|The waterfalls at Tamasopo, a beautiful landscape of the Gallinas river, which runs inside the Eastern Mother Ridge in México. Photo by Juan Miguel Artigas Azas.|
Endemic from the Rio Pánuco basin in the Atlantic slope of northeastern México is found a beautiful assemblage of aggressive Cichlid species now classified in the Herichthys genus by Sven Kullander (Kullander, 1996).
The Pánuco river system, second largest Mexican Atlantic drainage and one of the most beautiful and extended found in the country, has been pouring it's entire flow for thousands of years into the Gulf of México, witnessing in the meantime the lifting within its course of the Mexican Eastern Mother ridge, a long chain of high mountains running parallel to the gulf coast from within parallels 20° to 26°.
The geological activity in the zone over the centuries changed the whole physiognomy of the area and of the older river system, building geographical accidents that are nowadays source of astonishing beauty, as well as effective biological barriers for the aquatic fauna inhabiting the Pánuco. Over the pass of thousands of years fish populations coping with the changed habitats took somewhat divergent evolutionary paths, inducing in many cases speciation from previous species.
Cichlid fishes have not escaped this events, and the Pánuco river system show us today one "Herichthys" species of uncertain ascendance and restricted range, Herichthys bartoni from the Rioverde valley in the western part of the basin, which keeps more resemblage to the western basin Herichthys beani than to any of the Rio Pánuco Cichlids (No surprisingly given the fact that in some time this part of the basin must have been flowing west as it is testified by other western fish forms in the area). and two other species groups, the first associated with Herichthys carpintis and the second with Herichthys labridens, specific that translates from Latin as "teeth on the upper lips", and which is the subject of this writing.
Herichthys aff. labridens "blue" in the aquarium, this specimen was collected in the Tampaon river, a low land tributaire of the Pánuco. Photo by Juan Miguel Artigas Azas.
Herichthys steindachneri, an endemic piscivorous of the Gallinas river, aquarium specimen collected in Tamasopo river. Photo by Juan Miguel Artigas Azas.
|A female Herichthys pantostictus in breeding coloration. The species is apparently endemic of the muddy laggons around the Pánuco mouth. This specimen was collected in Laguna de la Puerta, near the type locality in Laguna del Chairel, just north of the city of Tampico. Photo by Juan Miguel Artigas Azas.|
|A breeding pair of Herichthys aff.labridens "Tamul", also kwon by aquarists as the "Tamasopo labridens", this picture was taken in the Tamasopo river. Photo by Juan Miguel Artigas Azas.|
|A juvenile Herichthys labridens in normal coloration, this picture was taken in Medialuna spring, a thermal spring located in the Rioverde valley just south from the city of Rioverde. Photo by Juan Miguel Artigas Azas.|
What did the ancient form of Herichthys labridens looked like?, I could surely not to tell, but the fact is that twenty century bestow us with what at present time are recognized by ichthyologists as three species of the group; Herichthys labridens, Herichthys steindachneri and Herichthys pantostictus, something that tends for change in the future, as more species will be added (Robert Miller, personal communication). It is also a fact that this Cichlid assemblage has lead to confusion about the identification of the individual species as well as their provenience.
Herichthys labridens was first described as Heros labridens by the French Ichthyologist Pellegrin in 1903 (Pelegrin 1903). The specific name labridens comes from the latin terms labrun meaning upper lip and dens meaning tooth, expresing this fish characteristic. Description was based on specimens collected by professor Alfredo Dugès of the Mexican University of Guanajuato in the Rioverde vally near the city of the same name (100°52'W.LON, 21°52'N.LAT). Pellegrin mentions in his description of Herichthys labridens that types of Herichthys bartoni, were collected sympatrically. Type Locality was however stated by professor Duges as "Huasteca Potosina", the name as it is known a large part of the Rio Pánuco basin (Outside of the Rio Verde valley area). Pellegrin also added Guanajuato to Huasteca Potosina as type localities, something which is clearly a mistake (there are no Cichlid fishes native to Guanajuato state) caused perhaps because of professor Duges provenience. The original description of Herichthys labridens indicates massive pharyngeal mollar shaped teeth, especially designed to crush molluscs, the favourite diet of Herichthys labridens in the Rioverde valley springs (Miller 1983), and unique among the Herichthys labridens complex.
