   drawCircle: ( x, y, radius, color ) -> @drawArc x, y, radius, color, 0, tau
   drawArc: ( x, y, radius, color, start, end ) ->
     return unless radius > 0
-    ctx = @universe.ctx
+    ctx = @ctx()
     ctx.beginPath()
     ctx.arc x, y, radius, start, end
     ctx.fillStyle = color

    [ start, end ] = if left then [ @angle, @angle + Math.PI ] else [ @angle - Math.PI, @angle ]
    [ x, y ] = @edgePoint point, rad + @radius
    @drawArc x, y, rad, @bodyColor, start, end
  calcEarSize: ->
    ratio = @auditoryRange() / @genes.auditoryRange[2]
    size = ratio * @radius / 3

  drawTail: ->
    a = @angle + Math.PI
    [ x1, y1 ] = @edgePoint a
    [ x2, y2 ] = @edgePoint a, @radius + @tailSize
    c = @ctx()
    c.beginPath()
    c.moveTo x1, y1
    c.lineTo x2, y2
