(This article was originally published in Cichlid News Magazine; october 1996; Aquatic Promotions Vol. 5 No. 4. pp. 65-70.).
Herichthys labridens female guarding her spawn, placed under a water lilie leaf (ninphaea sp.) in Medialuna spring, Pánuco system. Photo by Juan Miguel Artigas Azas.
Herichthys labridens is a Cichlid that certainly calls attention, it's beautiful breeding colors make it one of the most beautiful Central American Cichlids, and, however, it is also a Cichlid of which few things are known, being too much to know. Observations here written correspond to my own, carried out over several years, in which I have spent countless hours submerged in the waters of its habitat. I have also had the experience of captive maintenance and breeding of this species in my home aquariums.
Herichthys labridens was initially introduced to science when professor Alfredo Dugès of the University of Guanajuato, an avid explorer and collector, sent the specimens collected in the Rioverde valley in the center part of the Mexican state of San Luis Potosí (100°52'W.LON, 21°52'N.LAT) to the French Ichthyologist Jaques Pellegrin, who recognized the species as new. Pellegrin named the fish Heros labridens, specific name referring from the latin terms labrun meaning upper lip and dens meaning tooth, indicating this fish characteristic. The formal scientific description was published in "Description de cichlidés, nouveaux de la collection du Museúm", published in 1903 in the "Bulletin of the Natural History Museum in Paris" (Pellegrin, 1903), types of the species were deposited in the museum's collection.
In spite of the fact the "mojarra caracolera" was initially placed in the genus Heros by Pellegrin, a year after it's description, Herichthys labridens was re-described by the same Pellegrin (Pellegrin 1904), this time placing it in the Cichlasoma genus and accompanying illustrations of dentition and syntype. Regan reestablished the Cichlid, synonimized in 1904 with Herichthys bartoni by Meek, as a full species in 1905, as part of his Parapetenia section. The section was raised to generic status by Jordan, Evermann and Clark in 1930, this opinion is however, not accepted to our days, Parapetenia Regan 1905 being a junior synonym of Nandopsis Gill 1862. Therefore labridens remained in the Cichlasoma genus until Sven Kullander restricted it in 1983 (Kullander 1983, 1986), to some species related with the type species, Cichlasoma bimaculatum. The same Kullander in 1996 (Kullander 1996) published a diagnosis for Herichthys, where, based on some basic patterns of coloration, included labridens.
There has always been confusion relating the identity of the "Mojarra caracolera". Type locality established for the species was "Huasteca Potosina", which refers to a very large area, where several related forms inhabit, Guanajuato was as well given as a type locality, this last however most likely a mistake, originated by Professor Duges provenience. Posterior scientific papers on the species later than the description use fish from several locations and consider them all as Cihlasoma labridens", like that of Miller and Taylor (Miller & Taylor, 1983), where labridens variants are considered geographical forms and their differences stated. Another possibility not yet studied fully is that those forms could be species of the same group. In this respect Dr. Robert Rush Miller (pers. comm.) emeritus professor of the University of Michigan and one of the foremost authorities on Mexican freshwater fish, will describe the "tamul" labridens, an endemic labridens form from the Rio Gallinas, as a separate species.
The reason that leads me to presume that the Rioverde valley labridens is the fish originally meant as 'Cichlasoma' labridens, without having examined the museum types myself, stems from the fact that professor Alfredo Dugès carried out his collection in the Rioverde valley (Pellegrin 1903), and sent the types of the sympatric Cichlasoma bartoni to Bean (Bean, 1891) for his description, with specimens from the same collection. To this fact we have to add the original description of Herichthys labridens, which indicates the presence of a massive pharyngeal mollar shaped teeth, especially designed to crush mollusks, the favorite diet of Herichthys labridens in the Rioverde valley springs (Miller 1983), unique among the Herichthys labridens complex
|A view of Medialuna spring, Pánuco system, San Luis Potosí, México. Photo by Juan Miguel Artigas Azas.|
The "mojarra caracolera" has its habitat in the basin of Santa María and Verde rivers, west from the mouth of the Pánuco river in the gulf of México, in the Mexican state of San Luis Potosí. There are two geographic forms of this fish; one inhabiting the springs of the Rioverde valley and the second the rivers of reference. Both forms differ strongly from each other externally in their morphology and in their digestive apparatus (Miller & Taylor, 1983). The riverine form posses a more elongated body and a slightly rounded head, in contrast to the almost straight forehead and produced snout of the spring from, with eyes farther back, adapted for feeding in the soft substrate of the springs.
