Measuring The Flow Rates of Sponges In a Reef Ecosystem

                The method I use of measuring how fast a sponge circulates.

Sponges are animals in the phylum Porifera, which means they have pores that they use to filter the water around them. These pores are tiny holes in the wall of the sponge, lined with many collar cells. Collar cells have flagella that they beat to create a current of water that passes through the entire sponge. Nutrients and particles are then taken from the water and used. All filtered water is then expelled through the osculum at the top of the sponge. The amount of water that a sponge circulates can be measured by injecting fluorescine dye into the water surrounding the base, and then counting how many seconds it takes for the dye to exit the osculum and travel to the end of a tube 10 centimeters long. I am using this process of measurement in my research project. I’m answering the question “Do sponges of the same species circulate water at the same speed at different parts of a reef ecosystem?” My hypothesis is that sponges found in shallower water circulate faster than those that are found in deeper water. My reasoning behind this hypothesis is that several other filter-feeding animals, which cause competition for particles suspended in water, surround sponges living in the shallow mangrove area. Sponges that are found in deep water are surrounded by much more water, and compete far less for resources.

Tim