He said the survivors “were clinging to the sinking boat and screaming”.
Betancort added most of the migrants appeared to be between the ages of 25 and 35.
Five bodies, including one of an eight-year-old girl, were recovered on Sunday, Anibal Carrillo, Marine Rescue Service director, told the Associated Press news agency.
Fourteen more were found when rescue operations resumed on Monday.
Thousands of people attempt the treacherous journey from Africa to Spain or the Canary Islands each year, in search of a better life.
Many are caught, but hundreds also die.