(This article was originally published in The Cichlids Yearbook 5; 1995; Cichlid Press, Germany).
Nakajuka lagoon, one of the many lagoons around the lower course of the Grijalva/Usumacinta river system in Tabasco, México. Photo by Juan Miguel Artigas Azas. Inset: A male Thorichthys meeki inhabiting those lagoons. Photo by Ad Konings.
What is this beautiful fish?, I wondered many years ago looking at the cover page of Axelrod°s and Vorderwinkler "Encyclopedia of Tropical Fishes" (Axelrod & Vorderwinkler, 1974). The cover shows a superb photograph by Hans Joachin Ritcher of a proud male Thorichthys meeki with his gill covers and membranes complete expanded forward, in a menacing pose. The male guards his fry in a nicely aquascaped aquarium. When I learned more about this gorgeous fish, I was astounded to find out that this fish, Thorichthys meeki, could be found in my country, México. So at that time I decided I will surely go collecting it some day.
Years have pass since and to this day my admiration for this fish has never ceased, although I have actually collected and watch it many times in several parts of its natural range. And even to these days I have a breeding pair of this magnificent cichlid from Rio Candelaria, Campeche, swimming in my restricted tanks space.
The genus Thorichthys was erected by Seth Eugene Meek in 1904 (Meek, 1904) for grouping some small (no longer than 15 cm) Central American cichlids with a deep and compressed body, a small mouth and dorsal and caudal fins produced into long filaments, also present in the outer ends of the truncate caudal fin.
A distinctive trait of this genus is the presence of a black ocelated blotch in the sub-opercular area, a common feature now we know absent in one of the representatives, Thorichthys callolepis (Regan, 1905) from the upper reaches of Rio Coatzacoalcos, México. This blotch is used by the fish to deceive his potential enemies into believing they are much larger than they actually are. They do this by extruding their gular pouches frontwards, showing their ocellated blotches that then give the appearance of more separated and bigger eyes.
The type species of the genus was designated by Meek as Thorichthys ellioti. The meaning of the word Thorichthys is defined by Meek as a leaping fish. Meek's account on the matter goes as follows: "These little fish (i.e. Cichlasoma helleri) are exceedingly numerous in small isolated ponds, especially where there is a considerable amount of vegetation. they are attracted by anything which enters the water and will jump out of it in an apparently playful mood. When abundant they are easily caught, for as soon as your finger touchs the water, they will come leaping towards you". However, I must confess in many occasions I have been around this fish I have never see them leaping. Meek's account must have had more to do with hungry isolated fish, problably in a small pool after the rainy season, than with a joyfull actitude on the fish part. Our days possibility of observing such a behavior is however very much reduced, as such jumping fish will quickly end up in a fish soup somewhere.
Thorichthys are nevertheless referred in their natural habitat as "Toritos" by locals, Spanish word meaning "Little bulls", in consideration of this cichlid behavior of pairs threaten neighboring conspecifics by opening their gills and start lunging and retreating in short distances repeatedly. It is funny how "Toritos" resemble the word "Thorichthys" anyway.
Regan (1905) in his "Revision of the Fishes of the American Cichlid Genus Cichlosoma and of the Allied Genera" considered this genus as a section of the Cichlasoma (Regan thought Cichlosoma was grammatically more correct than Cichlasoma) , but after the decline of this powerful genus (Kullander, 1983), it seems the Thorichthys genus will soon recover its position again. Thorichthys meeki was described as Thorichthys helleri meeki by Brind in 1918, on the basis of aquarium specimens collected in "cenotes" (open wells) near the city of Progreso, Yucatán, México (Hubbs, 1936). The description of this fish was published in an aquarium journal (Aquatic life, 3, May, 1918: 119) and according to Hubbs "Not very adequately described and badly figured", although he is the first to recognize the name Thorichthys should be used. Even with priority over Cichlasoma meeki Hildebrand 1925, who referred to an unrelated species from El Salvador (Cichlasoma guija Hildebrand 1934). T. meeki was called by Brind "The scarlet chanchito" describing its life coloration as "A brilliant scarlet suffusion and striping extend from the throat and lower gill covers back and beyond the extremities of the pectoral fins."
|Pichucalco river, Grijalva system, home of Thorichthys meeki. Photo by Ad Konings.|
|A Thorichthys meeki male in normal coloration,photographed in the Pichucalco river near Baños del Azufre, Tabasco, México, Rio Grijalva system. Photo by Ad Konings.|
Thorichthys meeki has a wide distribution, it can be found from tributaries of the lower Grijalva river north to the upper part of the Yucatán peninsula along the Mexican gulf slope (North Latitudes 17°30° to 22°30°, West longitudes 88° to 93°). This includes Rio Pichucalco, the lagoons around the lower Grijalva and Usumacinta rivers from the city of Villahermosa north to the gulf, Rio Usumacinta, Rio Chompán, Rio Candelaria and the last northern Yucatán major river Rio Champotón, beyond this point north it will be found in most "Cenotes" over the western and northern part of the peninsula. this fish will just live in the lowlands, presenting geographical variations in several parts of it°s range.
A geographical variation of the fish with yellow on the flanks it is also found as far as north Belize in rivers Hondo, New River, Belize and Siboon. In Guatemala is found in some tributaries of Rio de la Pasión, also a tributary of Rio Usumacinta.
The rainy season in the Thorichthys meeki range extend from May to October, although as is usual in the rain or tropical forest, rains can be expected even in the dry season, although in lower intensities.
