http://sanctuaries.noaa.gov/education Inspiring ocean literacy and conservation through National Marine Sanctuaries Lesson Plan Filter-Feeding in Reef Sponges FOCUS Food dyes Observe and describe filter-feeding in sponges Hand or electronic fan and explore the ecological role of sponges on Student background information sheet coral reefs Activity C: Sponge Filter-Feeding Activity D: Pumping Rates in the Field FOCUS QUESTIONS Plastic cups or glass beaker • What characterizes a sponge (Poriferan)? Solid object that fits inside glass • What is the feeding method in sponges and how do sponges create the current that AUDIO VISUAL MATERIALS draws water into their bodies? Images of sponges (whole and cross • Why are scientists studying sponges that live sections) on coral reefs? Projector or computer • What role might sponges play in the Video clip of sponge feeding ecology of the coral reef? TEACHING TIME LEARNING OBJECTIVES Activity A: 45-60 minutes Students will: Activity B, C, and D: 30 minutes • learn about the feeding methods of the simplest multi-cellular animals called SEATING ARRANGEMENT sponges. Groups of 4-5 students seated around tables • record their observations of sponges filter- feeding and create a diagram with MAXIMUM NUMBER OF STUDENTS descriptions depicting what they observed. 30 • learn about volume and pumping rates as they relate to sponges on the coral reef. KEY WORDS learn that organisms at the coral reef • Sponges, Phylum Porifera, Cells, Energy interact with one another, sometimes Oxygen, Filter-feeding, Diffusion, Incurrent competing for living space. Pores, Excurrent Pores, Volume, Pumping Rate, Competition, Collar Cells, Sessile, Larvae GRADE LEVEL 4-6 (Life Science) BACKGROUND INFORMATION Activity A—Observing the Sponge Using a MATERIALS Tracer Dye Activity A: Observing the Sponge Using Plants, animals, and other organisms are a Tracer Dye made up of the simplest living units called Paper and poster boards cells. Most cells can only be seen with a Markers microscope. Some very simple animals Activity B: Diffusion Demonstration (protozoans) are made up of only one cell. Shallow clear pan with water Most animals, though, are made multi-cellular or made of many cells. http://sanctuaries.noaa.gov/education Inspiring ocean literacy and conservation through National Marine Sanctuaries Sponges are the simplest of all of the major the room, the perfume naturally spreads out animal groups (called Phyla). Their bodies are from that area of higher concentration to made up of only two different kinds of cells. areas where there is no perfume. This process They do not have nerve cells or sense organs. continues until the concentrations are equal They live underwater, usually in seawater, but throughout the room. there are freshwater sponges, too. Sponge larvae (young) settle on one hard surface and Activity C—Sponge Filter-feeding * then live their lives attached to that surface, *To be read by students as part of step 5 unable to move around to seek food or avoid under the Procedure Section. predators. Remember, sponges live attached to the seafloor. Because they are attached, they Like other animals, sponges need food, are called sessile. In order obtain food, shelter, living space and oxygen to live and sponges pass water through their bodies in a reproduce (have young). process known as filter-feeding. Water is drawn into the sponge through tiny holes The energy needed by sponges and other called incurrent pores. Sponges create the animals is found in the food they eat. Food is current that draws water into the pores using broken down through digestion, freeing up many collar cells, each cell with a whip-like energy that is used for growth and structure called a flagellum and a collar. The reproduction. Animals also need oxygen. collar cells line the channels and chambers Oxygen is a gas that is found in air and in found inside the sponge and by waving their dissolved in water. flagella back and forth in unison, they create a current that draws the water into the Scientists use dyes to trace the pathway of sponge. The collar cells are specialized for substances. A dye makes it easy to follow the carrying out this function of creating a current. pathway of liquids like water. Food coloring is (See diagram/cross section of tissue). a dye. Water exits through larger pores called The video you will be viewing shortly shows a excurrent pores. As it passes through the sponge and a diver. The diver is a scientist channels and chambers inside the sponge, who is carrying out an experiment using a bacteria and tiny particles are taken up from tracer dye on the sponge. After watching the the water as food. The circulating seawater video, you will be asked to diagram and contains oxygen that passes into the sponge describe what you observed. Remember, you cells by simple diffusion. Waste