlike tentacles. – Mouth points upward– Polyps are usually sessile
Cnidarians
• Medusa Stage– Motile– Bell-shaped body– Mouth on the botton
Cnidarians
• How do Cnidarians feed?– After paralyzing its prey, cnidarian pulls the prey
through its mouth into its gastrovascular cacity