it shouldnt be other fishes......mostly the parent will protect the eggs.after the angels spawn....you can try and do a netting...to net the eggs area. for me i'm using spawning cone,so will just put in a round shape cone to protect the eggs.but mostly my angel parent do very well in taking care the eggs....unless some stupid go and disturb the parent.....another thing might happen...the eggs was just been replace by the parent only...try to look around in the tank.