World’s first known ‘Peanut Butter and Jellyfish’

In crazy experiment, sea jellies eat creamy substance, change color, and grow

The world’s first peanut butter and jellyfish; photo courtesy of Dallas Zoo

In an experiment that began partly as attempt to find an economical and sustainable food source for captive gelatinous invertebrates, but mostly just to see if it could be done, scientists have created the first-known “Peanut Butter and Jellyfish.”
In doing so, P. Zelda Montoya and Barrett L. Christie of the Dallas Zoo also proved that scientists are not all left-brain thinkers; they can be highly imaginative and witty.
The experiment entailed feeding tiny aquarium moon jellies protein-rich peanut butter (no preservatives or food starch), and not only did the jellies gobble up to creamy substance, they changed color and experienced noticeable growth.

Moon jelly at left, shortly after feeding, compared to a more pristine-looking jelly at right; photo courtesy of Dallas Zoo

In the January edition of “Drum and Croaker, A Highly Irregular Journal for the Public Aquarist,” the scientists stated that the widespread use of fish- or shrimp-based protein sources in aquaculture represents an unsustainable practice.
“That having been said,” the authors wrote, “we would love to claim we conducted this trial with noble purpose, but the truth is that we just wanted to make peanut butter and jellyfish simply to see if it could be done.

Science thumbnails showing the jellies at various stages of peanutbutterification; photo courtesy of Dallas Zoo

“Whether or not it should be done is a question no doubt to be debated by philosophers for the ages (or at least by some aquarists over beers). We herein report on what we believe to be the first known unholy amalgamation of America’s favorite lunchtime treat and live cnidarians.”
Most surprising of all during the experiment was that the moon jellies actually ate the peanut butter.
As a result, “mean size increased to 4.17±1.06mm (n=19) after eight days of peanutbutterification. By day 31 the jellies had attained a mean size of 17.17±7.44mm (n=12).”
Translation: there was normal or slightly above-normal growth during the experiment, thanks to the fat-rich goodness in peanut butter.
Another surprise besides noticeable growth was the change in appearance shortly after the jellies began to eat (see top image and jelly at left in second image).
“Throughout this period it was noted that jellies that had recently fed displayed a distinct brownish hue owing to their high degree of peanutbutterocity.”
To borrow from a report in Deep Sea News, “They became little peanut butter jelly cups.”
It seems as though peanut-based protein holds promise, but more extensive studies will be needed to determine to what extent it can be used.
As for the Dallas Zoo study, the authors state: “The success of our trial group of Aurelia on this experimental diet was surprising, and we hope this ridiculous experiment illustrates that unconventional approaches in husbandry are at the very least, worth trying once.”