Appearance and sexual dimorphism
The wild-type of the species has a yellow-green background colour punctuated with blue dots that extend into the dorsal, anal and caudal fins. Wild-type specimens also have seven faint, interrupted dark vertical stripes on the flanks and one stripe vertically downwards across the head through the eye. The vertical stripe through the eye aside, the second bar on the flank is frequently the most intense, appearing as a dark black spot in the relatively unbarred, aquarium-bred strains of the species. The species is sexually dimorphic, females being smaller in size, having more pink pigmentation on their ventral region and having less developed fin rays in the anterior region of the dorsal fin. Males reach a maximum length of 7 cm (2.7 in).
Distribution and habitat
Unlike their relatives in the genus Apistogramma, the natural habitat of M. ramirezi occurs in the warm, (25.5-29.5 ºC, 78-85 ºF), acidic (pH 5) water courses in the llanos savannahs of Venezuela and Colombia.[5][7][10] The water at sites were M. ramirezi has been found to occur is generally slow-flowing, contains few dissolved minerals, and ranges in colour from clear to darkly stained with tannins. The species is typically only found where cover in the form of aquatic or emerse vegetation is available.
Reproduction
Once sexually mature, the species forms monogamous pairs prior to spawning. 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 ºC (84.2 ºF). The larvae are not free-swimming for 5 days after which they are escorted by the male or the female in dense school for foraging.
Taxonomy, collection and etymology
The species is named after Manuel Ramirez, an early collector and importer of the species for the aquarium trade.[12] George S. Myers and R. R. Harry (1948) originally described the species as Apistogramma ramirezi though the species was latter moved to and from various genera including: Microgeophagus, Papiliochromis, Pseudoapistogramma and Pseudogeophagus.
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 changes assists with minimising 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.
