Watson with zebra sharkWhat do you think of when you hear the word “studbook”? Thoroughbred horses? Pedigreed dogs? How about sharks?

Lise Watson, Wild Reef collection manager, compiled and maintains the studbook for the Association of Zoos and Aquariums’ Species Survival Plan, or SSP, for zebra sharks. An SSP is a carefully managed breeding program developed for species that are declining in the wild. Zebra sharks are heavily fished throughout most of their range, and their reef habitat is disappearing. The SSP is designed to establish healthy, genetically diverse and sustainable populations at Association of Zoos and Aquariums (AZA) member organizations.

“I’m kind of a matchmaker,” Lise quips—one who keeps a detailed and constantly updated database and works with a geneticist and population biologists to make the best-informed choices for several hundred zebra sharks at more than 30 North American aquariums and zoos.

Lise, who has worked with sharks for 27 years, 18 of them at Shedd, gained her expertise with zebras (Stegostoma fasciatum) when these fish were acquired before the 2003 opening of Wild Reef. By 2004, the sharks were breeding without any encouragement, to date producing a record 87 pups. Except for one still at Shedd, offspring have been distributed among 17 other AZA facilities.

But early on, Lise worked with a geneticist to make sure that none of Shedd’s adult zebras were related and to determine the fathers of the pups. That made her think that there should be an SSP—and a studbook—for the species.

zebra shark pup“We were already managing the animals that we had,” Lise says, “and because we had such breeding success and were sharing offspring with other aquariums, we thought it would benefit us to know more about how to manage these animals and be able to provide information to our colleagues on how to breed and rear them.”

In 2009, Lise took AZA’s population management course, and in 2010, she produced the studbook.

“The studbook is a listing of all of the zebra sharks that have ever been kept at AZA organizations, so it’s a historical record as well as a current directory,” she explains. “It also contains as much information as an aquarium or zoo was able to give me on each animal’s size, body weight, length and medical history. It was like putting together a jigsaw puzzle,” she says.

It took her a year to track down and log in all the data—on top of her regular duties caring for all the sharks and managing Wild Reef.

But once compiled, she put it to work. Lise provided all the data to population biologists at Lincoln Park Zoo, who ran the information through a program to sort the animals genetically into six categories of “mean kinship”—or how closely an individual is related to every other shark in the North American zoological population.

“The mean kinship assigns shark pairings a number from 1 to 6 that tells me if animals are a good match or shouldn’t be matched at all. The 1s are best, but 3s are okay. A rating of 6 means no way.”

Using this information, Lise can recommend the best pairings for breeding. “And if an institution wants to move a shark from one place to another to encourage breeding, I help them put the right animals together.”

At Shedd, zebra sharks Seymour, Eli and Vera are in the SSP. Cleo, who produced 86 of the 87 pups born at Shedd, and Andre, who fathered most of them, were retired from the breeding program because “their offspring are at AZA institutions throughout North America, so their genes are out there,” says Lise. Their one offspring still at Shedd, ST10 (aka Bubbles), is also exempt.

But that early success helped launch a wider zebra shark breeding program, and raising all those pups gave Lise unique experience. Now she’s applying her knowledge to a new endeavor. Lise and her European counterpart in zebra shark studbook keeping at a Netherlands zoo, are writing a chapter on breeding and rearing zebra sharks for the second edition of Elasmobranch Husbandry Manual (elasmobranchs are sharks and their relatives).

While zoos have kept studbooks on terrestrial animals such as tigers and rhinos for decades, population management for fishes is relatively new. Lise is one of eight AZA studbook keepers for fishes, including another collection manager at Shedd who oversees freshwater rays. Lise says, “Aquariums want to make the most of their breeding programs and make sure that those animals’ genetics are being maintained. If we can maintain healthy self-sustaining populations in aquariums and zoos, we are also helping populations in the wild.”

Karen Furnweger, web editor