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. The Cichlid, synonimized in 1904 with Herichthys bartoni by Meek, was reestablished as a full species by Regan in 1905, as part of his Parapetenia section. The section was raised to generic status by Jordan, Evermann and Clark in 1930, this placing however, is not accepted to our days, Parapetenia Regan 1905 being a junior synonym of Nandopsis Gill 1862.
Kullander revision of the Cichlasoma genus in 1983 (Kullander 1983) left Herichthys labridens genus-less for a while, but recently the same Kullander (Kullander 1996) has made a new diagnosis for Herichthys , where he included the whole labridens complex as well as Herichthys bartoni together with the "guapotas" of the Herichthys cyanoguttatus species group. Another more detailed diagnosis of Herichthys with clear limits established is expected soon by Dr. Robert Rush Miller and Steven Norris.
The last scientific paper that deals at detail on the now Herichthys labridens species complex that I am aware of is that of Jeffrey N. Taylor and Robert Rush Miller (Taylor & Miller 1983) published by the University of Kansas in 1983 and titled "Cichlid fishes (Genus Cichlasoma) of the Rio Pánuco basin, Eastern México, with description of a new species", a very detailed and comprehensive document, where, together with the description of Herichthys pantostictus, there are re-descriptions of Herichthys steindachneri and Herichthys labridens, this late based in a pool of different labridens forms collected in over fifty locations all abroad the Pánuco system. Herichthys labridens morphs from several locations are considered as one single species with geographical variations, due to their similitudes.
Dr. Robert Rush Miller of Michigan University has expressed to me, that he is working to soon recognize another labridens form, the one known as the Tamasopo "white" labridens or "Tamul" labridens, inhabiting the isolated Rio Gallinas in the mid-western part of the Pánuco system, as a new species.
The several forms of the labridens complex exhibit a common set of characteristic traits like: A scaleless red to dark purple area just behind the pectoral fins, color dependent of the form in question. A mouth; small and slightly facing downwards (sub-terminal), with the upper lip projecting beyond the lower, this last trait just lacking in Herichthys steindachneri from Rio Gallinas, understandably due to its piscivorous nature. Another feature is a delicate pattern of brown dots distributed all over the head. One behavioral trait is the common use, by parental fish, of the body and pectoral fins for stirring the substrate, with the purpose of uncovering small edible matter for the fry.
Is my opinion that the related group of species of Herichthys labridens, all inhabitants of the Pánuco river basin, exhibit enough unique characters to guarantee a formal study of the possible erection of a new genus for them.
The Rioverde Valley
Estimated twelve thousands years ago the valley of Rio Verde (99°30'-100°30'W.LON, 21°30'-22°49'N.LAT), was a large lake of around 20 meters deep (Nieto 1984). The valley is located in what it is today known as the middle zone of the Mexican state of San Luis Potosí, about 10,000 Km2 of semiarid land full of endemic flora and fauna, at 1,000 meters over sea level. Over the pass of the years either erosion or tectonic activity caused this lake to be drained to the Gulf of México by the Rio Verde, a Pánuco affluent, leaving behind a large swampy area where primitive man are know to have hunted for mammoths along the muddy shores. Over the years the swamp dried leaving behind small warm water springs all around the region, springs present to our days. Those springs and their associated lagoons are kept isolated from each other by the extremely permeable nature of the floor in the valley area. This environment holds what used to be the lake fauna, isolated now and evolving in their own paths to take advantage of the harsh environment.
Together with several fish species, two cichlids share the natural habitat endemic to those lagoons, Herichthys bartoni and Herichthys labridens, this last the so called yellow labridens. Of high head and stepped profile, Herichthys labridens, known locally as "Mojarra caracolera", makes its living by feeding on snails obtained sifting through the lagoons sand and detritus bottom. Snails are subsequently crushed without problem with it's well developed molariform teeth and strong jaw musculature. The fish, with a marked skill for changing colors according to it's mood, makes of feeding time an almost religious ceremony, changing it's normally yellowish coloration to a dark, sometimes velvety black pattern, where just blue sprinkles shine on its body flanks. These moments you may watch the individuals sifting laboriously through the organic detritus, looking for his favorite food, and they would even appreciate you if by accident or intention mess a portion of sediment with your presence, making easier their chores.
