Allen Collins studies the diversity of jellyfish to help piece together answers about ocean ecosystems

One thing he’s learned: Don’t pee on a jellyfish sting (use vinegar instead!)

From the deep ocean, where sunlight never reaches, to sunny stretches of shoreline; in the warm waters of the Caribbean to the frigid seas on the Artic, you will find creatures like no other: amorphous, translucent, alien-like beings that predate the dinosaurs. This ancient collection of animals, called cnidarians, sit right near the base of the tree of life, yet they are among the most diverse set of animals on the planet. And that is what Allen Collins loves about them.

Allen Collins switched careers from an economist to a biologist when he took a night course on the history of the Earth and became fascinated with the many questions about how the natural world came to be. Image: courtesy of Allen Collins

Collins is a curator of marine invertebrates at the National Museum of Natural History, and he is on a quest to identify, name, and categorize the rich diversity of cnidarians, namely jellyfish, comb jelly, and deep-sea sponge species found throughout the ocean. “We’ve named about a quarter million species in the ocean, but there’s an estimated one to two million marine species in total,” Collins explains. “That means we’ve only named a quarter to an eighth of the known species.”

This tiny jellyfish, Vallentinia gabriellae, also referred to as the hitch-hiking jellyfish, usually only reaches a size of half an inch. Image: Allen Collins

Collins wants to know them all because, as he explains, “science helps us organize life. When we see [species] that don’t have names, it’s our job to give them names and describe them. I have this idea that each species on the planet is incredibly complex. Each comes with a multifaceted story of how it fits into the environment.” Learning about the diversity of cnidaria solves a major portion of the jigsaw puzzle that is the marine ecosystem, which helps scientists ask and answer new questions about how different species in the ocean depend on each other for survival.

Collins described this quest using a phrase often recited by biologists: “a fly isn’t just a fly.” It is the idea that if you look at a group of flies from a distance, they’ll all look the same. But if you dig a little deeper, you will notice that flies come in a lot of shapes, sizes, and colors. “It’s the same with jellyfish. There are so many different kinds. Some offer very clear benefits to us, and some are harmful,” Collins said.

For example, jellies are one of nature’s carbon sinks—they eat organic carbon and when they die, they literally sink to the ocean floor, bringing that carbon with them. One study found that they capture carbon at roughly the same rate the U.S. emits it. “They’re also really important predators,” Collins said. As carnivores, “they play critical roles in the marine food web.”

The Cassiopea jellyfish, or upside-down-jellyfish, is one of many diverse jellyfish species. Image: Allen Collins

Collins told us that his mind keeps going back to the diversity of jellies, because the surprises never stop. “I love learning about more aspects of their biology. Some jellies have algae growing inside their tissues. Some swim more than others.” And every species’ life cycle is a bit different. “Some skip stages of the development process,” Allen described. “When larvae settle and turn into polyps, some make baby jellyfish off their tops and some off their sides. Some polyps just turn directly into jellyfish and swim away.”

Many cnidarians do, of course, sting, and Collins knows it from first-hand experience. “When you get stung, the stinging capsules that they discharge explode, and they leave some stinging cells stuck on you,” Collins explains. “If you rub the sting or spread a topical ointment on it, you’re just going to spread the cells and it’s going to cause more stinging. Instead, rinse the sting with vinegar. The acid stops the microscopic stinging cells from shooting out toxin.”

But we do not have to fear jellyfish, Allen argues. While some species do sting, “a lot of people have seen jellies swimming in aquaria and are mesmerized. I liken it to watching a fire. You can just stare at them for hours.”

Collins enjoys working with students of all ages to cultivate curiosity. Image: courtesy of Allen Collins

Collins started off with a career as an economist, but when he took a night course on the history of the Earth, he realized there were so many open questions about how the natural world came to be, and he wanted to be part of answering those questions. Collins quit his job and started taking undergraduate biology courses, then he completed his Ph.D. looking at animal fossils. But he found that living animals interested him more; he wanted to take a big picture look at a whole phylum of animals and how they fit together within the larger ecosystem.

“When I first started being a scientist, the thing I felt most proud of—the thing I found most meaningful, was finishing a paper, because I knew I created knowledge that would then be humanity’s knowledge.  It was so cool that I was leaving something for the future. It’s the same sort of satisfaction to interact with young people in my lab, cultivating their curiosity. My favorite definition of science is ‘curiosity acted upon.’ To see people I’ve trained go off and do new things and have success in science or another field, all those experiences are equally important than all the science I’ve ever done. It gets me right at my heart.”

Eye on Science shines a light on our vast and varied body of work by bringing Smithsonian science into sharper focus. Eye on Science tells the stories of the people behind the research, the discoveries they make and their inspiration. We will explore their passions, celebrate their contributions, and look more closely at how questions become solutions that can inform environmental policy, spur technological innovation, and promote community and collaboration across the globe. Eye on Science is also published by si.edu as Meet a Scientist.