In the Rioverde valley, the "mojarra caracolera" can be found in springs scattered through the arid surface of the valley, some of them being: "La media luna", "los anteojitos", "manga larga", "los peroles", "las tablas", "laguna de San Bartolo" and "el Aguaje". Separated by distances up to sixty kilometers from each other.
The spring form of the fish has a reduced population, just a few can be found in each of the springs, where they live together with the endemic Herichthys bartoni, who outnumbers labridens by much. Another fish species sharing the habitat are: family goodeidae; Ateniobious toweri, Ictaluridae; Ictalurus mexicanus, Characinidae; Astyanax fasciatus, Cyprinodontidae; Cualac Tesselatus, Cyprinidae; Dionda mandibularis and Dionda dichroma and Poecilidae; Poecilia mexicana. The exotic species are also plentiful, although fortunately they are not present in all of the springs. Those are from the family Cichlidae; Herichthys carpintis, representing a menace to the population of the "Mojarra caracolera" in the Media Luna spring, as it hybridizes with Herichthys labridens and preys on the young as well. Sarotherodon aureus; the most widely distributed in the springs. The family Poecilidae also has exotic representation; Poecilia latipunctata; threatened in its habitat in the Tamesí river and plentiful in the Medialuna spring, and Gambusia panuco.
|Medialuna spring, Pánuco river system, San Luis Potosí, México. Photo by Juan Miguel Artigas Azas.|
In the verde and Santa María rivers Herichthys labridens is a plentiful species. It shares its habitat with Ictalurus mexicanus, Astyanax fasciatus, Poecilia mexicana and Gambusia panuco. The exotics. also present, are; Herichthys carpintis (Which naturally inhabits the lower parts of the Pánuco river), Sarotherodon aureus and Micropterus salmoides, a real threat for Herichthys labridens. Those species, nevertheless, are absent in Santa María river, with the probable exception of Sarotherodon aureus, present in some tracks of the river.
The springs show a bottom substrate covered by detritus layers and in some few cases mud (El aguaje, Las tablas). Immersed wood is also found in some of the springs (Los peroles, manga larga). Aquatic vegetation is also present, the most distributed are water lilies of the ninphaea genus, although some other types can be also be observed (La Media luna, El aguaje).
Water conditions in the springs and those of the river differ significantly. Springs are characterized by clear water with a constant temperature, from 26° to 32° Celsius degrees depending on the individual spring. Water chemistry gives lectures of high hardness, 50 German degrees or more. pH over 7.5. Verde river water has much less transparency than that of the springs, with variable temperatures depending of the time on the year. With an estimated temperature range from 20° to 28° Celsius. Water hardness is significantly less in the river although pH shows similar lectures.
Herichthys labridens juvenile in normal coloration. Medialuna spring. Photo by Juan Miguel Artigas Azas.
Herichthys labridens juvenile looking for snails in the soft bottom of Medialuna spring, Pánuco, México. Photo by Juan Miguel Artigas Azas.
Herichthys labridens juvenile in "hunting" coloration, Medialuna spring, Pánuco, México. Photo by Juan Miguel Artigas Azas.
Herichthys labridens female stirring the detritus to feed the fry in Medialuna spring, Pánuco, México. Photo by Juan Miguel Artigas Azas.
Herichthys bartoni breeding pair caring for their fry in Medialuna spring, Pánuco, México. Photo by Juan Miguel Artigas Azas.
Herichthys labridens from the springs is one of the most attractive cichlids there is. Its variable coloration and its interesting habits make this cichlid a real jewel. Normal coloration is golden yellow with five or six black blotches placed in a longitudinal row in the posterior part of the flanks. The head shows a blue coloration and over most of the body and fins a blue dotted pattern is present. Variability of the coloration has even driven to suggest (Staeck & Seegers, 1984) the existence of an additional species in the springs, which is not the case.
The mojarra caracolera spends its time close to the sandy or detritus bottom of the springs looking for its favorite food; snails. During hunting time coloration darkens to an almost velvety black, sometimes with some blue dots scattered on the body. The cichlid swims close to the bottom of the shallow areas of springs or channels in a lonely way, or joined by younger conspecific individuals. It stops once in a while to examine a small area. Then, with its chest and pectoral fins, wags the detritus until some snails are uncovered, those are taken and crushed with its powerful branchial musculature, easily observed from above. Once the snails are taken, the accompanying detritus is expelled through the gills, and the snails then crushed, with the shells subsequently expelled by the mouth. While hunting the younger individuals of Herichthys labridens follow the adults to take advantage of smaller snails or unwanted prey, those younger are usually ignored by the adults.
