Picture of a Pregnant Mouthbrooding Yellow Striped Cardinalfish
Ostorhinchus cyanosoma, commonly known as the yellow-striped cardinalfish, goldenstriped cardinalfish, or the orange-lined cardinalfish grows to be an average of 6 centimeters.
Yellow Striped Cardinalfish is a paternal mouthbrooder. This is likely to be a more important reason for the sexual dimorphism shown by the male’s wider gape and more protruding lower jaw, than its female counterpart. A bigger mouth allows for more eggs to be protected from predation, and for better water circulation (for oxygenation in both eggs and parent).
Pair bonding in Yellow Striped Cardinalfish does not appear to provide the expected genetic benefits of monogamy, indeed like many pair bonding fishes in its family, predation seems to have driven it rather than reproductive exclusivity.