What is a guapote? The term is applied in Central America to a group of large, attractively marked carnivorous cichlids ecologically analogous to the large and small mouthed basses of North America. More specifically, it refers to a number of the large species that according to Kullander (1996) can be referred to the genus Parachromis and to the monotypic Petenia splendida, whose highly specialized protractile jaw apparatus sets it apart from other Heroine sensus Kullander neotropical cichlid species. These robust cichlids share the role of top carnivore in the fresh water fish communities of most of southern México and Central America with the garpikes of the genus Lepisosteus and the pimelodid catfishes of the genus Rhamdia. Their position at the apex of the trophic pyramid is challenged only in the San Juan basin of Nicaragua, where both the Great Lakes and the Rio San Juan are home to a trio of marine intruders, the sawfish, the bull shark and the tarpon. It is, therefore, no exaggeration to say that these cichlids are considerably more interesting to the fisherman than to the average aquarist, a fact that has led to the transplantation of several species to suitable habitats outside their natural ranges. All these cichlids are important food fishes in their countries of origin, and friends who have partaken of them tell me that they are superb eating. (For the benefit of the morbidly curious, I have indulged in cichlidophagy, having eaten a wide range of tilapias in Africa and surplus Midas cichlids from laboratory stocks in Berkeley. While not in the same league as Nile perch, the cichlids I have sampled lived up to their gustatory reputation in a most satisfactory fashion.)
The genus Parachromis is an assemblage of medium-sized to very large Heroine cichlid species characterized by large, obliquely placed, more or less strongly protractile jaws. Regan (1905), then considering these species as part of the Cichlasoma subgroup Parapetenia, recognized a gradation of specialization with regard to the elaboration of the enlarged pseudocanines teeth in the anterior portion of both jaws. In the most advanced forms, the anteriormost pair of pseudocanines in the upper jaw are greatly enlarged, the posterior two pairs decreasing progressively in size. In the lower jaw, the pattern is reversed, producing a highly efficient mechanism for seizing and holding the small fish upon which these cichlids prey. Regan himself apparently felt that his initial definition was a bit too broad and subsequently re-assigned some nominal Parapetenia to other subgenera (1907) a trend continued by Eigenmann (1924), who moved the three representatives of the group from northwestern South America to the subgenus Astateros. The genus Parachromis as presently understood comprises mainly the more specialized piscivores originally placed in Parapetenia by Regan.
For the purposes of this article, I will restrict the limits of the species covered to those of the genus Parachromis and Petenia. To comprise a suite of piscivorous species characterized by large mouths, moderately protractile jaws armed with enlarged pseudocanine teeth and a color pattern that comprises the following elements:
- A midlateral band that is either retained intact through the attainment of sexual maturity or that fragments into a series of large, irregular black lateral blotches in adults.
- A well-developed ocellated opercular spot.
- The presence of vermiculate markings on the head, flanks or both areas in adults of one or both sexes.
The sexes are strongly dimorphic, females being both smaller and less brilliantly colored than males during periods of sexual activity. There is, additionally, a strong tendency towards female dominated or exclusively female brood care under certain circumstances (Sterba, 1966; Meral, 1973). The accompanying table lists the representatives of the genus Parachromis, as well as information on their distribution natural history, and status as aquarium fish. Reference to the range maps accompanying the text will reveal an Antillean-Central American distribution for this assemblage of species.
It may seem an insult to the reader's intelligence to state that very large (>200 1) aquaria are absolutely necessary in order to maintain any giant predatory cichlid correctly, but the lack of any significant correlation between the number of baby oscars and the number of large tanks sold yearly suggests that there are still quite a few aquarists who have yet to get the message. Even a single adult specimen of any of these cichlids must have a minimum of 200 1 of living space. Anything smaller is the aquaristic equivalent of the infamous "tiger cages" used to house prisoners during the Vietnam War. Questions of adequate swimming space aside, these cichlids place such demands on the management of the nitrogen cycle in their aquaria that housing them in any lesser volume of water provides absolutely no margin in case of accidental fouling. It is no coincidence that interest in these cichlids as aquarium fish coincided with the availability of moderately priced large aquaria. The aquarist unwilling, or unable, to provide such quarters should turn his attentions to the numerous more easily housed members of the family Cichlidae.
