Fishing for parasites at your local seafood market

 

Tested Studies in Laboratory Teaching, 2018, Volume 39

Jill E. Callahan & Kathy A. Nolan

Abstract

In this workshop, we will search for helminth worm parasites in whole, un-gutted, freshly-caught fish obtained from a local seafood market. As a hands-on wet lab activity, students will use an inquiry-based approach to examine fish for the presence of helminth parasites and to assess parasite robustness against various treatments. Such treatments may include varying the temperature by freezing or heating, or altering the pH by adding vinegar or a "citrus marinade". The fish are then dissected, and the organs are soaked in a "sea water" saline solution. When viewed under a dissecting microscope we have often observed parasitic worms swim out of the organs. The students can attempt to key out the worms, quantify, and assess selected treatment efficacy. In addition to learning a bit about the prevalence of parasites and their life cycles, they learn the importance of cooking food, or flash-freezing (as is done with sushi in NYC) in protecting oneself against ingesting parasites.

Keywords:  parasites, Inquiry-based learning, helminth worms, fish dissection

University of Wisconsin, Madison (2017)