Cichlasoma nicaraguensis is a wonderful medium size cichlid from Central America. One neat thing about this species is that the female is really more beautiful then the male, not a typical cichlid trait. They are substrate spawners that lay non-adhesive eggs. They have a wonderful pair bond and are good parents.
What I found most fascinating is there relationship in the wild with Parachromis dovii and Neetroplus nematopus. They are all favorites of mine.
This cichlid doesn't get too large, not overly aggressive, good color, great parents. Everyone should work with them at least once, they are quite rewarding.