It follows from the foregoing that managing the nitrogen cycle properly is the biggest challenge facing the keeper of these giant cichlids. While not otherwise picky about water conditions, guapotes do not tolerate high levels of dissolved nitrite and ammonia. When stressed in this fashion, they become skittish or reclusive, chafe frequently against vertical surfaces or the bottom of their quarters, and undergo a darkening of their coloration. Amazing to relate, they even loose their normally gargantuan appetites! Unless the situation is corrected promptly, prolonged exposure to such physiologically stressful conditions will weaken the fishes' resistance to pathogenic agents, leading to eventual death from systemic bacterial infections. The only realistic approach to managing the nitrogen cycle in aquaria housing such large, voracious fishes involves the use of a very efficient outside power filter in conjunction with a program of frequent, regular partial water changes. The sheer volume of their excretory products overwhelms biological filters and degrades the capacity of chemically active media so rapidly that it makes such an approach economically prohibitive to implement. Because the effectiveness of mechanical filtration is a direct function of how frequently the filter media are cleaned, a reusable medium such as EhfiFixTM is the only sane alternative under conditions of rapid clogging. Dacron or other synthetic filter flosses may cost less initially, but within a relatively short time, the cost of replacing them will exceed the higher purchase price of the EhfiFixTM. Aquarists differ among themselves on the optimal schedule of filter and water changes to employ with large cichlids. As the majority of the disputants seem to enjoy a comparable degree of success in maintaining and breeding their fish, one may suspect that the consistency with which a particular regime is followed is probably more important than the details of its organization. My own preference is to clean the filter whenever it seems to need it and change 40% - 50% of the aquarium volume every ten to fourteen days.
Though they will prosper over a temperature range of 20°C - 30°C, the prudent guapote keeper will house his pets at the low end of the range unless his object is to induce spawning. At 20°C -22°C, these cichlids are metabolically less active than at higher temperatures. In consequence, their appetities are reduced and as an inevitable corollary, so is their output of metabolites. This makes managing the nitrogen cycle somewhat easier while saving on the grocery bill. Of equal importance if the fish are housed in a community situation, guapotes are significantly less aggressive at the lower end of their optimum temperature band.
Unlike some predatory fishes, guapotes do not insist that their food be alive and splashing. This makes them somewhat easier to satisfy at feeding time than are leaffishes or pike characins, as they will accept any meaty foods offered to them in sizable chunks. Most guapote keepers base their pets' adult diet upon pelletized trout chow or one of the semi-moist cat kibbles currently on the market, supplemented by frozen fresh items such as beef heart and fish filets chopped to an appropriate size. Live foods in the form of earthworms, fish, grass shrimp or crayfish are usually offered as treats. My personal view is that these cichlids should be given as much live food as budgetary considerations permit, particularly if one aims at conditioning them for a spawning. Besides being both nutritionally and psychologically beneficial, live foods are generally less messily consumed and thus result in the release of less fine particulate organic matter, whose breakdown complicates management of the nitrogen cycle in the fishes' aquarium. Whatever foods are offered to them, guapotes display heroic appetites that are more readily appeased with a series of small daily feedings than in a single heavy meal.
