Appearance and sexual dimorphism
Wild ram cichlids are often more colorful than the tank bred counterparts, which suffer from poor breeding and also being injected with hormones for more color, although this makes as many as one in four males infertile. Male specimens of the ram usually have the first few rays of the dorsal fin extended, but breeding has made some females also show this. There is also the fact that, when close to spawning, female rams have a pink or red blush on the abdomen. Females also have a blue sheen over the spot just below the dorsal fin, and males do not show this. Males reach a maximum length of seven centimeters, and females are usually slightly smaller. (Please note that the black spot method of sexing does not apply for the golden and electric blue varieties of the species.)
The natural habitat of M. ramirezi occurs in the warm, (25.5-29.5 °C, 78-85 °F), acidic (pH 5) water courses in the llanos savannahs ofVenezuela and Colombia. The water at sites where M. ramirezi has been found is generally slow-flowing, contains few dissolved minerals, and ranges in color from clear to darkly stained with tannins. The species is typically found where cover in the form of aquatic or submersed vegetation is available.
Once sexually mature, the species forms monogamous pairs prior to spawning and the males do not tolerate other males. The species is known to lay its small 0.9 - 1.5 mm, adhesive eggs on flattened stones or directly into small depressions dug in the gravel. Like many cichlids,M. ramirezi practices biparental brood care with both the male and the female playing roles in egg-tending and territorial defense. Typical clutch size for the species is 150-300 eggs, though larger clutches up to 500 have been reported. Parental M. ramirezi have been observed to fan water over their eggs which hatch in 40 hours at 29 °C (84.2 °F). The larvae are not free-swimming for 5 days after which they are escorted by the male or the female in a dense school for foraging.[
The ram cichlid is a popular cichlid for the tropical freshwater, community aquarium although it is not necessarily the easiest cichlid to maintain in many situations. This is because the species is often kept with other fish that are more assertive, aggressive or overly active. The species is innately shy and is best kept with passive dither fish, such as neon or cardinal tetras. The species will readily exhibit breeding behaviours in water of pH 5.0-6.5, though softer water encourages more regular spawning. It is easier to maintain the species in larger aquaria as the species is intolerant of common aquarium pollutants such as nitrate. The aquarium should be decorated to mimic the natural environment and is best decorated with several densely planted regions of aquatic plants, separated by open water. The species is prone to filial cannibalism of its brood if distressed. As the water must be free of pollutants, aquarium filtration is important, though water movement should not be extreme. Removing and replacing small amounts of water assists with minimizing the quantities of these pollutants and should be conducted regularly.
Numerous strains of M. ramirezi have been developed in Asia for the fishkeeping hobby. These include numerous xanthistic forms, known as gold rams, along with larger, high-bodied and long-finned varieties. Many of these varieties suffer from lower fertility, health problems or reduced brood care in comparison to wild-type specimens.