A two-headed salmon can lead students to the study of science

Kitsap Sun reporter Marietta Nelson has an affinity for tracking down two-headed salmon.

Two-headed salmon at Woodlands Elementary
Two-headed salmon at Woodlands Elementary

Seven years ago, when she was a relatively new reporter for the Kitsap Sun, she received a call from Ridgetop Junior High science teacher Terry Donison about a two-headed salmon in the classroom aquarium.

She was able to tell the story about Sam and Ella, as the fish was called, in a way that caught the attention of media outlets across the country.

Marietta was gone from Kitsap County for several years as she followed her husband’s Navy career. Now she’s back, covering education, and guess what? Another two-headed salmon has come her way — and she’s all over this new development at Woodlands Elementary.

Read her story in Friday’s Kitsap Sun, which includes a video, and check out her blog, in which she explains how both of these salmon stories came to her attention.

“Sam and Ella” — say it fast — was a name so creative that I recalled it immediately when I learned that Marietta had tracked down another of these fish.

People have always been fascinated with two-headed animals. Peruse the extensive entry in Wikipedia. I think this latest two-headed salmon provides a great chance for the students to discuss embryonic development.

What causes a two-headed fish to be hatched? As in conjoined human twins, two separate embryonic disks become connected early in development and continue to grow together. Perhaps the salmon egg was shocked by bumping the tray, changing temperature or exposing the organisms to chemicals.

But if it’s anything other than a random event, you’ve got to wonder why more fish raised under the same conditions in salmon hatcheries and classrooms do not show up with two heads.

In the Noosa River in Australia, 90 percent of the larvae from fish in the river were found to have two heads. None survived very long. Exposure to pesticides that washed into the river are suspected. The Sunshine Coast Daily covered the story.

If the latest two-headed salmon can survive through this week’s spring break, creative minds will be called on to come up with a name that describes two individuals as well as one.

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