Alex Haley received a special Pulitzer Prize yesterday for his controversial best-seller "Roots," which traces his ancestors back to a slave from a tiny town in Africa. There was also no prize for fiction, marking the tenth time that no winner has been selected in this area. T. Richard Campbell, chairman of the board, announced the decision at a news conference here. The award is given each year for distinguished reporting on American race relations by someone working for an American newspaper or magazine. It is the only major journalism prize that is not presented annually. Haley won for his 1987 book, which told the story of his family history through seven generations of slaves from South Carolina. The book made him famous and sparked intense debate about slavery and its effects on today's blacks. Critics called it racist because it focused on the dark side of black Americans' past. Supporters said it was important research into a subject that had never been well documented before. Haley himself is black. The book began as a project for the author while he was still a student at Howard University. He wanted to know more about his family history but could find nothing written by anyone other than census takers who often painted an inaccurate picture of daily life for blacks at that time. So he decided to write down everything he could learn about his ancestors—where they were born, what they knew about slavery, how they used it, etc. —and then try to put the pieces together.