The man was being treated for injuries to his left leg at Rand Memorial Hospital, said Dr. Jerold Forbes. He would not say whether the injuries were life threatening, adding only that the man's leg was not severed.
Forbes said the injured man probably would be airlifted to Florida for further treatment.
The hospital did not release the name of the couple involved.
The man was taken later Thursday by airplane to Jackson Memorial Hospital in Miami.
Carlos Cruz, an administrator at Jackson, said the 43-year-old man was in stable condition and had no life threatening injuries, the Miami Herald reported for Friday's editions.
On Aug. 4, another American, Krishna Thompson was attacked during a swim in the waters off the city of Freeport on the south coast of Grand Bahama, where he and his wife were celebrating their 10th wedding anniversary.
The 36-year-old Wall Street banker from Central Islip, New York had to have his leg amputated at the knee.
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