The situation for the riverine Herichthys labridens counterparts is quite different. They move in small groups of individuals of several ages in the faster flowing parts of the rivers, looking continuously among the boulders for small invertebrates or crustaceans, which ingest with a quick bite.
Coloration of the riverine Herichthys labridens is similar to that of their spring counterparts, although it is less variable and the dark feeding phase is not present. Males of "Mojarra Caracolera" reach a size of around 20 centimeters, while females grow to a slightly smaller length, around 18 centimeters.
Reproduction of the "Mojarra caracolera" takes place during the whole year in the springs form, given the constant nature of the conditions found in that habitat. However, a bigger activity is found from January to June, when due to the dry season water temperature increase slightly.
Pairs of Herichthys labridens are formed with males with a minimum length of 15 centimeters, and females no smaller than 12. They form with anticipation of the establishment of a territory, which can take several days after mating. When this happens, several potential spawning places should have already been examined. Once a site is chosen, in my observations generally the lower part of a water lillie leave (ninphaea) or some small calcareous stone (scarce in the springs) located in an isolated area. The pair proceeds to its cleaning followed by the spawning act, depositing several hundred yellowish-orange ovoid eggs, with an approximate size of two millimeters in its mayor axis. The adhesive eggs are placed with some separation between them, generally over a vertical surface, which I presume is done to avoid the accumulation of detritus over them.
Breeding coloration exhibited by this fish is maybe the most beautiful found in a Central American cichlid, only rivaled by the sympatrical Herichthys bartoni. The body takes a bicolor coloration, with a striking contrast of a canary yellow in body and fins, and well marked black areas in the lower half of the head and belly, as well as in posterior part of the flanks to the caudal peduncle. Caudal and anal fins maintain the bright yellow coloration. The tips of the two or three anterior dorsal spines also turn black. In fact, a sight worth to behold!
Eggs are carefully taken care of by the female, who stays alongside avoiding any particle to settle on them. The male stays in the perimeter of the territory, chasing away intruders, although he is not willing to face any big danger, like for example a human approaching. Given the case, the male gets away from the territory, and only the female stays. The eggs take a couple of days to hatch and the wrigglers are then placed in a pre dug pit on the base of the spawning site, for their protection. In this place they stay for five more days until the hanging yolk sacks have been consumed, providing their first meal.
Once the fry starts swimming they are carried by the parents throughout the habitat, and they never come back to the spawning place. The fry are guided by spasmodic movements of closing and opening of their parents fins, and shaking of the body, movements that are followed closely by the fry. The male takes the general direction, while the female keeps close to the babies. In this phase the male feels more attached to the fry and keeps closer to them. A good amount of time and energy has been already invested in the batch of fry. When dangers become present, he normally faces them. Even the presence of human beings is tolerated most times, without running away.
Feeding of the fry is something fascinating. The parents, in alternated turns dig part of their chest and belly into the soft organic detritus in the springs or river bottom. Wagging it to cause small detritus clouds, over which the small fry immediately forage on the uncovered edibles. This behavior continues without stopping.
When a menace approaches, immediately the pair proceeds to guide their fry to the protective cover offered by the water lilies (ninphaea sp.), under whose leaves they take shelter till the danger goes away.
The fry finally abandons their parents when they have reached a size that allows them to survive by themselves, around two centimeters in length. It is at this moment that they seek for shelter around the dense underwater cover offered by the water Lillie beds. When they are a little bigger they join the adults in the hunt for snails, like apprentices. The pair, once their fry gets dispersed, splits maybe permanently, getting back to their normal behavior.
The potential natural pedrators of Herichthys labridens are several, although none in an specialized way. We could talk about fish eating birds, like loons, herons and king fishers, plentiful in the habitat, although perhaps the favorite preys of those are the smaller Astyanax fasciatus. Other potential pedrators are the water turtles and snakes, also plentiful in the habitat. Humans do not consider the "Mojarra caracolera" a desirable meal, given the totality of the catch and farming of the native people focus on the introduced Sarotherodon aureus. Herichthys labridens doesn't seem to suffer a strong pressure from the pedrators.
