Oysters are suspension-feeders that filter water, drawing water in over its gills through the beating of cilia. Suspended food (plankton) and particles are trapped in the mucus of the gills and transported to the mouth, where they will be either eaten, digested and expelled as feces or not consumed, combined with mucus and expelled as psuedofeces. Feeding activity is greatest in oysters when water temperatures are above 50°F (~10°C).
The procedure for performing a live filtering experiment is simple and requires only a few pieces of equipment. Viewing this experiment is best accomplished with a stereoscope to get the full effect of the movement and transport of particulate matter by the oyster.
This activity combines a hands-on exploration with an online resource. Teachers can walk through the activity with the entire class or students can work independently. An offline resource is also available for download to a local computer.
- Observe and describe the feeding process of the eastern oyster and identify key anatomical structures and functions involved in the process.
- Observe and describe the difference between food consumption and the production of pseudofeces.
- Oyster knife
- Sturdy gloves
- Artificial saltwater (10-15ppt)
- Computer access
Per Lab Group:
- Live oysters
- Shallow glass or plastic dishes (min 2” depth)
- Carmine Alum Lake
- Small glass cup or beaker
- Glass transfer pipette or eye dropper
- Computer access
- Stereomicroscopes (optional)
- Large magnifying glasses (optional)
- For optimum results, oysters should be held in a saltwater tank for 24 hours prior to the lab.
- Prepare a Carmine Alum Lake suspension for each lab group by placing 0.1 g of carmine alum lake and 5 ml of seawater from the oyster tank into a small cup, beaker, or test tube. Mix until all of the Carmine Alum Lake is suspended.
- Shuck 1 oyster per lab group and 1 oyster for demonstration (for safety purposes it is not advised to have students shuck their own oysters). Use the hinge method to shuck the oyster to ensure that its internal anatomy stays intact. In this method, you will be removing the right valve of the oysters – be sure to leave the oyster attached to its left valve.
- Place oyster (in its left valve) in a dish and submerge the oyster in artificial seawater (none of the oyster or its valve should be exposed above the surface).
- Give each student group their own shucked oyster/dish combination along with prepared suspension.
- As a class or independently, have students access and complete the Particulate Matters Lab.
- Have students discuss or write a conclusion about the fate of the suspension and how the oyster altered it.
- Have students discuss, write or illustrate (draw or video) how the suspension-feeding process impacts the health of the Chesapeake Bay?
Next Generation Science Standards
Performance Expectation HS-LS1-2
- SEP: Developing and Using Model
- Modeling in 9–12 builds on K–8 experiences and progresses to using, synthesizing, and developing models to predict and show relationships among variables between systems and their components in the natural and designed worlds.
- Develop and use a model based on evidence to illustrate the relationships between systems or between components of a system. (HS-LS1-2)
- DCI: LS1.A: Structure and Function
- Multicellular organisms have a hierarchical structural organization, in which any one system is made up of numerous parts and is itself a component of the next level. (HS-LS1-2)
- CC: Systems and System Models
- Models (e.g., physical, mathematical, computer models) can be used to simulate systems and interactions— including energy, matter, and information flows—within and between systems at different scales. (HS-LS1-2)
Performance Expectation HS-LS2-6
- SEP: Engaging in Argument from Evidence
- Engaging in argument from evidence in 9–12 builds on K–8 experiences and progresses to using appropriate and sufficient evidence and scientific reasoning to defend and critique claims and explanations about the natural and designed world(s). Arguments may also come from current scientific or historical episodes in science.
- Evaluate the claims, evidence, and reasoning behind currently accepted explanations or solutions to determine the merits of arguments. (HS-LS2-6)
- DCI: LS2.C: Ecosystem Dynamics, Functioning, and Resilience
- A complex set of interactions within an ecosystem can keep its numbers and types of organisms relatively constant over long periods of time under stable conditions. If a modest biological or physical disturbance to an ecosystem occurs, it may return to its more or less original status (i.e., the ecosystem is resilient), as opposed to becoming a very different ecosystem. Extreme fluctuations in conditions or the size of any population, however, can challenge the functioning of ecosystems in terms of resources and habitat availability. (HS-LS2-6)
- CC: Stability and Change
- Much of science deals with constructing explanations of how things change and how they remain stable. (HS-LS2-6)
Performance Expectation HS-LS4-5
- SEP: Engaging in Argument from Evidence
- Engaging in argument from evidence in 9-12 builds on K-8 experiences and progresses to using appropriate and sufficient evidence and scientific reasoning to defend and critique claims and explanations about the natural and designed world(s).
- Arguments may also come from current or historical episodes in science.
- Evaluate the evidence behind currently accepted explanations or solutions to determine the merits of arguments. (HS-LS4-5)
- DCI: LS4.C: Adaptation
- Changes in the physical environment, whether naturally occurring or human induced, have thus contributed to the expansion of some species, the emergence of new distinct species as populations diverge under different conditions, and the decline–and sometimes the extinction–of some species. (HS-LS4-5)
- CC: Cause and Effect
- Empirical evidence is required to differentiate between cause and correlation and make claims about specific causes and effects. (HS-LS4-5)
Maryland E-Lit Standards
- (2) Human Dependence on Earth Systems and Natural Resources. Environmentally literate students construct and apply understanding of how Earth’s systems and natural resources support human existence.
- (3) Environmental Impact of Human Activity. Environmentally literate students construct and apply understanding of the environmental impact of human activities on Earth’s systems and resources.
They're all related to human activities. These could work depending on the connections you make to humans.
Hinge method of shucking an oyster
Particulate Matters Lab
**Use of images with permission, J. Adam Frederick**