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Howard Hall films male marbled rays congregating around a single female. Howard Hall films male marbled rays congregating around a single female.
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Courtship of the Marbled Rays
by Peter Tyson
October 13, 1998

The very moment the breakfast bell clanged this morning, Michele Hall and Mark Conlin returned from a scouting dive at Manuelita. As the panga pulled alongside the Undersea Hunter, Conlin called up to Howard Hall on the deck, "It's happening right now, we gotta go right now."

Hall didn't need any convincing. He stepped inside, told those of us preparing to settle down to a leisurely repast to grab a bite and suit up. Three pieces of French toast went down my gullet as fast as greased lightning, and minutes later I found myself bending my knees for balance as we made a beeline for the roughened channel between Manuelita and Cocos.

"I think this will be a three-roll day," Bob Cranston had said optimistically back on the Undersea Hunter. In fact, it would be more than twice that.

We got the tip last night from the captain of the Okeanos, another dive boat whose scuba clients sampled Manuelita yesterday afternoon. Marbled stingrays were massing along the southern tip of the island, he said, dozens and dozens of males going after a single female in heat. Michele Hall told me the film crew had waited since January to film this spectacular courtship ritual.

Closeup of eye and spiracle of a marbled stingray. Closeup of eye and spiracle of a marbled stingray.
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"That was the fastest IMAX yet," Conlin said of our turnaround time. From the moment Hall had interrupted breakfast to the moment Lance Milbrand plunged over the side to deliver the IMAX camera below, no more than 20 minutes had elapsed. Things continued to move quickly after that. It can take an hour and a half or more to shoot a single three-minute roll of film, but Hall was calling for a reload less than 10 minutes after we dispatched Milbrand with the PIG (see The PIG and the Process). By 10 o'clock, Hall had shot all four rolls we had on board the panga, and gave the order to return to the mother ship for more.

That was my cue. Within a minute, I was over the side, finning toward the bottom with Milbrand. We had waited three hours for this, watching squalls sweep down off Cocos and into our faces, and listening to our resident Merry Prankster, Billy Holdson, recite lines from his favorite movies and otherwise keep us entertained.

As we neared the bottom at a depth of 75 feet, the first marbled rays began coming at us. When they realized we weren't rays, much less female ones, they lost interest and swerved off to find the source of the pheremone—or whatever it was that drew them to the lone female like G.I.'s to a visiting starlet. We followed their lead, and soon arrived at the center of the action. It was the underside of a massive boulder lying on edge like a submarine Tower of Pisa, where a pancake heap of rays lay stacked.

I settled down on another boulder not ten feet away. Marbled rays are named for the pattern on their dorsal surface, which in these rays ranged in color from brownish to ashen gray. As round as flying saucers, they averaged about three-and-a-half feet in diameter. Their eyes, so thoroughly camouflaged in their mottled heads that at first it took me a second to locate them, had a bluish cast and were very hard to read. Somehow I couldn't see into them, even though they were wide open.

A lone male ray was a rare sight during the courtship ritual. A lone male ray was a rare sight during the courtship ritual.
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Most arresting, however, was their graceful glide. The way their pectorals described perfect S-curves as they swam reminded me of that famous shot of Marilyn Monroe with her white dress rippling above an air grate. I was mesmerized by their fluid movement. So mesmerized, in fact, that I slipped into that wonderful mental space—usually brought on for me only by concentrated writing—where I feel like I've stepped for a moment out of the flow of time.

Every time I pulled my eyes away from the slow-motion frenzy taking place around the hidden female, I'd see male rays above, around, and beneath me. Again and again I found myself so captivated by a ray sliding past me on one side that I'd fail to notice, until I felt a swish, that another was brushing past me on the other side. The experience was never startling, only delightful. They were so pacific it seemed impossible that their barbs could inflict severe pain.

Without warning, the space under the boulder where the female lay began to boil. Sand and sediment filled the water column, obscuring the view. What was going on? Had one of the males gotten lucky? Or was the female feeling trapped? Neither I nor Michele Hall, who was busy shooting photographs next to me, could see a thing, and for several moments we just waited. Suddenly, a huge ray swam out of the cloud—straight for me. It was the female, and she was easily twice the size of the male clinging to her back.

She wasn't moving fast, and I had time to ease back to give her room. At first I thought the male had scored, but the female soon shucked him off. With a swarm of newly hopeful suitors hovering over her, she settled down on the very spot I'd just vacated. Her spiracle, the silver-dollar-sized gill opening just behind her eye, puffed out particles of sand, which drifted down to rest onto her mottled gray back. I noticed she had lost her barb. To what, a shark?

The water at Manuelita was thick with marbled rays. The water at Manuelita was thick with marbled rays.
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I could have stayed down there for hours, but Hall had requested we remain for only 20 minutes. Michele and I stretched it to 25, then reluctantly headed for the surface.

By two this afternoon, we had shot seven rolls. Hall, Cranston, and Thurlow had been down a total of five hours and 20 minutes. By the time we'd all regrouped for a 3 p.m. lunch—when the filming's good, you don't stop for anything, even the epicurean miracles of Eliu and Alvaro—everyone was charged up. A lively debate ensued about which sequences would now have to come out of the film because of this new addition. Even though that unenviable task was his, no one was more satisfied than Howard, who lives to capture such fascinating animal behavior on film.

"I love the way she'd lose the males," he said, his eyes alive with amusement. "She'd be swimming along with them in hot pursuit, then suddenly double back straight into the pack, scattering the males." He chuckled. "Then they'd stop, looking all confused."

The courtship of the marbled rays is just the kind of wondrous event that occurs as regular as rain at Cocos—and promises to make "Island of the Sharks" a memorable film. For me, it was particularly thrilling to realize that, beginning next spring in IMAX theaters, millions of people will get the chance I had this morning to rub noses with such exquisite creatures.

Peter Tyson is Online Producer of NOVA.

Hammerheads or Bust (Sept. 23)
Get Used To It (Sept. 25)
Nature Reigns at Cocos (Sept. 27)
The PIG and the Process (Sept. 29)
Hammerheads Sighted (Oct. 1)
Assault on Cocos (Oct. 3)
The Director's Cut (Oct. 5)
Swimming with Whitetip Reef Sharks (Oct. 7)
The Magnificent Seven (Oct. 9)
The Search for Lake Cocos (Oct. 11)
Courtship of the Marbled Rays (Oct. 13)
Of Booby and Beebe (Oct. 15)
Taken by Surprise (Oct. 17)
"This is Cocos, This is Cool" (Oct. 19)

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