Mongoose coection.on('open') never gets called inside my controller.js

My Main server.js code where i start my server and coects to mongoDb Server

if(process.env.MONGOLAB_URI) {
    mongoose.coect(process.env.MONGOLAB_URI);
} else {
    mongoose.coect("mongodb://localhost/itrack");
}

mongoose.coection.on('open', function() {
    // This line is getting printed here
    console.log('Mongoose opened.');
});
// When successfully coected
mongoose.coection.on('coected', function () {  
    console.log('Worker ' + process.pid + ' is alive!');
    http.createServer(app).listen(app.get('port'), function(){
        console.log('Express server listening on port:', app.get('port'));
    });
}); 

// If the coection throws an error
mongoose.coection.on('error',function (err) {  
    console.log('Mongoose default coection error: ' + err);
    process.exit(0);
}); 

// When the coection is discoected
mongoose.coection.on('discoected', function () {  
  console.log('Mongoose default coection discoected'); 
});

Now inside my controller/customer/router.js Controller file,

router.put("/addstud/:route", function(req,res,next) {

var custId = req.user.id;
var studList = req.body;
var route = req.params.route;

mongoose.coection.on('open', function() {
    // Never goes inside this 
    console.log('Mongoose opened.');
});

mongoose.coection.once('open',function(err,co) {
    // Nor this
}

});

But inside the same class i can easily retrieved and add data to Db using Mongoose Model.