When fed to satiety with live fish, captive Parachromis dovii, P. managuense and P. motaguensis display a behavior pattern that appears totally unique among fishes. These guapotes will continue to capture prey, but instead of killing and attempting to swallow them, they will carry small fish around inside their mouths for up to 6 hours, working them backwards into the pharyngeal mill one at a time as the digestion of previously consumed prey progresses. The efficiency of such a system of food storage cannot be questioned though it is a trifle disquieting to look into the partially open mouth of such an individual and see a number of little fishy faces peering right back! Another behavioral peculiarity related to feeding shown by captive individuals is the tendency to refuse spiny-finned prey fish after having been fed such soft-finned prey items as mosquito fish and small goldfish. As guapotes feed upon both soft finned (poeciliids and characins) and spiny finned (smaller cichlids) prey in nature, being very well equipped with the necessary pharyngeal mill to handle both types of food, such behavior in captivity clearly reflects nothing more than an individual's dining preferences. As preference is strongly affected by motivation the frequently heard observation that a particular guapote will eat only goldfish tells me much more about the fish's success in training its keeper than it does about the food value of that particular item. If one has the wherewithal to cater to such trophic whims, there is clearly no harm in doing so. However, if one wishes to use one of these giant predators as an ecologically sound means of disposing of undesirable fish or else must rely upon a wide range of live foods for other reasons, such behavior cannot be allowed to persist. When confronted by such a selective response to food by a guapote, simply raise the tank temperature to 25°C and discontinue feeding for a few days. Appetite being the best sauce, previously rejected food items are usually taken with alacrity when offered at the end of such an enforced fast.
Virtually everything that has been said elsewhere about the tendency of large cichlids to rearrange their immediate environment (Mortensen, 1978; Loiselle, 1980) applies in spades to the guapotes. It's not that they are any more given to moving gravel and pushing rocks over than are Red Devils or Chanchitos. The problems mainly arise from their larger size, which makes them so much better at this sort of underwater demolition than smaller relatives. However felicitous such a combination or inclination and ability may be in nature, it can have disastrous consequences in captivity, where the fall of a misdirected piece of rockwork can precipitate the equivalent of Noah's flood. Such a contretemps will almost certainly prove fatal to its perpetrator and his tank-mates and may well have equally dystrophic effects on the marital status of their keeper if the shattered aquarium voided its contents onto anything other than a bare concrete floor! Prudence thus dictates that any rockwork utilized as aquarium furnishings for those cichlids rest securely on the bottom of the tank. If a chunk of rock has any play in it at all, change its orientation until a resting position is found that allows no lateral motion at all. It also is most unwise to position rock-work such that the apex is broader than the base upon which it rests. Such a configuration is very vulnerable to being pushed over by a few solid butts. These considerations apply with equal rigor to furnishings built up from several chunks of rock-work. Additionally, it is unwise to use individual rocks much smaller than a grapefruit in overall bulk in such freestone constructions, for they are too likely to be dislodged from the edifice, again with possibly disastrous results. Once the rock-work is in place, gravel can then be added to the tank. As these fish are not tolerant of rooted plants, there is little to be gained in having a thick layer of gravel in their quarters. A covering no more than 3.0 cm deep will adequately mask the bottom and is less likely to trap fine particles of detritus than is a deeper layer. In my experience, there is no point in going to great pains to impart a particular slope to the gravel in a guapote aquarium. As the fish will invariably move it to suit their own tastes, I simply dump it in and spread it more or less evenly over the bottom.
Individual guapotes will sometimes develop a violent aversion towards filter intake siphons and heaters. Such an individual will try to eject the offending objects from the aquarium with a few vigorous upward flips of the snout. Such efforts, when successful, produce a remarkably faithful imitation of a Poseidon missile leaving its launching tube and result in either an inoperative (and possibly burnt out) power filter or a broken heater.
Other individuals will seize a heater and slam it repeatedly against either the tank walls or a convenient rock until they perceive it to be safely dead. This rarely has any drastic effects upon the fish, but it can have literally electrifying consequences for anyone unfortunate enough to come into contact with the tank water before the broken heater is disconnected! Solitary specimens are the most common offenders in this regard, but some individuals will take offense at these intrusive pieces of glass and plastic tubing even when housed in a community situation.
