1) Fish 
Kurtus is a genus of perciform fishes, called the nurseryfishes, forehead brooders, or incubator fish, notable for carrying their egg clusters on hooks protruding from the forehead (supraoccipital) of the males. Kurtus is currently the only known genus in the family Kurtidae. In addition to the egg hook, the kurtid gas bladder is enclosed in a tub...