Monogamy is rare in fishes and is usually associated with elaborate parental care. When parental care is present in fishes. it is usually the male that is responsible. and it is believed that there is a relationship between the high energetic investment and the certainty of paternity (except in the case of sneaker males). https://www.jmannino.com/quick-save-Arcade-Smokey-Bear-Belt-p10222-great-pick/