The only way to prevent such sabotage is to deny the fish access to both intake siphons and heaters. Simply attaching these implements to the tank wall with suction cups, the remedy usually recommended doesn't work very well, as large guapotes can pull them free with very little effort. The best means of protecting these appliances is to fence off the two rear corners of the aquarium with a perforated partition before filling the tank with water. A pre-cut piece of plexiglass with I/4" holes drilled to allow free water circulation or a similarly trimmed piece of plastic egg crate sheeting, cemented in place with silicone elastic sealant will serve this purpose admirably. Any guapote capable of overcoming these protective measures should be donated to the Navy as a candidate for an underwater demolition team!
The final touch required to make an aquarium suitable as a residence for these predators is a secure, tightly fitted cover. Guapotes are often very uncomfortable in new quarters. When faced with any sort of abrupt stimulus they may respond by attempting to jump out of their new home. Juvenile Parachromis dovii and Petenia splendida are particularly given to such behavior, but the prudent hobbyist will anticipate its occurrence in any guapote regardless of age. A screen of floating plants serves to reduce the number of shadows falling onto the bottom of the aquarium and will minimize the likelihood of such precipitous exits, which however adaptive they may be in nature rarely end favorably in captivity. If moving an established specimen into a new tank, taking along a familiar piece of rock-work will often minimize the trauma of changing residence. But the ultimate defense against this sort of fish loss is a cover that physically prevents the animals from jumping out. Given the size of these cichlids, a simple piece of window glass is just not heavy enough to do the job. Either a thicker (and therefore heavier) piece of glass should be used, or else a heavy object such as a brick should be placed on top of the cover to provide the required weight.
Most aquarists assume that because of their large size guapotes cannot be housed safely with other fish. This is not true. Guapotes are no harder to house in a community tank than are members of the red devil-Midas cichlid complex (Loiselle, 1980), with the understanding that they require substantially more swimming room. The most important thing to remember is that with the single exception of P. splendida, these cichlids are exceeding intolerant of conspecifics and not much more enthusiastic about having other guapote species as neighbors. If one bears this fact in mind, there are no serious obstacles likely to be encountered when these single specimens are housed with companions too large to be easily swallowed.
As gaupotitos neither arise by spontaneous generation nor are delivered by the stork, the intolerance these fish display towards conspecifics obviously does not always extend to individuals of the opposite sex. It does, however, pose some very serious obstacles to inducing pair formation in captivity, where even the largest aquaria fall far short of providing the prospective partners with enough maneuvering room to minimize the chance of serious injury or death to one or the other. The aquarist wishing to observe pair formation in a reasonably naturalistic context is best advised to rear 6 to 8 juveniles to maturity in a large cichlid community. The guapotes appear to reach sexual maturity at much smaller sizes in captivity than is the case in nature, somewhere between 8.0 and 12.0 cm SL, depending upon the species in question. In a 400 l aquarium (the bare minimum of space required for such an undertaking) such young adults can usually pair off successfully. Since pair formation is a relatively slow process, the aquarist can usually remove superfluous conspecifics before the courting couple can do them in, while heterospecifics can find adequate space to keep out of their way as they establish a breeding territory. Two such individuals of the opposite sex will also pair up successfully in a community setting, but as sexual maturity usually anticipates the appearance of reliable secondary sexual characteristics, most aquarists find it safer to play the numbers game, which guarantees that they will get at least one pair rather than gambling or picking a male and female from a tankful of young adults.
The infrequent availability of these cichlids through commercial channels often forces the prospective guapote breeder to work with a very small pool of large adult fish. Allowing such prized specimens to pair naturally is rarely a feasible alternative, given the prodigiously large aquaria required to bring the risk of mating mortalities down to an acceptable level. The only workable approach in such instances is to employ the so-called incomplete divider method. To implement this technique, the hobbyist divides the breeding tank in two with either a screen partition or a glass partition that is prevented from resting tightly against the bottom. Given the brute strength of these cichlids, it is critical to secure the partition as strongly as possible and if screening is used, to make certain it can resist the biting and butting to which it will be exposed as the two sexes attempt to get at one another. A suitable spawning site such as a large rock or an 8" diameter flower pot, sectioned vertically and stood on end, is then placed within 15 cm of the partition on the female's side of the tank and each sex is introduced to its quarters.
