I have a momentary flashing problem in this short animation when the object is at 180 degrees. There is no logic to it. Any ideas?

/*Animation with strange flash at 180 degrees*/

Fish indecisiveFish;        
FishReverse indecisiveFishReverse;            
float fishAngle;

void setup () {      
  size (screen.width*3/4, screen.height*5/6);      

  fishAngle=245.0;
 
  indecisiveFish=new Fish (color (255, 40, 10));   
  indecisiveFishReverse=new FishReverse (color (255, 40, 10));      
}      


void draw() {     
  background (0, 170, 250);      

 
  float angleCondition=fishAngle/180;       // declare and create a variable that calculates the division of the angle of the cos and sin movement by 180 to determine the condition when the fish changes direction
  int angleConditionConvertedtoInteger = int (angleCondition);       // convert this variable from a float type to an integer type

  if (angleConditionConvertedtoInteger%2==0) {       // create a condition that uses the remainder of the division of this variable to determine the direction of the fish so that if the remainder is an even number, the fish swims back
    indecisiveFishReverse.move ();       // move the reverse indecisive fish so that it looks like it is swimming back towards the start line
    indecisiveFishReverse.display ();       // draw the reverse indecisive fish so that it looks like it is swimming back towards the start line
  }   

  else {       // create a condition that uses the remainder of the division of this variable to determine the direction of the fish so that when the remainder is an odd number, the fish swims forward
    indecisiveFish.move();       // move the indecisive fish in its forward direction so that it swims towards the finish line
    indecisiveFish.display();       // draw the indecisive fish in its forward direction so that it swims towards the finish line
  }    
}      


// Fish class

class Fish {      

   float fishX;
  float fishY;
  color clrFish;
  float fishAngleSpeed;
  float fishCenterX;
  float fishCenterY;
  float sizeArcFishMoveX; 
  float sizeArcFishMoveY;
  float fishLocX;
  float fishLocY;
  float speedXFish;

    Fish (color clrFishtemp) {       //constructor for the Fish class

    clrFish=clrFishtemp;     
    fishAngleSpeed=0.4; // assign a value of 0.4 to the change of angle used in the cos and sign wave movement of the fish
    fishCenterX=0.0;  // assign a value of 0 to the variable that will determine the X position from which the cos motion occurs for the fish
    fishCenterY=height/2; // assign a value of half the height of the canvas to the variable that will determine the Y position from which the sin  motion occurs for the fish
    sizeArcFishMoveX=width/3; // assign a value of a third of the width of the canvas to the variable that will determine the radius of the cos wave motion of the fish
    sizeArcFishMoveY=height/3; // assign a value of a third of the height of the canvas to the variable that will determine the radius of the sin wave motion of the fish
  }      

  // method to move the Fish

  void move () {
    fishX=fishLocX+speedXFish;
    fishY=fishLocY;
    fishLocX=fishCenterX+sizeArcFishMoveX*cos(radians(fishAngle)); // assign a cos wave movement to the variable that determines the X location of the fish in the animation
    fishLocY=fishCenterY+sizeArcFishMoveY*sin(radians(fishAngle)); // assign a sin wave movement to the variable that determines the Y location of the fish in the animation
    fishAngle+=fishAngleSpeed; // increment the angle of the fish cos and sin wave movements by 0.4
    speedXFish+=(random(0.1, 0.8)); // assign a value that is a random value to move the fish horizontally across the screen
  }

  // method to display the Fish

  void display () {      
    fill(clrFish);
    stroke(1);
    strokeWeight (3);
    beginShape();
    vertex(fishX, fishY);
    vertex(fishX+50, fishY+40);
    vertex(fishX+105, fishY+20);
    vertex(fishX+150, fishY+50);
    vertex(fishX+90, fishY+80);
    vertex(fishX+55, fishY+70);
    vertex(fishX+30, fishY+90);
    endShape(CLOSE);
    arc (fishX+116, fishY+42, 10, 15, 0, PI);
  }    
}      



// Reverse Fish subclass of the superclass Fish

class FishReverse extends Fish {      


  // constructor for the class called Fish Reverse

  FishReverse (color clrFishtemp) {      

    super ( clrFishtemp);
  }     

  // method to display the Fish Reverse

  void display () {
    fill(clrFish);
    stroke(1);
    strokeWeight (3);
    beginShape();
    vertex(fishX, fishY+50);
    vertex(fishX+45, fishY+20);
    vertex(fishX+100, fishY+40);
    vertex(fishX+150, fishY);
    vertex(fishX+120, fishY+90);
    vertex(fishX+95, fishY+70);
    vertex(fishX+60, fishY+80);
    endShape(CLOSE);
    arc (fishX+34, fishY+42, 10, 15, 0, PI);
  }
}