SPONGESMs. Moore

1/31/13

What is a sponge? Placed in the phylum Porifera (pore bearers)

Live entire adult life attached to a single spot (sessile)

Why are sponges animals? Multicellular Heterotrophic No cell walls Few specialized cells

Form and Function Sponges are asymmetrical = no front/back or left/right

Act as a cylindrical water pump

Choanocytes: specialized cells that use flagella to move a steady current of water through the sponges

Osculum: a large hole at the tope of the sponge where water leaves Water flow is the simple mechanism a sponge uses for feeding,

respiration, circulation, and excretion

Spicule: spike shaped structure made of calcium carbonate or silica Archaeocytes: specialized cells that make up spicules

Spongin is present in soft sponges; network of flexible protein that CAN make up a sponge skeleton

Feeding

Sponges are filter feeders that silt microscopic food particles from water

Digestion takes place intracellular (within the cells).

Choanocytes engulf food particles and digest them; particles are then passed on to archaeocytes to finish off digestive processes

Respiration, Circulation & Excretion

Sponges rely on the movement of water to carry out body functions.

As water moves through sponge cells, O2 can diffuse into cells and CO2 along with wastes can diffuse out of the cells and into the surrounding water.

Response Sponges do not have a nervous system

Some produce toxins that warn predators and make them inedible.

Two nudibranch molluscs, Helgerta sp., feeding on a thinly encrusting red sponge and an algal mat

Reproduction Sexually or Asexually

Sexually: A sponge can produce both sperm and egg on the same

plant, but not at the same time Internal Fertilization: process where sperm fertilizes the

egg inside the sponge body; sperm swims in water to a new sponge, then archaeocytes carry sperm to the egg (attached to walls of sponge)

Asexually: Budding: part of parent breaks off and grows into a new and

identical sponge Gemmules: groups of archaeocytes surrounded by

spicules; can survive freezing temperatures and drought; grow when conditions are favorable

Ecology Ideal habitats for snails,

sea stars, sea cucumbers, and shrimp.

Photosynthetic organisms can live in a sponge and provide it with sufficient O2 and food while the sponge provides the organism a place to live. Spicules can direct sunlight

to organisms living in the sponge when sunlight is low or limited.

Mini Lab Create a booklet showing the body

plan, water flow, and reproduction of a sponge.

Make sure you have the illustration regarding early development (blastula) in your notes from yesterday.

Exit Ticket Making connections: What type of

relationship would a shrimp and sponge share? Who would benefit? Why? What about a star fish and sponge?