| Mayan cichlid | |
|---|---|
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Perciformes |
| Family: | Cichlidae |
| Subfamily: | Cichlasomatinae |
| Genus: | Cichlasoma |
| Species: | C. urophthalmus |
| Binomial name | |
| Cichlasoma urophthalmus Günther, 1862 |
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The Mayan cichlid, Cichlasoma urophthalmus, is a member of the Cichlidae family of fish. It is also known as the mojarra castarrica in its native Mexico. It has interesting colors, with its eight black bands (starting just behind the eye) and its large ocellus (eyespot) on the caudal peduncle (base of the tail), which gives it its scientific name. It has a base color of brown to red that becomes more intense during breeding. As in many animals, the red color is much more brilliant in wild specimens than captive ones, but one can help maintain some of its vibrance by feeding the fish live foods and foods that contain Vitamin A, which breaks down into the red pigment beta-carotene in the body. Previously, this species was a member of the genus Cichlasoma and the subgeneric section Nandopsis. However, the genus Cichlasoma is in revision and has been restricted to the 12 species of South American cichlids related to Cichlasoma bimaculatum. Thus, many of the approximately 100 species that were formerly members of Cichlasoma have yet to be formally assigned to a new genus, and are conventionally referred to as "Cichlasoma" for the time being, with the subgeneric section tentatively intended as the new genus. Thus, the Mayan cichlid is identified here as both Cichlasoma uropthalmus and Cichlasoma (Nandopsis) urophthalmus in accord with the convention for taxonomically undetermined cichlids (Kullander 1983, Stiassny 1991).
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The Mayan cichlid reaches a maximum standard length of 280 mm (Conkel 1997). It is native to the Atlantic slope of tropical Mesoamerica (Central America), ranging from eastern Mexico southward to Nicaragua (Miller 1966). It was first recorded from Everglades National Park, Florida in 1983 (Loftus 1987), and is now a common nonindigenous fish in southern Florida (Bergmann and Motta 2004, 2005). Eight subspecies of Cichlasoma urophthalmus are recognized throughout Central America (Caso Chavez et al. 1986): aguadae, trocheli, cienagae, ercymba, amarum, zebra, conchitae, and mayorum.
In its native range, the Mayan cichlid is a popular food fish. For this reason it is the basis of a regional fishery, is commonly used in aquaculture, and is among the most-studied of the Neotropical cichlids (Martinez-Palacios et al. 1993). To date, the Mayan cichlid has been most intensively studied at localites in southeastern Mexico on or near the Yucatan Peninsula (Caso Chavez et al. 1986; Martinez-Palacios and Ross 1986, 1988, 1992; Flores Nava et al. 1989; Martinez-Palacios et al. 1990, 1993, 1996; Salgado-Maldonado and Kennedy 1997; Vidal-Martinez et al. 1994; and Gamboa-Perez and Schmitter-Soto 1999). The Mayan cichlid inhabits lakes, rivers, rocky shorelines, lagoons, esturaries, coastal islands, red mangrove Rhizophora mangle swamps, and turtle grass Thalassia testudinum flats off the mainland. It can be found in oxygen-rich areas near submerged vegetation and over muddy substrates. However, despite its preference for waters with dissolved oxygen content of at least 3.5 mg/L, it is capable of surviving in extreme hypoxia. This is because it is an oxygen conformer, becoming much less active in hypoxic water, and even surviving virtual anoxia for up to two hours (Martinez-Palacios and Ross 1986, Gamboa-Perez and Schmitter-Soto 1999).