But this ability for changing colors just get to it's maximum expression when breeding comes to their lives, which due to the very stable environment of the springs takes place along the whole length of the year, only with a peak from December to March. Then a canary yellow and velvety black color pattern dress them, and this change makes the fish one of the most delightful sights of the Cichlid world.
Pairs look for a hidden solid surface to lay their eggs, something that would be an easy chore on the river, but not on this habitat, where stones are scarce and sometimes not located in the more protected areas, so many times the underpart of a water lilie leave take their place. Nevertheless, once a place is chosen and after being thoughtfully cleaned with the pair's strong mouths, hundreds of about three millimeters light orangish (In the springs) eggs are laid, fertilized and fanned for two days by the pair, when wrigglers hatch from them. At that time they are transported to a large pre-dug pit below the spawning place, where it takes them around five days more to be able to swim, while in the meantime they consume their ripe yolk sacks.
Pairs care for their fry in a ferocious way, water in the springs is clear and enemies many. Food is provided by the mother in the form of organic detritus or small organisms disturbed by wagging her lower body into the substratum, thus causing a debris cloud upon which the fry greedily forage. Time pass for the fry in this manner as they grow, interrupted only by outbreaks of potential danger, which approaches in the form of predators or a curious observer. When dangerous moments come, the male either face the intruder or if it happens to be too big, graciously flee away. The female stays and call her fry with spasmodic movements of opening and closing her fins, guiding them to hide under the leaves of water lilies ninphaea, until danger is gone. Shelter is found at dusk in the same manner.
It is not however until the fry reaches two to two and a half centimeters in length aproximately that those remaining finally decide to leave their parents. At this point they keep close to the overhanging vegetation at the shores of the channels that supply them with shelter. Youngs can also be commonly seen around feeding adults where they learn the substratum sifting skills, and in the process benefit from uncovered small snails or inverts that adults won't consider for them, large fish don't seem to bother with the cloud of young pupils around them. Guides often just ignore the following youngers provided they behave and do not intend to steal their chosen food.
Herichthys labridens and Herichthys bartoni do carry a respectful community sharing of their habitat, ignoring each other most of the time, this perhaps due to the fact that no direct feeding competition is present among them. H. bartoni, with its conical teeth feeds mostly upon algae and decaying organic matter. Ratio among both species is however overwhelmingly superior to Herichthys bartoni, and as a matter of fact the Herichthys labridens from the springs, although present in all of them could be considered scarce.
Medialuna, one of the largest of the Rioverde valley springs presents additional problems to the fish. Man made irrigation channels called "asequias", dug historically from this spring since the seventeen century, have managed to change the physiognomy of the semi-arid land, giving place to a rich agriculture activity. A large concrete channel that feeds a net of smaller ones was built in 1977 to take advantage of the large flow from the spring, the new channel crosses now the Rio Verde, where a different aquatic fauna thrives. It happens that species from the Rio Verde managed to get into the channel and the opposite, Herichthys carpintis has colonized the artificial course and got presence in Medialuna itself. Although H. carpintis does not do very well on the place, it did however hybridize with Herichthyslabridens to a certain extent, although it seems however that hybridization has decreased lately. But now H. carpintis presents an additional threat to natural Cichlids, as in the absence of more generalized feeding, youngs prey upon Herichthys labridens and H. bartoni fry.
Sarotherodon species have also been introduced to the springs as a food source for country people, it has been thought they could pose a threat to natural Cichlids, but the fact is that with the pass of the years I have observed their inability to adapt to the environment, where they look thin and prone to diseases. I have even witnessed their numbers to decrease, with their complete extinction from "Los anteojitos". spring, where they were initially introduced. More recently and with unkown future results the catfish Ictalurus furcatus has been introduced as well to Media luna.
