Descripción original como Heros (Cichlasoma) labridens:
- Pellegrin, Jacques. 1903. "Description de Cichlidés nouveax de la collection du Muséum". Bulletin du Musée National d'Histoire Naturelle. pp. 120-125 (crc00260)
- Heros (Cichlasoma) labridens, Pellegrin, 1903, combinación original.
- Cichlasoma (Cichlasoma) labridens, Pellegrin, 1904, nueva combinación.
- Cichlosoma (Theraps) labridens, Regan, 1905, nueva combinación.
- Parapetenia labridens, Jordan et al, 1930, nueva combinación.
- Cichlasoma (Parapetenia) labridens, Taylor et al, 1983, nueva combinación.
- Herichthys labridens, Kullander, 1996, nueva combinación.
- Nosferatu labridens, De la Maza Benignos et al, 2014, nueva combinación.
- Hábitat: secondary rheophilus
- Alimentación: moluscívoros
- Morfología: medium sized cichlids
- Acuarismo: acuaristas intermedios
- Reproducción: substrate brooders
Etimología: labrum = lip (Latin) + dens = tooth (Latin); in reference to the easily visible tooth they hold in the upper lips, visible even in live specimens.
Tipos: Two syntypes collected by University of Guanajuato professor Alfredo Dugès in 1889 and deposited in the Museum of Natural History of Paris (1889-019 and 1889-020), which have a total length of 222 mm and 196 mm. respectively.
Diagnosis: From the original description: D. XVI,11; A. V-VI,8; P. 14; éc. 5 1/4/30/12-13; L. Lat. 18/8-10; éc. Joue 5-6.
Even though the original description do not clearly diagnosis the fish, something normal in descriptions of the time, it is mentioned that a “massive pharyngeal teeth, rounded and flat, with molars disposed so that it seems to indicate that it is an animal that can feed upon mollusks with strong shells” (Pellegrin, 1903). Pellegrin offers some diagrams of the teeth in a re-description of the species in a subsequent publication (Pellegrin, 1904).
Jeff N. Taylor and Robert Rush Miller (1983) offer a complete diagnosis where they distinguish Herichthys labridens from other species of the genus as "having a small or medium sized mouth, angled downwards in the anterior part, the upper jaw projecting over the lower one, well formed mollariform teeth in the lower pharyngeal mill plate. Long caudal peduncle, as least as long as it lesser depth. The sides of the head and the forehead sprinkle with small dots not extending to the body. A magenta blotch in the axils and a conspicuous bicolor pattern in specimens in breeding coloration".
It has to be noted that for this diagnosis several distinct species of the H. labridens group were used (considering them as geographical variants), although the above mentioned characters extend generally to the group of species. H. labridens nevertheless can be unmistakably diagnosed from other species in the H. labridens group by its breeding coloration; canary yellow with two velvety black areas, the first in the ventral part of the head down from a level below the eyes, that extends from the premaxila back to ray VIII in the dorsal fin, including the pectoral fins, and a second area that extends from the insertion of the anal fin to the base of the caudal fin, not including the anal fin, which remains yellow.
Tamaño: Herichthys labridens grows to a length of about 20 centimeters in the wild for males, females remain smaller to about 15 cm. In captivity, that size could be surpassed.
Dimorfismo sexual: There are not evident sexual differences between the sexes. Venting them shows a more pointed genital papillae in males and a shorter blunt cylindrical papillae in females.
Localidad tipo: Huasteca Potosina, Mexico.
Distribución: The lacustrine form inhabits the springs in the Rioverde valley in San Luis Potosí; La Media Luna, Los Anteojitos, Manga larga, Poza Azul, Los Peroles, Laguna del Cedral, Laguna de las Tablas, Laguna de San Bartolo, Puerta del Río and perhaps some more. A riverine form inhabits rivers Verde and Santa María up to a thousand meters over sea level. Both rivers are affluent of Rio Tampaón, Pánuco; San Luis Potosí [México].
Paises que habita: México (endemic).
Biótopo: Lacustrine: Well oxygenated clear water deep thermal springs in the Rioverde valley (temperature 25-32 Celsius). Aquatic vegetation is present in the form of water lilies (Nimphaea sp.) and Najas marina. Riverine: Sandy or rocky bottom rivers with strong currents (temperature 22-28 °C.). pH alkaline over 7.5 and water very hard.
Alimentación: Lacustrine: Snails (Taylor & Miller, 1983) and detritus. Riverine: crustaceans, seeds, plant material and insects (Diaz Pardo et all, 2002).
Reproducción: In the Rioverde valley Herichthys labridens reproduces during all throughout the year due to the constant environmental conditions of the springs in the valley. In the rivers Verde and Santa María I have observed reproductive pairs from March to October. Territories are formed in shallow water at the base of a rock, a cave is normally dug by the pair or an enclosed area chosen. Average females deposit approximately between three hundred and one thousand ovoid yellowish eggs close to 2 mm. in size in their larger axis. Pairs provides fry with food agitating the substrate with the belly and pectoral fins.
Acuarismo: A tank over 400 liters is necessary. Water temperature is best to be kept between 24 and 28 C in my opinion and water should be alkaline and hard, for the fish to be healthier and look its best. Fine substrate, log wood and rocks should be present for the fish to feel comfortable. They accept any aquarium food offered but it should be remembered they are mostly carnivorous in nature, a diet rich in carotene should be offered for them to show their intense colors during breeding time.
Conservación: Herichthys labridens es evaluada por la Unión Internacional para la Conservación de la Naturaleza en la lista roja de especies amenazadas como (EN) En peligro (1996). Listed in the Mexican Official Norm NOM-059-ECOL-2001 with classification A (In danger of extinction). Many years of experience with this species and its habitat show me that in fact this species may not be in danger of extinction, but it is vulnerable.
Comentarios: Herichthys labridens is a beautiful cichlid with a great potential for scientific research. The adaptation of the molar pharyngeal structure to feeding on snails in the springs of the valley of Rioverde, the unusual feeding of the fry, are topics that promise to show interesting conclusions.