...at least to female fish seeking a mate. Having a pack of offspring nearby is a good way for some male fish to find a mate.
Of course, some males can't be bothered with the real work, and have developed "fake" offspring that fool females into mating with the phony dads. The fakes can be elaborate appendages that look like eggs or baby fish.
Similar things seem to work for people. Women prefer men who like children and can identify them just by looking. But the good daddies don't get all the benefits. For short-term flings women choose manly men with high testosterone levels--again just by looking.