Generous feeding and the exercise of patience will lead to a spawning in the absence of any direct contact between the partners. While fertilization of the eggs will not be 100% efficient, the size of the spawns is such that if even 50% of the eggs hatch, the aquarist will have far more fry on his hands than he can properly rear. As the female is normally the exclusive egg-tending parent in nature, the male hardly suffers any emotional trauma from this enforced separation. At 25°C, hatching occurs 72-80 hours postspawning and the young, who are often shifted from one location to another thereafter by their mother, are mobile three to four days later. Once free-swimming, they will move freely between compartments, thus affording both male and female the occasion to behave parentally. As parental behavior extends to mauling the extremities of anyone foolish enough to bring them within reach, the prudent aquarist will resort to other means of manipulating objects in a tank containing a guapote pair with progeny.
The free-swimming fry are large enough to take Artemia nauplii and finely divided prepared food as their initial meal. With good feeding, they grow prodigiously. Fry of most species can take Daphnia within a week of becoming mobile, while those of C. dovii can handle adult brine shrimp. They should be fed at least twice daily to assure optimal growth and prevent their grazing on parental mucus from getting out of hand. Sometime between the sixth and eighth week posthatching the distinctive longitudinal striping begins to fragment, a process marked by the onset of serious fighting among the fry. I suspect that parental care in nature probably ceases at this point. If they have not already been separated from their parents, now is the time to do so. Under favorable conditions sexual maturity is attained between 10 to 20 months post-hatching, P. splendida taking rather more time in this regard than the Parachromis species.
Because the fry are such heavy feeders and their intolerance of siblings develops at such an early age, there is little point in attempting to rear a complete spawn of these cichlids. A commercial fish farmer might be able to provide sufficient provender and growing room for 5000 guapote fry, but no other fish breeder can. It is far more sensible to remove 90% to 95% of the fry before they are free-swimming, leaving the parents with a respectable number of offspring to tend than to attempt the impossible task of rearing a whole brood. Unwanted wrigglers can be used as live food for a wide range of fishes. The remaining fry will grow faster and more evenly, and as they will be less crowded will incur fewer fatalities with the inevitable onset of inter-sibling aggressiveness. From the economic standpoint, one is also far more likely to obtain a reasonable unit price for a hundred or so gaupotitos of a given species than for several thousand.
After reading the foregoing, the average aquarist (indeed, any sane person) could hardly be blamed for asking why anyone would want to keep such behemoths in the first place. There is certainly no scarcity of equally colorful cichlids with comparable reproductive behavior from which to choose, whose maintenance is indubitably less costly and certainly less time consuming. The chief attraction the guapotes exert upon an aquarist lies in their highly idiosyncratic and responsive behavior. Particularly when maintained as solitary individuals, these robust predators come to interact with their keepers in many fascinating and highly appealing ways. Many guapote fanciers regard their charges as real pets, asserting that a large P. dovii or P. managuense has every bit as much personality as a dog or a cat and is every bit as intelligent. There is certainly no denying that these fish seem quite capable of responding deferentially to different people and of forging a bond with their keeper that goes well beyond the simple "cupboard love" that characterizes most aquarium fishes. As progressively more people find themselves living in apartments where the more traditional four-footed pets are not permitted, the appeal of such "wet pets" is bound to increase. As long as prospective guapote keepers appreciate that their pets require as much care to remain healthy and happy as do more traditional animal companions, they can look forward to many years of enjoyment from one or more of these hardy, intelligent and highly responsive cichlids.
