It is unlikely that the suspects, accused in a crime that has shocked many in South Africa, will be granted bail, officials have said.
An eighth suspect, a man who was found with the victim, is scheduled to appear in court on May 4, court officials said.
The images of the assault of a 17-year-old girl, believed to be mentally ill, swept across the Internet last week and touched a nerve in South Africa.
The shocking footage shows the girl pleading for her attackers to stop, and it has some activists saying it is an example of the country's problem with rape.
The 17-year-old girl went missing on March 21. Police suspect she was kidnapped and turned into a sex slave. The cellphone video of her gang rape surfaced and went viral among school children in Soweto, the vast township near Johannesburg.
The Daily Sun, a local tabloid, alerted the police about the attack after a concerned mother whose daughter was watching the video handed it over to the paper.
Police embarked on a search for the girl and the people in the video.
Eight suspects have been arrested and charged with kidnapping and rape of the teen. Seven of them, ranging from ages 14 to 20, were seen on the video; the other was a 37-year-old man found with the girl last week.
According to estimates by non governmental agencis in the country, a woman is raped every 26 seconds in South Africa.
More than 60,000 cases of sexual assault were reported in the year to March 2011, down from 70,000 in 2008, police said.
Women's rights activist Lisa Vetten says in the province of Gauteng, where Johannesburg is located, one in every five rapes is a gang rape.
"Rape is a young man's crime. It's a bit of a performance for them, showing off to each other how macho they are. We need to teach our young men that you can be masculine in ways that do not involve violence and degrading women," she said.
The victim's mother has said this was not the first time her daughter has been raped.
She was raped in 2009 and 2010 and authorities have done little to address the issue in the past, the mother said.
"It's 2012 now, and I'm still waiting for DNA results," the mother said.
After the girl was found and as the news of the video emerged, the government placed her in a safe house -- a place where she can attend school and socialize in a secure environment.
"They are coming now because things have turned out this way," the mother said. "They shouldn't pretend as if they have been standing up for me. They never stood up for me."
Click here to watch the video of the Mother of rape victim in video speaks