The Mayan cichlid is philopatric, or site tenacious, i.e. - individuals are non-migratory and prefer to stay within a home range (Caso Chavez et al. 1986, Salgado-Maldonado and Kennedy 1997, Faunce and Lorenz 2000). The Mayan cichlid has a minimum temperature requirement of about 14 degrees Celsius (Stauffer and Boltz 1994). In its native range, it inhabits waters with temperatures from 18 - 34 degrees Celsius, but its optimal temperature range is 28 - 33 degrees Celsius (Caso Chavez et al. 1986, Martinez-Palacios et al. 1996). The Mayan cichlid is capable of surviving in a variety of conditions. It is euryhaline and can survive in a range of salinity from 0 - 40 ppt (Martinez-Palacios and Ross 1992, Martinez-Palacios et al. 1993). Experiments on captive specimens have shown that it can tolerate abrupt increases in salinity of up to 15 ppt (Martinez-Palacios et al. 1990). The Mayan cichlid has a broad range of tolerance to abiotic conditions and a broad behavioral repertoire to enable it to feed on a variety of foods. This species is also a dietary generalist, consuming organisms from a variety of disparate taxa (Caso Chavez et al. 1986, Martinez-Palacios and Ross 1988). However, it is susceptible to malnourishment, apparently due to the requirement that a relatively large proportion of its diet be animal prey (Flores Nava et al. 1989, Martinez-Palacios et al. 1993).
The Mayan cichlid is territorial and aggressive when breeding (Sands 1987, personal observations). As parents, Mayan cichlids are highly protective of their young, and they have several broods per year. This species is a monogamous, biparental substrate spawner that exhibits minimal sexual dimorphism and guards its fry (babies) for up to six weeks. All of these traits are greatly developed and represent an extreme in the general pattern found in the genus Cichlasoma (Barlow 1991, Martinez-Palacios and Ross 1992, Martinez-Palacios et al. 1993, Conkel 1997, Faunce and Lorenz 2000). In Mexico, the Mayan cichlid spawns for a nine-month period from March to November, particularly during the wet season from June to September. This corresponds to a period when the water temperature is at least 24 degrees Celsius (Caso Chavez et al. 1986, Martinez-Palacios and Ross 1992, Martinez-Palacios et al. 1993). Multiple broods are raised per year. The fry appear to be adapted to lotic (flowing) water. They exhibit strongly positive geotactic behavior, actively swimming down to the substrate upon hatching from the egg and adhering themselves to the bottom by means of three pairs of mucous glands (Martinez-Palacios et al. 1993).
The Mayan cichlid is a somewhat obscure but popular aquarium fish in the United States. In captivity it exhibits interesting behavior, whether it is breeding or not. It is rather difficult to tell the sexes apart in the Mayan cichlid, because there is minimal sexual dimorphism (shape) and dichromatism (color). However, among fish of the same age, the males tend to be a little bit larger than the females. The colors of Mayan cichlids in breeding dress may also vary slightly. Males may have a slightly more vibrant red, and females may have a slight greenish sheen on their flanks. Once they are ready for breeding and their whitish spawning tubes protrude from the bottom of the body, it is somewhat easier to tell the sexes apart. As in other cichlids, the female has a shorter, wider, and blunter vent, while the male's vent is slightly longer, thinner, and more pointed.
The Mayan cichlid's color, size, and behavior make it resemble the red terror cichlid Cichlasoma festae, to which it is fairly closely related. However, the two have separate ranges in nature, with the Mayan cichlid coming from the Atlantic slope of southern North America and northern Mesoamerica, and the red terror coming from the Pacific slope of southern Mesoamerica and northern South America. There are some physical differences, too. The red terror looks a bit more robust overall. It gets to be a bit larger than the Mayan cichlid, attaining a longer and taller body, but with a relatively shorter snout and a slightly larger nuchal hump (bulging forehead). It also has longer trailings on its dorsal and anal fins. The red terror has more dark bands on its body (about nine starting behind the eye, rather than eight), and a smaller ocellus on its caudal peduncle. It also tends to retain more of its red color in captivity than does the Mayan cichlid. However, some red terrors lack the commonly seen bright red base color and have an overall green color with a yellow tinge. The red terror is reputedly the more aggressive of the two species, but both can be very belligerent in an aquarium and can bully or even kill smaller or weaker fish, especially when pairing off for breeding.