Petenia splendida Günther 1862
Adult size: Males to 60.0 cm SL. Females, Females to 40 cm. SL
Range: Southeastern México in the Rio Grijalva, extending into the Rio Usumacinta basin through northern Guatemala into Belize (Miller, 1966). The type locality is Lago Peten Itza in Guatemala, hence the generic name. Introduced into the basin of the Rio Papaloapan in the state of Tabasco, México (Sevilla, 1977).
Habitat: Characteristically found in still-water habitats such as lakes, oxbows and coastal lagoons, or the quieter stretches of large rivers. Often found in densely planted biotopes (Klee, 197l; Norris, 1971), or in close association with waterlogged brush or tree trunks (Hubbs, 1935).
Comments: Red individuals of this species occur at numerous localities in Belize. In some places, up to 1/3 of the breeding pairs observed consisted of a normally colored male and a red female (Barlow, pers. comm.). According to Bill Macrum, principal commercial breeder of this species, red P. splendida breed true, but do not begin color metamorphosis until they are at least 10.0 cm SL, at C. one year postspawning. First imported as an aquarium fish into the United States in 1970, P. splendida is often sold under the name by which it is known in Belize, the bay snook.
Parachromis dovii (Günther 1864)
Range: Both Atlantic and Pacific slopes of Costa Rica, Atlantic slope from the Rio San Juan basin of Nicaragua, including the Great lakes northward into eastern Honduras (Miller, 1966, 1976).
Habitat: Clear water biotopes over firm bottoms, either in lakes or rivers. The preference shown by P. dovii for lacustrine habitats has earned it the vernacular name lagunero in Nicaragua. Usually associated with submerged brush piles or waterlogged tree trunks. Juveniles often found in stands of aquatic plants (Meral, 1973). Found to depths of 10 m in L. Jiloa, a crater lake in Nicaragua (Davies and McKaye, 1978).
Comments: Populations of P. dovii in L. Nicaragua and the Rio Puerto Viejo on the Atlantic slope of Costa Rica include orange-red individuals, often marked with irregular black blotches on the body and fins. the first individual of this species imported into the United States as an aquarium fish in 1962, was such an oligomelanic individual. All such fish are large (>25.0 cm SL) (Meral, 1973). Nothing is known of the genetics or ontogeny of oligomelanism in P. dovii.
Pacific slope Costa Rican populations differ from Atlantic slope populations in several details of finnage and color pattem. The possibility exists that they may be recognized as specifically or sub-specifically distinct in the future.
Parachromis managuense (Agassiz 1858)
Synonyms: Parachromis gulosus Agassiz 1859
Range: Atlantic slope of Central America from southern Costa Rica northward to the Rio Patuco, Honduras (Miller, 1966, 1976). Introduced into Lake Amatitlan, Guatemala, the Rio Chamelecon basin in northern Honduras and Lakes Ilopango and Coatepeque, El Salvador (Bleicke, 1972). The type locality is Lake Managua, hence the specific name.
Habitat: Turbid, slow-moving water over soft bottoms. Capable of breeding successfully over a wide range of biotopes, from the small tributaries of larger rivers through seasonally flooded marshes (Bleicke, l 972). Found in close association with rocky bottoms in the Great Lakes of Nicaragua (McKaye, 1977).
Comments: Golden individuals of P. managuense are very infrequently encountered in Lakes Managua and Nicaragua (Astorqui 1971). Their rarity may be due to the fact that contrary to the case in other naturally occurring oligomelanic Neotropical cichlid morphs, the fry of such P. managuense are golden at hatching, which puts them at a substantially greater risk of predation than their normally pigmented counterparts. Oligomelanism in P. managuense is determined by a single gene that behaves as a Mendelian recessive. A complex of polygenic modifiers appears to control the extent of the residual color pattem (Loiselle, l973). First imported into the United States in 1964, P. managuense was the first Central American guapote bred in captivity.
Parachromis motaguensis (Günther 1869)
Adult size: Males to 30.0 cm SL., females to 20.0 cm SL.
Range: El Salvador and both slopes of Guatemala. The type locality is the Rio Motagua, Guatemala, hence the specific name.