Herichthys labridens has a riverine form inhabiting the Rio Verde, it is very similar to the one found in the springs, differing mainly from them in body morphology and gut length, issuing a more rounded profile and less heightened head and eye, but showing even the same breeding coloration. Intestine on the riverine form is longer than that of the springs H. labridens. Denoting that an amount of vegetal matter is consumed. Environment in Rio Verde is however very different from that found in the springs. While in the springs the labridens are used to very slow flowing water with stable temperatures from around 28°C to 32°C ,and a great visibility, the river brings moderately fast flowing water as the H. labridens preferred habitat. Significant temperature and water level fluctuations are normal and the former can go from about 18°C to 28°C, visibility is rarely over two meters and food is more plentiful in a less specialization required manner.
Herichthys labridens in the river feeds on inverts they collect in a similar way as it's spring counterparts, but looking for them in moderately fast flowing waters among the boulders. The breeding season is limited to the period from March through June, stopping when strong rains bring much higher water levels with the corresponding drop in water temperatures, decrease in visibility and faster water flows.
For spawning sites, males of the riverine Herichthys labridens dig a cave about ten to fifteen centimeters wide and deep at the base of a rock, not in shortage in the area. The place they choose for spawning generally is located at a well oxygenated zone in a moderately flowing area of the river. Both male and female finish cave digging until they finally fit into. Then they clean a wall in preparation as a spawning site. The rest of the biological cycle of the river yellow labridens matches that of their springs counterparts.
The range in which the riverine Herichthys labridens can be found is located in the western part of the Pánuco system. The Verde and Santa María rivers, from an altitude of 1000 meters over sea level to the their merging point (99°14',21°38'N.LAT.), and down the resulting Tampaón river until a geographical barrier in the form of an underground passage through the ridge it seems to prevent their access downwards.
The Gallinas river
In the way down the Tampaón river an astonishing geographical accident calls attention in the middle of the Huasteca tropical forest, far from populated areas. It is the hundred and two meters high Tamul waterfall (99°13'W.LON.,21°42'N.LAT.). This cascade pours the entire flow of one of the most beautiful rivers of the Pánuco system, the Gallinas (Chickens) river into Rio Tampaón. The geographical accident has provided an effective way of isolation of a unique fish fauna in Gallinas river, several endemic fish species are known from the river.
Two labridens forms live in the river in a peculiar and close relationship, one is Herichthys steindachneri Jordan & Snyder 1899, with a type locality stated at Rio Gallinas at the town of Rascón (99°16'W.LON.,21°54'N.LAT.), the other is the so called "tamul" labridens, so far undescribed as a species. Both cichlids should be descendent of a common fish. How speciation took place without isolation, is yet a mystery. My bet is that the lack of the piscivorous Gobiomorus dormitor goby in the Gallinas river created the niche for a piscivorous cichlid morph to develope from the more generalized Herichthys aff. labridens "Tamul". Something that could serve as precedence to this opinion are the studies about Herichthys minkleyi, a polymorphic endemic of the swamps of "Cuatro Cienegas" in the northern Mexican state of Coauhila. In Cuatro Cienegas three morphs of the cichlid inhabit together, the three taking advantage of different specialized food sources their environment can provide, the three different in the way their morphology adapted to their feeding habits, the three of them inter-breeding with each other and producing mixed fry of the parents mophs.
A similar situation could be the case with the two Gallinas river labridens. Herichthys steindachneri, a large and slender cichlid with a long prognathous snout and conical teeth, possessing large canines in the outer part of their lips, seems specially designed for fish predation, something it surely does, the characinid Astyanax mexicanus being frequently chased and eaten by the fish, an event that could be replicated easily in the aquarium environment. On the other hand, Herichthys aff. labridens "tamul", a little smaller in comparison, holds molariform teeth and a rounded profile, and makes its living eating invertebrates in a similar fashion the Rio Verde labridens does, sifting among the sandy and detritus river substratum. Ratio among the two cichlids is very much on the side of the "Tamul" labridens, and if I adventure to say 100 to 1, I am sure I am not much off the true numbers.