products like make observations by using any one or more carbon dioxide gas and nitrogen and of your five senses. In this case, it will involve ammonia exit with the water leaving the describing what you saw. sponge. Although other animals at the reef are said to filter-feed, the method used by Activity B—Diffusion Demonstration sponges is unique to this simple group of Diffusion takes place when substances animals. In fact, sponges are named because naturally spread from areas of higher of the many pores covering their bodies. They concentration (more of the substance) to belong to the Phylum Porifera and may be areas with lower concentrations (less of the called poriferans. substance). Diffusion does not require any outside source of energy. For example, when Activity D—Pumping Rates in the Field perfume is sprayed into the air on one side of The scientists seen in the video are studying http://sanctuaries.noaa.gov/education Inspiring ocean literacy and conservation through National Marine Sanctuaries the role of sponges on coral reefs in the creating their diagrams. You can use dry Caribbean. They want to know how sponges erase boards, poster boards, plain paper, etc. affect the other animals at the reef, especially and markers, pencils, etc. Photocopy one the corals. In the experiments, scientists use background sheet for each student. tracer dyes and rulers to determine the volume of water flowing through the sponge Activity B—Diffusion Demonstration during a period of time. Volume is a measure Place shallow clear plastic container filled with of the amount of space something takes up or water on a center table. Have food coloring occupies. This measure of the volume of water and fan ready to use. Photocopy one pumped during a certain period of time is background sheet for each student. known as the pumping rate of a sponge. Activity C—Sponge Filter-feeding Scientists are interested in the pumping rates Set up slide presentation showing a variety of of sponges and the total volume of water that living sponges. Also, have slides or photos is pumped through sponges at reefs during a ready of cross sections of sponges showing typical day. The more water that is pumped inner channels and collar cells. You may want through the sponge, the faster the pumping to post or have available the diagrams rate. The water that exits from the sponge created from Activity A. Photocopy one carries waste products like ammonia, nitrogen background sheet for each student and Carbon dioxide gas. This waste nitrogen may be fertilizing seaweeds and helping them Activity D—Pumping Rates in the Field grow. This may important because seaweeds Place beakers or plastic cups on table. Have sometimes compete with corals for space at water and wax pencil or marker available. the coral reef. Use marker board to show math associated with completing the volume problems. Using what is known about sponge pumping Photocopy one background sheet for each rates, scientists can estimate the amount of student water being pumped through sponges on the reef they are studying. This might give them an LEARNING PROCEDURE idea of the how sponges affect water quality Activity A—Observing Filter-Feeding in at the reef. Perhaps, sponges help to clean Sponges using a Tracer Dye particles out of the water, but perhaps they 1. Have students take turns reading also add waste products that help seaweeds. background material in small groups. Review By studying the volume of water being major ideas briefly with class. pumped and the waste products, scientists hope to better understand how corals, 2. Have students watch sponge tracer dye seaweeds and sponges interact with one video. Repeat video. Explain that they will be another on a coral reef. asked to diagram and describe what they observe with their senses. PREPARATION Activity A—Observing the Sponge Using a 3. Working in groups of 3-5, have the students Tracer Dye create a series of diagrams with descriptions Provide video clip for students to view on showing what they observed taking place on projection screen or on their computers. the video. Emphasize that they should work Make sure students have materials to use for together to draw and describe what they saw. http://sanctuaries.noaa.gov/education Inspiring ocean literacy and conservation through National Marine Sanctuaries They should try to draw the sponge and the video. Students observe fan (hand or whatever they saw in as much detail as electric) applied to surface of the water to possible. This can also be done with the entire distribute dye. The fan is a force that moves class, especially if it is small. the dye faster than the process of diffusion. Discuss other ways water can be pumped. 4. Have each student group explain their Mention mechanical pumps like bilge pumps diagram briefly. Discuss the diagrams and that move water.