Amphilophus citrinellus - AbsoluteAstronomy.com

Amphilophus citrinellus is a large cichlid

Cichlid

Cichlids are fishes from the family Cichlidae in the order Perciformes. Cichlids are members of a group known as the Labroidei along with the wrasses , damselfish , and surfperches . This family is both large and diverse. At least 1,300 species have been scientifically described, making it one of...

fish

Fish

Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...

endemic to the San Juan River and adjacent watersheds in Costa Rica

Costa Rica

Costa Rica , officially the Republic of Costa Rica is a multilingual, multiethnic and multicultural country in Central America, bordered by Nicaragua to the north, Panama to the southeast, the Pacific Ocean to the west and the Caribbean Sea to the east....

and Nicaragua

Nicaragua

Nicaragua is the largest country in the Central American American isthmus, bordered by Honduras to the north and Costa Rica to the south. The country is situated between 11 and 14 degrees north of the Equator in the Northern Hemisphere, which places it entirely within the tropics. The Pacific Ocean...

. In the aquarium

Aquarium

An aquarium is a vivarium consisting of at least one transparent side in which water-dwelling plants or animals are kept. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, marine mammals, turtles, and aquatic plants...

trade A. citrinellus is often sold under the trade name of Midas cichlid. A. citrinellus are omnivorous and their diet consists of plant

Plant

Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...

material, molluscs and smaller fish

Fish

. The species is closely related to but not to be mistaken as Amphilophus labiatus
Amphilophus labiatus
Amphilophus labiatus is a large cichlid fish endemic to Lake Managua and Lake Nicaragua in Central America. In the aquarium trade A. labiatus is often sold under the trade name of red devil, a common name which they share with Amphilophus citrinellus.-Appearance:Colouration in wild specimens is...

.

Midas Cichlids are heavily built and are capable of standing up to any other aquarium-sized cichlid in fights over territory. They have powerful jaws, sharp teeth and a physical size advantage in comparison to other aquarium species. Therefore, the aggressivity of Midas cichlids should not be underestimated and co-habitants should be chosen carefully in an aquarium setting.

Considerable debate over the taxonomic status of A. citrinellus began soon after the discovery of this species in the nineteenth century and continued throughout the twentieth century. A multivariate approach to treatment of anatomical characters has facilitated the discrimination among very similarly shaped species, aided by behavioral and ecological evidence. Multiple species of this group have been identified and verified by genomic and mitochondrial DNA evidence in volcanic crater lakes Apoyo (see Apoyo Lagoon Natural Reserve

Apoyo Lagoon Natural Reserve

Laguna de Apoyo Nature Reserve is a nature reserve located between the departments of Masaya and Granada in Nicaragua...

) and Xiloa. The genetic evidence from Apoyo supports a hypothesis that the six known species of the lake evolved via sympatric speciation. A few to perhaps several dozen species fitting the biological species concept are considered to exist among what has historically been called A. citrinellus, the great majority of which have not been described to date. The nine most recently described members of this species complex are considered endemic to their respective small, volcanic crater lakes.

Colouration in wild stocks is variable, with most specimens grey to olive brown with a characteristic pattern of black dorsolateral bars, some pink, white, yellow or orange specimens do occur. These brightly colored forms, often called "golds", exist in nature at varying frequencies throughout the range of the species group. Colorations and morphological characters (e.g. accentuated nuchal humps) seen in the hobbyist trade are the product of selective breeding for several generations and may not be reflected in the wild.

The conservation status of only one species of this group has been analyzed. The arrow cichlid (Amphilophus zaliosus) was evaluated as Critically Endangered by the IUCN Red List. Among the small body of information regarding populations of the species of this group, four other species may have smaller populations and/or ranges than this fish in Laguna de Apoyo: Amphilophus flaveolus, Amphilophus chancho, Amphilophus supercilius, and Amphilophus globosus. The final member of the complex, Amphilophus astorquii, constitutes about eighty percent of the breeding population of Laguna de Apoyo.

See also