montereybayaquarium:

Try as she might, MacKenzie Bubel just couldn’t satisfy the baby comb jellies.

The aquarist was attempting to spawn a species called Mnemiopsis leidyi—a ghostly-looking little creature native to the Gulf of Mexico—in the Aquarium’s Jelly Lab. She tinkered with variables like water temperature, salinity and light exposure.

“We did some wacky stuff to get the conditions perfect,” she says, “but they weren’t doing as well as we’d hoped.”

Combing through the science, Senior Aquarist Tommy Knowles first began culturing ctenophores—or “comb bearers”—in 2012. His early attempts were mostly unsuccessful, but they provided a foundation for his team to build on.

Since the mid-90s, the Aquarium’s jelly team has learned how to raise nearly two-dozen species of cnidarian jellyfish—the “classic” jellies we often think of, like sea nettles and moon jellies. Comb jellies, in the phylum Ctenophora, represented a very different challenge to culture.

Figuring out how to grow jellies in-house is a big deal in the scientific world. Not only does it allow aquariums to display these animals for public education without impacting wild populations, it opens the door for labs and researchers to study these elusive, fragile and seasonal animals in greater detail. 

“We don’t know what all their ecological roles are in the wild because comb jellies are so under-studied,” Senior Aquarist Wyatt Patry says.

In wild studies, scientists can only observe “snapshots” of comb jelly life. But in a lab, they can study the animals through their whole life cycle. This start-to-finish overview of ctenophore development can help researchers better understand comb jelly behavior in places like the Black Sea, where invasive Mnemiopsis have decimated fish populations.

And beyond the ecological benefits of understanding how comb jellies make more of themselves, learning about what makes a comb jelly may help improve our picture of how life on earth began.

“Comb jellies are getting much more attention these days because of work in the past 10 years tracing the ancient ancestor to all living things,” says George Matsumoto, senior research and education specialist for MBARI,  “We don’t have a good idea of what this ancestor looked like, but the first group of animals diverging from the tree of life looks like the ctenophores.”

For these scientific reasons and to satisfy their own curiosities, MacKenzie and the jelly team continued to toil away behind the scenes on the combination to unlock the comb jelly code. 

Then, like a pulsating row of cilia, a chance encounter at sea sent the dominos of ctenophore culture falling, one after the other…

Stay tuned for Part 2 and the thrilling conclusion!

Can’t handle the suspense? Click here to watch MacKenzie and co. crack the code of comb jelly culture.