Faisal Naseem was picked by the JP for the opposition coalition's joint ticket.
There was a secret ballot during a Jumhooree Party meeting.
The final candidate list will be announced August 18.
Young men on motorbikes confronted and tried to attack the opposition's presidential candidate.
Nasheed's decision not to run for president shocked, and even divided, the party he leads.
Clerics said it was a 'golden opportunity' for advancing Islamic traditions.
Dr Shaheem previously served as Islamic minister in President Yameen's cabinet.
The MDP maintains its stance that the Elections Commission must be reconstituted.
Religious scholars are opposed to a female vice presidential candidate for the coalition's joint ticket.
India urged "credible restoration of the political process" before September's presidential election.
Amendments to electoral laws were voted through with only 34 out of 85 MPs present.
The Maldivian professor gave no reason for his decision.
The president slammed foreign interference and vowed harsh punishments for Maldivians who insult Islam.
Ibrahim Mohamed Solih has never sought the spotlight or headlines.
The main opposition has five focus areas in its manifesto.
One minister hoped 'honest campaigning' could now begin.
Debate is raging about who should be the main opposition's presidential candidate.