Like all large cichlids and other aquarium fishes, and whether kept in a breeding pair or displayed in a community tank, the Mayan cichlid needs a large aquarium with good filtration. In general, unless they are being quarantined because of a disease, social animals like these and most other cichlids should not be kept alone, and they should be provided with enough room to interact safely with other fishes. A 55-gallon aquarium should be regarded as the minimum size for an aggressive, large cichlid like the Mayan cichlid. Even better would be to house these fish in a 70, 100, 120, or even 150-gallon tank. If they are to be housed with other species, the Mayan cichlid's tank mates must be of similar size and temperament. Some good potential tank mates would be other Central American cichlids, such as those from the Amphilophus group (the Midas cichlid, Amphilophus citrinellus, and the red devil cichlid, Amphilophus labiatus), and the Theraps group (the black belt cichlid, C. maculicauda, the redheaded cichlid C. synspilum, and the redspotted cichlid C. bifasciatum). It is not advisable to house the Mayan cichlid with other cichlids from the Nandopsis group, such as the jaguar cichlid, Parachromis managuensis, the wolf cichlid, Parachromis dovii, or the Motagua cichlid, Parachromis motaguensis. Because they are more closely related, the Mayan cichlid may perceive these species as too similar to itself and as a threat, which may lead to dangerous fighting for both the Mayan cichlid and its opponent. Other fishes that may be compatible with the Mayan cichlid are large Neotropical catfishes, such as the suckermouth armored catfish of the Loricariidae. This family includes favorite aquarium denizens like Hypostomus plecostomus and Pterygoplichthys pardalis. . But be forewarned: this fish will eat fish small enough to fit in their mouths.
As with most Neotropical cichlids, a breeding pair of Mayan cichlids should be kept on their own to avoid injuring other fish, as well as to avoid stressing the parents to the point of turning on each other or their brood. The only reason to keep a breeding pair in the company of others is so that they have "target fish" on which to focus their aggression, which can help strengthen the pair bond and increase the motivation to protect the territory and the babies. As with other territorial fishes, one way to keep the aggressive parents in the same tank as other fish is to separate them with a plastic screen or mesh, such as egg crate. The fish can see one another, and even smell and taste one another through the mesh, but are unable to injure each other. However, this latter arrangement is more appropriate for introducing belligerent breeding partners, or for separating incompatible community tank mates, than it is for housing a breeding pair. This is because the baby fish are likely to swim to the other side of the barrier and get eaten, and the parents might still get too nervous. A safer approach is to house the parents in an aquarium right next to the aquarium that contains the other fish. Although unable to smell or taste their opponents, the parents will still see these other fish and perceive them as a threat like any other target fish. A barrier to vision, such as a piece of cardboard, can be placed between the tanks to give the parents a break from aggressively defending their territory from time to time. Another way to achieve this illusion of a community is to hold a mirror up to the parents' aquarium for short periods. The pair will perceive their reflections as strangers and will feel like "teaming up" to protect their young, but will do no harm to anyone and will not get so stressed out that their pair bond breaks down.
As in most substrate-spawning cichlids, the adults are excellent parents, mouthing the eggs to keep them free of fungi, and then caring for the babies diligently. The young can be reared in much the same way as those of other substrate spawners. They are typically born in broods numbering from about 100-500. They must be given frequent feedings of brine shrimp Artemia nauplii, hard-boiled egg yolk, or infusoria for their first week of life. After that they can be given finely powdered flake food and frozen food along with their parents. The parents will often guard the babies for a month, after which time the babies can be removed from their parents' care and placed in their own separate aquarium. They can remain there until they reach about 2 inches (5 cm), at which time they will be ready to be kept with other fish of similar temperament.
Whether kept for breeding or viewing, the Mayan cichlid is an interesting fish. It sports beautiful colors and patterns, and has complex behavior for the aquarist to observe, admire, and study. However, because of its special requirements, it is not suitable for the novice aquarist. But when kept with plenty of space, a good diet, and compatible tank mates, the Mayan cichlid can provide years of enjoyment for its human keepers.