Of cooler water than Rio Verde, with a temperature range that fluctuates during the year between about 16°C to 28°C, the Rio Gallinas is characterized by it's clear and well oxygenated waters (PH 7.6 GH 100° German), the beauty of the river contrasted for many years with the heavy pollution caused by two sugar mills installed in it's margin; "Agua buena" at the town of the same name and "Alianza popular" at the town of Tambaca, pollution that killed any large form of life in the river bed down those towns, a portion that could be estimated in fifty percent of the river, some joke around it would prey that if you wanted a free "Cuba libre", all you had to do is put a glass inside the river at the Tamul waterfalls, where the brown water and all the sugar canes inside make it look just like that.
Pollution has fortunately decreased now as treatment plants have been installed in the mills, but many years will pass until the complete river is reestablished with their old fauna. Given those facts, Herichthys steindachneri can so far just be found in Rio Agua Buena, from the waterfalls near Tamasopo down to the town of Tambaca, and in Rio Ojo Frio down to Rio Agua buena, where both rivers merge to form Gallinas river. The "Tamul" labridens exceeds that range just in the headwater of Tamasopo river above the waterfalls, something that suggest the labridens arrived first to Rio Gallinas and then Herichthys steindachneri evolved.
Pairs of both fishes form from December through June with a peak in march, period when they dig a cave at the base of a rock sufficiently large to hold them inside, spawn then takes place in a previously cleaned wall of the cave, in the same fashion than the riverine yellow labridens does, only eggs being yellowish instead of orange. Pairs of the "Tamul" labridens mate from a size of about ten centimeters for males and seven for females, contrasting with those of Herichthys steindachneri that just form pairs with females of at least fifteen centimeters and with males around twenty.
Breeding coloration of the two fishes also differ, the "Tamul" labridens holding the most attractive one with a black and white checkboard pattern, white on the forehead. Herichthys Steindachneri hardly experience any change in coloration, I theorize being larger doesn't need to show very much power. Hybrids of the two cichlids do exist, A pair of a male Herichthys steindachneri and a female "Tamul" labridens was photographed underwater by Ad Konings in march 1991, caring for their fry, this explains the occurrence of fish that look very much in between the two, but just found below the Tamasopo waterfalls where both fishes live together.
Adults males of Herichthys steindachneri are the largest cichlids on the Pánuco system, being in some cases over forty centimeters in total length in nature, although some "Tamul" labridens males in some exceptional cases could very well be over thirty, but averaging around twenty two.
The lower Pánuco
Down the Tampaón river and all abroad the lowland areas of the Pánuco rivers, including the Tamesí, which is the Pánuco northern branch, the Moctezuma and Tempoal, southern Pánuco arms, a different form of Herichthys labridens inhabits, which is commonly know as the blue labridens, it could be the oldest representative of the group due to his lowland large range, the largest distribution of all the Herichthys labridens forms, that extends even to some southern small rivers that do flow into the Gulf of México and don't merge the Pánuco river itself.
The fish, that posses molariform teeth, makes its living very much in the same way that the "Tamul" and riverine riverine Herichthys labridens do, preferring fast flowing waters with boulder beds for feeding. This fish, however, shows a significant difference in normal and breeding coloration to the other labridens morphs, with a blue pattern and a red edge on his dorsal and anal fins. The scaleless blotch behind the pectoral fins, common feature of all the Herichthys labridens forms, is blood red instead of the dark purple observed in all the others.
This fish, however, shows geographical variation in morphology and aspects of coloration, and there is even a morph isolated up Tio El Salto, a river flowing into Rio Tampaón, that shows a breeding pattern more like the one seen in the "Tamul" labridens, and lives together with an Herichthys morph also characteristic of that river.
The lowland lagoons
Isolated in coastal lagoons near the Pánuco mouth, Herichthys pantostictus lives in an habitat very different to those in which it's close relatives are found. Being described by Jeffrey N. Taylor and Robert Rush Miller in 1983 from specimens collected at the coastal lagoons "Laguna de la Puerta" and "Laguna del Chairel", this last type locality, both located around the city of Tampico, the Mexican largest port found in the Gulf coast. Herichthys pantostictus specific name comes from Greek meaning "spotted all over". Differs from other labridens in precisely having it's entire body covered with small brown spots, also observed in it's close relative the blue labridens, but in much lesser degree. Other differences are a shorted caudal peduncle (not surprising given the stagnant nature of its habitat) and longer basal length, longer dorsal and caudal fins, with anal spines predominantly numbering VI.