Habitat: Quieter reaches of small streams in Costa Rica and the San Juan basin in Nicaragua. Though this species appears not to have penetrated the Nicaraguan lakes, but is very common in lacustrine habitats as well as in a wide range of riverine biotopes along the Pacific segment of its range (Hildebrand, 1926).
Comments: This species was imported into the United States in 1964, under the erroneous name Cichlasoma friedrichsthali. Recent articles purporting to deal with that species (Olson and Gianladis, 1970; Robinson, 1975) are actually about P. motaguensis.
Parachromis friedrichsthali (Heckel 1840)
Synonyms: Cichlasoma multifasciatum Regan 1905
Range: Southern México from just east of the Rio Coatzacoalcos into the Yucatan peninsula, the Atlantic slope of Guatemala and Belize. According to Miller (l966), the range of this species extends southward to Costa Rica. In view of the long standing confusion between this species and Parachromis motaguensis in the literature it seems prudent to admit that the southerly range limits of P. friedrichsthali have yet to be determined.
Habitat: Occurs over a wide range of habitat types throughout its range. Often found in association with waterlogged brush or tree trunks.
Comments: This species was originally imported into Germany from southern México in 1914. It was not bred and subsequently was lost to the hobby. It was first imported into the United in States in 1974, and spawned for the first time in captivity at Steinhart Aquarium in l978. The name P. friedrichsthali has been erroneously applied to P. motaguensis (vida supra) and to Cichlasoma atromaculatum Regan 1912 (Goldstein, 1973; Mayland, 1978), a species whose range extends from the Pacific slope of Ecuador northward into Panama.
Parachromis loisellei Bussing 1989
Adult size: Males to 30.0 cm SL., females to 20.0 cm SL.
Range: Is known from Suitable lowland habitats of the Atlantic versant from the Rio negro in Eastern Honduras (martin, 1972) as far south as the coastal drainages of Laguna de Chiriqui in western Panama (Loffin 1965). On the Pacific slope it is found in the Rio Tamarindo drainage (Villa, 1982) in Nicaragua.
Habitat: The sluggish waters of streams, backwaters and swamps.
Comments: Parachromis loisellei posseses considerable intraespecific meristic variation which overlaps the parameters of material of P. friedrichsthalii from the Petén, Guatemala. Nevertheless, the courting and and parental coloration of the Belizian and Petén populations is strinkingly and consistenly different from that of the form inhabiting Costa Rica.
- Astorqui, Ignacio. 1971. "Peces de la cuenca de los grandes lagos de Nicaragua". Revista de Biologia Tropical. 19(1,2): 7-57 (crc02792)
- Bleicke, C. 1971. "The behavior of a Central American cichlid fish, Cichlasoma managuense, and the functions of its color patterns: A laboratory and field study". Unpublished M.A. thesis, University of California, Berkeley (crc07460)
- Bussing, William. 1967. "New species and new records of Costa Rican freshwater fishes with a tentative list of species". Revista de Biologia Tropical. v. 14(n. 2), pp. 205-249 (crc06104)
- Davies, J. K & K.R. McKaye. 1978. "Cichlasoma dovii (Gunther l864)". Cichlid Index (American Cichlid Association). v. 3(n. 9), pp. 1-2 (crc07461)
- Davison, C. 1973. "The Cuban Cichlid". Buntbarsche Bulletin. (n. 34), pp. 9-10 (crc07462)
