海葵不出来怎么办

330fish.js:52 Uncaught TypeError: Cannot read property 'draw' of undefined 

aneobj.prototype.draw = function(){

    for(var i=0;i<this.num;i++){
        ctx2.beginPath();
        ctx2.moveTo(this.x[i],cHeight);
        ctx2.lineTo(this.x[i],cHeight - this.len[i]);
        ctx2.lineWidth = 20;
        ctx2.linCap = "round";
        ctx2.strokeStyle ="purple";
        ctx2.stroke();
    }

function gameloop(){
    requestAnimFrame(gameloop);
    var now = Date.now();
    deltaTime = now - lastTime; 
    lastTime = now; 

    drawBackground();

    ane.draw();

}