Lagoons where Herichthys pantostictus inhabits are murky with very low visibility of normally less than half a meter, bottoms are always muddy. I have observed that in lagoons with clear waters and sandy bottoms like "laguna de Altamira", the Cichlid can not be found, but just Herichthys carpintis, which normally inhabits sympatrically with H. pantostictus. Water in the lagoons vary in temperature from around 18°C to 28°C, and show some degree of salinity.
A steeped profile and molariform teeth suggest that the Cichlid feeding habits differ no much from other labridens, matching perhaps more closely to Herichthys labridens from the Rio Verde valley springs, which also resembles in overall shape, something not surprising given the similarity of bottoms they sift and the stagnant water state of their habitats.
Breeding coloration in Herichthys pantostictus follows the patterns of the labridens group, just this time being all black with a white forehead, breeding habits are difficult to know because of their murky habitat, but breeding time should go between April and June, at least this is the range of time when I have collected Cichlids with ripe gonads. The fish grow to over twenty five centimeters and has already been spawned in captivity.
An interesting note about Herichthys pantostictus is that two specimens of the Cichlid were collected in head waters of Rio Sabinas in the upper part of the Tamesí river together with blue labridens by R.M. Darnell in 1962. Whether they were Herichthys pantostictus or not we should have to wait to see some more collecting reports, I personally have not observed Herichthys pantostictus in Rio Tamesí or it's affluents, including Rio Sabinas, but the blue labridens which resembles it a big deal. Besides, both fish present molariform teeth and they should feed upon the same items, so I believe competition would not allow closely related Cichlids to co-habit and have the same feeding habits.
Of all the labridens morphs, in my own experience Herichthys pantostictus is the more aggressive one, and this says a lot considering the labridens group is one of very aggressive Cichlids, requiring tanks over four hundred liters and many companions to do fairly well until they grow or breed. They however do pretty good in tanks over five hundred liters, where they can be easily induced to breed in a community situation. This is achieved when they get the right size, provided they have the well oxygenated low organics water they are used to in the wild, which is required for their well being. On this matter of water quality I should mention I have observed labridens species tend to get sick if water conditions do not suit their needs, even for a short period of time.
Cichlids and fishes that do not naturally compete directly for the same food are ignored by labridens under aquarium conditions. This include Herichthys species of the cyanoguttatus group, some of which occur sympatrically with the Cichlid. Fish that don't easily fit their mouths are normally ignored outside breeding time, and even if they do fit their mouths are also normally ignored. Exception of this rule is of course Herichthys steindachneri, which would be happy to eat all the small fish you can provide it. This Cichlid, however, in my own experience also tends to be the least aggressive of the labridens group.
Herichthys labridens do stand low water temperatures as much as 18°C without any sign of distress. In this situation appetite diminish and considering they are rather slow growing fish, is not advisable if what you want is to watch them grown.
With this we may now have a picture of the Herichthys labridens complex. But nevertheless, if different morphs are considered or not as full species by people studying their relationships, the reality is that we, Cichlid lovers that enjoy the fact of watching and keeping different Cichlids, are gifted by nature with several labridens forms full of color, interesting behavior and great personality.
- Darnell, R. M., 1962, "Fishes of the Rio Tamesí and related coastal lagoons in east-central México", Publ. Inst. Mar. Sci. 8:299-365.
- Jeffrey N. Taylor and Robert Rush Miller, 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. 104:1-24.
- Nieto L.M., Velásquez , Rojas C. and Rivera , "Rioverde", 1984, Ayuntamiento de la ciudad de Rioverde.
- Pellegrin, , 1903, "Description de cichlidés, nouveaux de la collection du Muséum", Bull. Mus. Nat. Paris. 9:120-125.