Captive maintenance considerations
The "mojarra caracolera" can be kept successfully in captivity. Tanks of a suitable size and good water quality being perhaps the main requirements. The high aggressiveness of this cichlid lead us to aquariums with a minimum length of 1.2 meters (4 feet). At least I wouldn't suggest anything smaller. Aquariums longer than two meters (6'8") allow us to observe a more natural behavior of the species. If wild specimens are obtained, quarantine should be considered. An existent disease in the natural habitat in the Pánuco river basin and generally just rarely manifest in wild specimens, under the stress conditions of an aquarium will surely do. Once it does, it will be hard to eradicate. So it is always necessary to quarantine. The disease manifest itself by a pop out of scales in one area of the flanks, growing concentrically and causing an ulcer in the skin, which spreads until it kills the fish. At the beginning the fish seems not to notice the ulcer, but in a few days will stop feeding, this is a point of no return. I have noted that the disease can be prevented or even treated with the help of the parasiticidal "Clout" tm.
Feeding of Herichthys labridens is not a problem, it takes whatever is offered, although it is always better to avoid foods with grease or a high contain of terrestrial animal protein, which can originate digestive disorders.
Water chemistry plays a secondary paper as long as extremes are avoided. However, the quality of the water is of first importance. Even at the slightest loss of water quality the fish losses appetite and become susceptible to sickness. Because of this it is important to keep the aquarium well circulated with good water quality. Frequent water changes are a big help in this respect.
I want to conclude this article with a consideration relative to the conservation of this species. The springs in the desert zones suffer the pressure of the growing demand of water for human use. This has led to the disappearing of many of the springs with the consequent extinction of inhabiting species, a fact not only deplorable by itself, but that does not resolve any problem. It is just a mater of time for the underground water reserves to get unable to sustain the amount of extracted water and its extraction forced to be rationalized or even stopped for a period of time, with the consequent bankruptcy of the human activities. Underground reserves will likely reestablish in time, but no so the disappeared fauna of the springs. Another danger is the introduction of exotic species, like has happened in the popular Media Luna spring. Non native species, will just put stress on native ones and endanger them, leading them even to disappear. This is also a big problem, so we have to make consciousness of not introducing species that do not belong to a habitat, but to dispose of them in another ways. Beyond the ecological richness and beauty that the desert species represent, they also let us understand evolution and geological processes. It is for this reason that someday we'll have to get conscious of the conservation of desert water bodies.
The relatively reduced number of individuals of the "Mojarra caracolera" in the Rioverde valley springs make them a susceptible target to disappear in any given moment because of the alteration of its natural habitat. This is something we should get conscious of.
Herichthys labridens female guarding her fry in Medialuna spring, Pánuco, México. Photo by Juan Miguel Artigas Azas.
- Bean, T.H., 1891, "Notes on fishes collected in México", Procedures U.S. Natural Museum.
- Kullander, Sven, 1983. "A revision of the South American Cichlid Genus Cichlasoma (Teleostei: Cichlidae)", Stockholm.
- Kullander, Sven, 1986, "Cichlid Fishes of the Amazon river drainage in Perú", Swedish Museum of Natural History, Stockholm.
- Kullander, Sven; 1996; "Heroina inonycterina, a new genus and species of cichlid fish from Western Amazonia, with comments on Cichlasomine systematics"; Ichthyological Exploration of Freshwaters,Vol. 7 No. 2, pp.149-172, 13 figs, 5 tabs, September 1996. Verlag Dr. Friedrisch Pfeil, München, FRG - ISSN 0936-9902.
- Miller, R.R. and J.N. Taylor, 1983 "Cichlid fishes (Genus Cichlasoma) of the Rio Pánuco Basin, eastern México, with description of a new species", Occasional papers of the Museum of Natural History, the University of Kansas 104; pp 1-24.
- Pellegrin, Jaques, 1903, "Description de cichlidés, nouveaux de la collection du Museúm", Bull. Mus. Hist. Nat., Paris. 9:120-125.
- Regan, C. Tate, 1905. "A revision of the fishes of the American Cichild Genus Cichlosoma and of the Allied Genera." Ann. Mag. Nat. Hist. Ser 7(16): 60-77, 225-243, 432-445.
- Staeck W. and Seegers L., 1984, "Die Fishe der Laguna Media Luna und der Laguna Los Anteojitos, río Verde, Mexiko. 3 Die Cichliden", Datz 37:204-209.
- Rivera Anaya, José, 1981, "Rioverde, la ciudad y el valle", Ayuntamiento de Rio Verde, S.L.P. pp:38-50.