Published: May 21, 2019

3 Questions with a Scientist: Baby Sharks

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A shark DNA expert answers three burning questions.

Using DNA analysis, Kevin Feldheim and fellow researchers found that baby tiger sharks are more savage than we thought (baby shark, doo doo d–). They eat birds, though not seabirds like you might guess. Feldheim and team studied feathers that sharks ingested to learn that they’re scooping up familiar songbirds like sparrows and woodpeckers—which get tired during migration and land in the ocean.

What’s the weirdest thing you’ve analyzed in the DNA lab—does shark barf take the prize?

Bird feathers from sharks' stomachs is right up there. This is one of the coolest projects I’ve been a part of that uses DNA to tell a story.

But some other weird or cool things include: testing cans of soup to determine if they contain shark products (which are illegal in Illinois), discovering that a shark fin confiscated from a Chicago business belonged to a whale shark, analyzing baby sharks born in aquaria that were the result of parthenogenesis (reproduction without fertilization or “virgin birth”), and testing pot stickers sold as "shark dumplings." The dumplings, although advertised as shark, contained shrimp.

A man holds a large white, dried shark fin, which appears about two feel tall. The background is of an office that has a few plants and natural history-themed images on the walls.

After DNA testing this confiscated fin and determining it belonged to a whale shark, Feldheim now uses it for educational purposes. It's illegal in Illinois to buy and sell products from the elasmobranch fishes (sharks, skates, and rays). 

Sharks sometimes get a bad rap. What’s something you want people to know about them?

Sharks are vital to a healthy ocean ecosystem. Also, you are more likely to get killed by a lot of things other than shark attacks (as one of my favorite comics illustrates).

All sharks are in trouble. We don’t know the extent of how industrialized fishing has taken a toll, but the vast majority of top predator populations have declined in recent years.

Kevin Feldheim

If you weren’t studying shark DNA, you’d be...

I don't know, I can't imagine doing anything else. Maybe a DJ.

Bonus question: Cutest shark?

Baby zebra shark. I mean, c’mon...how cute are they?!

A black-and-white striped baby shark in an aquarium, with pebbles beneath it and mossy rocks behind it.

A baby zebra shark.

Mark Feguson

Kevin Feldheim uses DNA to study sharks’ genetics and mating habits and manages the Pritzker DNA Lab at the Field Museum. His research contributed to a paper on baby tiger sharks in the journal Ecology. Read more about it in The Atlantic.