- Frank S. 1971. "Pictorial Encyclopaedia of Fishes". Littlehampton Book Services Ltd. pp. 1-560 (crc07465)
- Goldstein, Robert J.. 1973. "Cichlids of the world". TFH Publications. 382 p. (crc01754)
- Hildebrand, Samuel Frederick. 1925. "Fishes of the Republic of El Salvador, Central America". Bulletin of the United States Bureau of Fisheries. pp. 237-287 (crc01157)
- Hubbs, Carl Leavitt. 1935. "Fresh-water fishes collected in British Honduras and Guatemala". Miscellaneous Publications, Museum of Zoology, University of Michigan. (n. 28); pp. 13-15 (crc00252)
- Hubbs, Carl Leavitt. 1920. "A note on the synonymy of the cichlid fish of Cuba and Barbadoes, Cichlasoma tetracanthus". Occasional Papers of the Museum of Zoology, University of Michigan. (n. 90), pp. 1-8 (crc03549)
- Klee, Albert J.. 1971. "In quest of the Mayans. V". The Aquarium (Philadelphia). v. 4(n. 6), pp. 6-7 (crc07467)
- Loiselle, Paul V. 1980. "Labidochromis, The Dwarf Mbuna". The Cichlid Room Companion (crc02084)
- Loiselle, Paul V. 1980. "The Cichlasoma labiatum species complex". Freshwater and Marine Aquarium (FAMA). v. 3(n. 4), (crc07468)
- Mayland, Hans J. 1978. "Große Aquarienpraxis Teil III - Cichliden und Fischzucht". Landbuch Verlag, Hannover. pp. 1-461 (crc06470)
- McKaye, Kenneth R.. 1977. "Competition for breeding sites between the cichlid fishes of Lake Jiloa, Nicaragua". Ecology. v. 58(n. 2), pp. 291–302 (crc05338) (Kurzfassung)
- Meral, G. H. 1973. "The adaptive significance of territoriality in New World Cichlidae". Unpublished Ph.D. thesis, University of Califomia, Berkeley (crc07466)
- Miller, Robert Rush. 1976. "Geographical Distribution of Central American Freshwater Fishes". Investigations of the ichthyofauna of Nicaraguan Lakes. pp. 125-156 (crc06524)
- Miller, Robert Rush. 1966. "Geographical distribution of Central American freshwater fishes". Copeia. v. 1966 (n. 4); pp. 773-802 (crc01105)
- Mortensen, James. 1978. "Keeping big, nasty cichlids". Freshwater and Marine Aquarium (FAMA). v. 1(n. 4), pp. 14-17 (crc07464)
- Noms, R. E. 1971. "In quest of the Mayans. Sequel I". The Aquarium (Philadelphia). v. 4(n. 6), pp. 38-44 (crc07469)
- Olson, Richard & Gene Gianladis. 1970. "The Friedrichstahli's Cichlid". Buntbarsche Bulletin. (n. 23), pp. 12-15 (crc02417)
- Regan, Charles Tate. 1906. "Pisces". Biologia Centrali-Americana. pp. 17-31 (cichlidae) (crc00277)
- Regan, Charles Tate. 1905. "A revision of the fishes of the American cichlid genus Cichlosoma and of the allied genera". Annals and Magazine of Natural History. (Ser. 7) vol. 16; pp 60-77; 225-243; 316-340; 433-445 (crc00042)
- Robinson, Peter E. 1975. "Maintaining and spawning Cichlasoma friedrichsthali". Buntbarsche Bulletin. (n. 48), pp. 9-11 (crc07463)
- Sevilla, M. L. 1977. "Fauna acuática". Recursos naturales de la cuenca del Papaloapan. Instituto Mexicano de Recursos Naturales Renovables, México, D.F. pp. 437-454 (crc07470) (Kurzfassung)
- Sterba, Günther. 1966. "Freshwater fishes of the world". TFH Publications. 877 p (crc01877)
- Tee-Van, J.. 1935. "Cichlid fishes in the West Indies with especial reference to Haiti, including the description of a new species of Cichlasoma". Zoologica. pp. 281-300 (crc00263)
© Copyright 1998 Paul V Loiselle, all rights reserved
Loiselle, Paul V. (Mai 21, 1998). "Giant Predatory Cichlids, THE TRUE GUAPOTES". Cichlid Room Companion. Abgerufen am Juli 21, 2019, von: https://www.cichlidae.com/article.php?id=92&lang=de.