Both male and female managuense will display the vertical barring from time to time. Some darker and more pronounced than others. Some will have complete vertical bars from dorsal to anal, others are more like the one in the posted pic in the first post. And this may change with time and mood. Some juvenile males may turn nearly completely black until they are sure of their surroundings. This sometimes happens to jags as large as 6" or 7", usually not in full grown adults over 12". This black coloration can last for months. Nothing to worry about.
As a rule, male managuense will be spotted nearly all over their entire body, even at as small as 4". Females will be spotted mostly on the top half of their body with very little to none on the lower half.
Some species of jags may be more yellow, some may be more of a whitish color as the one in the first post, and yet still more may be more of a golden color. This coloration mainly depends on genetics and geography.
The jag in the first post is decidedly female and in no way a hybrid. 100% typical female jag.