What's a substitute for pastis?
Yes.  In recipes like bouillabaisse, Pernod, Ouzo, Sambuca, or Ricard would all work as substitutes.  Basically, almost any anise-flavored liqueur will work, although you might steer clear of high-alchohol ones like Raki.

If your local liquor selection is really poor, then maybe either skip it entirely, or add 1/4 tsp ground anise seed to the recipe and some dry white vermouth.