Mote Marine Laboratory

Cartilaginous Compendium

By: Patrick Maggard

For a quarter century, José I. Castro’s The Sharks of North American Waters has been the field guide for researchers and laymen with sharky interests.

In 2009, after years of hard work and with the help of colleagues, recreational fishermen, a famous wildlife illustrator, and a custom-made 8-foot-long plastic cooler he likes to call a “sharkophagus,” Castro, a Mote senior biologist and National Oceanic and Atmospheric Administration scientist, will publish a new shark book.

“Since his original book came out in 1983, 25 years have passed,” said Bob Hueter, director of Mote’s Center for Shark Research. “Some new species have been discovered; some species’ names have been changed. Tremendous amounts of new information have been brought to light by researchers around the world, so he has a lot more information to put into a book than 25 years ago.”

Castro wrote The Sharks of North American Waters because, simply put, there was no reliable field guide for sharks at the time. “People were misidentifying sharks all the time,” he said. “They were using the few available guides, and even trained people were misidentifying sharks. Basically, I started out with the questions: What sharks inhabit North American waters? And what do we really know about them?”

The answer to the second question was: Not much.

In the early 1980s, commercial shark fisheries didn’t exist, so not many scientists were studying sharks. But in the late ’80s and early ’90s, shark fisheries developed, which created a lot of interest in sharks as scientists grew concerned that some species were being overfished. So more people started studying sharks.

Castro’s first book contains exhaustive information on 112 shark species — description (including the number and shape of teeth), geographical range, diet, reproduction and relation to man (is a species commercially and/or recreationally important? Is it dangerous).

The new book started out as a revision of the first. Then people called and asked that he add information. Pulling together so many details on so many species was not an easy task. “It was tough,” Castro said. “Sometimes I couldn’t depend on the literature. In shark biology — not like other sciences where, when you publish something, people check it right away — sometimes what’s published remains there for decades because so few people were working on sharks. There was a lot of misinformation out there.”

Not wanting to rely on faulty literature, Castro was eager to look at specimens, which he pored over, photographed and dissected. “Specimens are critical,” he said. “One time, somebody asked why we need specimens. Without specimens, how do we compare it to other species? How do we verify things? How will the artist draw it?”

Some shark specimens are easy enough to come by. Anybody fishing in a Florida bay or from a bridge can catch a blacktip or nurse shark. But what about something like the cigar shark, which is only 14 to 50 centimeters long and spends its days a couple of thousand feet down in tropical waters?

“Somebody was marlin fishing off Honolulu and got delayed out there and was coming back in the dark,” Castro said. “They saw something luminescent floating at the surface and picked it up with a net. They took it to the Waikiki Aquarium, where Jerry Crow identified it as a cigar shark. He called me that day and asked if I needed it. I never expected to get one. It’s the only fresh one I’ve ever seen.”

The Sharks of North American Waters contains black-and-white drawings of each shark species; for The Sharks of North America, marine-life artist Diane Rome Peebles of St. Petersburg made color illustrations. “I wanted definitive illustrations,” Castro said. “Ninety-five percent are from fresh specimens.”

Most of Castro’s specimens were supplied by other biologists, including a large bignose shark, the story of whose acquisition is a perfect example of scientific teamwork.

“I was traveling back from Georgia, and I got a call from my friend Dean Grubbs (of Florida State University), who was in the Bahamas and said he’d caught the largest bignose shark he’d ever seen,” Castro said. “I said, ‘Put it in a freezer until I can get down there.’ He said, ‘There are no freezers here.’ I said, ‘Go buy one or get some ice.’”

A few hours later, Grubbs called again, saying he’d found a freezer, but he had to fly back to the United States the following morning and would try to put the shark on a boat bound for Fort Lauderdale.

“The following morning, he called and said he’d talked the crew of his plane into putting a 300-pound shark wrapped in a tarp on the plane,” Castro said. “Then I arranged for him to take it to a freezer in Miami, then I took my sharkophagus to pick it up. By the time I got there, it had thawed. But it was a beautiful specimen, and it made a beautiful illustration.” 

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