Three-Point Linkage with Drosophila
May 14, 2024
In this lab, students observe vinegar eels. These small animals, barely visible without magnification, are found in unpasteurized cider vinegar, where they feed on the bacteria responsible for the conversion of apples to vinegar. Vinegar eels, Turbatrix aceti or Anguillula aceti (Muller, 1783), are examples of roundworms, or nematodes..
Determine stream water quality based on a macroinvertebrate inventory.
If microscopes with scanning lenses are not available, you may use stereomicroscopes (591815) (dissecting scopes). Without the substage lighting and iris diaphragm, though, students will not see as much detail as with a compound scope. Vinegar eels move vigorously and, even with Protoslo®, it may be difficult to keep them in the field of view. Removing some of the liquid under the coverslip helps confine them. Hold Bibulous Paper (634050) or a paper towel at the edge of the coverslip to absorb some of the trapped fluid.
Ensure that students understand and adhere to safe laboratory practices when performing any activity in the classroom or lab. Demonstrate the protocol for correctly using the instruments and materials necessary to complete the activities, and emphasize the importance of proper usage. Use personal protective equipment such as safety glasses or goggles, gloves, and aprons when appropriate. Model proper laboratory safety practices for your students and require them to adhere to all laboratory safety rules.
Vinegar eels are not parasitic or pathogenic. Even so, know and follow your district’s guidelines so that you are prepared should a student ingest a culture. Cultures remaining after the completion of the activities can be flushed down a sink with tap water. The chlorine or chloramine in most treated tap water will kill vinegar eels. If your tap water is not chlorinated, pipet 1 mL of household bleach (sodium hypochlorite solution) or isopropanol (rubbing alcohol) into the culture and wait 15 minutes before flushing down the sink.
Students may work individually or in pairs.
Because of vinegar residue, the droppers used in this exercise should not be reused with cultures other than vinegar eels.
For each vinegar eel culture, set up a workstation with the following:
Optional:
If your students are not familiar with basic characteristics of animals, consider also using two other LabSheets, Introduction to Hydra and Introduction to Planaria.
*Next Generation Science Standards® is a registered trademark of Achieve. Neither Achieve nor the lead states and partners that developed the Next Generation Science Standards were involved in the production of this product, and do not endorse it.
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