The habitat of the fish is distinguished by slow flowing muddy rivers or lagoons of very low visibility to small rivers of rather clear flowing water, clear water deep open natural wells "cenotes" and shallow brackish lagoons near to the sea "cienegas."
The distribution area of Thorichthys meeki is characterized by tropical forest, although in the areas around Villahermosa large extensions had been cut to leave space to cattle raising, an important economic activity in the area. In this region water is abundant an some times some of the ponds where meeki is found abundantly will dry out during the dry season, refilling again with the increase in level of larger surrounding lagoons with rains.
Those ponds are normally shallow, most of the times no more that one meter deep, with muddy bottoms, murky water and temperatures ranging from 28° C to over 32° C. The only vegetation found are floating plants most likely water lilies. The bottom of the ponds is littered with fallen leaves found in patches and from time to time some sunken branches that once belonged to surrounding trees.
The density of fishes found in this ponds is astonishing, a throw of the casting net will yield tents of fishes, mainly cichlids. Cichlid conspecifics include Astatheros robertsoni, Archocentrus octofasciatus, 'Cichlasoma' salvini, Parachromis friedrischstahli and 'Cichlasoma' urophthalmus, Paratheraps bisfasciatus, Petenia splendida, Thorichthys pasionis, other conspecifics include members of the fish familes Poecilidae; Poecilia petenensis, Poecilia mexicana, Gambusia sexradiata, Carlhubbsia kidderi, Phallichthys fairweatheri and Belonexos belicianus, Pimelodidae; Rhamdia guatemalensis, Atherinidae; Atherinella alvarezi, Characidae; Astyanax aeneus and Hyphessobrycon compressus, Cupleidae; Dorosoma anale and Dorosoma petenense, Rivulidae Rivulus tenuis and an assortment of other fish families representatives.
It is in this habitat that perhaps the most beautiful geographical form of Thorichthys meeki is found, a fish with an intense red lower half area, a shorter and higher body and a beautifully red colored high dorsal fin rarely exceeding 10 cm in total length. It is also in this area that some of the Thorichthys meeki individuals (regardless of its sex) will show no red at all. Why this happens is unknown.
Riverine Thorichthys meeki show a slightly more elongated body form and more blue speckles gleaming over the flanks, the red is intense but not as much and as extended as in the Thorichthys meeki from the lagoons.
In the rivers the Thorichthys will be found in the slower flowing areas over sandy bottoms littered with fallen leaves and driftwood. Visibility in these rivers may range from one to five meters in the dry season depending on the place.
In the Campeche rivers (Rivers Chompán, Candelaria and Champotón) we will find Thorichthys meeki living together with other cichlid species and many other fish families representatives. Cichlids are Astatheros robertsoni, 'Cichlasoma' pearsei, 'Cichlasoma' urophthalmus, 'Cichlasoma' salvini, and 'Cichlasoma' heterospilum, Parachromis friedrischstahli, Thorichthys pasionis and T. helleri (This last synonymized with Cichlasoma champotonis Hubbs, 1936), Paratheraps synspilus and Petenia splendida. Other fish families representatives are mostly the same than in the Tabasco ponds.
Thorichthys meeki also habits the clear water "cenotes" (from Mayan word "tzonot") and salty "cianegas" (brackish lagoons near the sea) on the western Yucatán peninsula. These open wells are most times interconnected by large subterranean rivers and can be very deep in some cases, it seems that the farther from the sea, the deeper they will be. Cenotes will have normally colder water than the rivers, presenting normally precipitous walls and sandy to rocky bottoms, where a slow current can be felt. A few cenotes do not seem to be interconnected with others and the water in these cases is stagnant and thermally stratified with low visibility. Hydrogen sulfide is found in the deeper areas of the stagnant cenotes, few fishes can be expected in these cenotes.
It is from cienagas near the city of Progreso in the northern coast of Yucatán that the Thorichthys meeki we have know for many years in aquariums comes from (Hubbs, 1936). I should add that this is not the most colorful variant, red in the flanks being more likely deep orange and fish maximum length close to 15 centimeters.
Water measurements in the Thorichthys meeki habitat can be expected to show alkaline readings with pH in many cases over 8.0 and hardness levels from hard to very hard. Temperatures are higher in the ponds near Villahermosa (28°C to 32°C), lower in the rivers (25° to 28°) and still lower in the cenotes (20° to 25°), cienagas along the sea can be expected to be as warm as the ponds of the lower Grijalva river.
The observations that follow on this fish were mainly done in Rivers Pichucalco, Candelaria and Champotón. Not observations were done in the Tabasco ponds due to the impossibility of observing underwater in the murky water. Observations in the cenotes have not been made by me so far.
Thorichthys meeki inhabits the slow or stagnant waters of rivers and ponds, they are normally found in groups in shallows although not schooling, they will normally look for the cover of overhanging vegetation or driftwood in the habitat.
Adult males will normally hold small territories regardless they are breeding or not, this territories will be defended by the holder against cichlid intruders by showing his typical menacing pose expanding gill plates and membranes that give him a larger appearance, violence will rarely take place, as the fish will normally manage to intimidate intruders. Females and smaller males will wander slowly through the shallows looking for food. This will be done by shoveling their large snouts in the soft substrate for posteriorly filtering it in search for something edible. Once filtered matter will be mostly expelled through the gills, males will follow this feeding fashion in their territories. Thorichthys are mainly carnivorous fish feeding on small inverts found in the mud.
Breeding activity will normally take place in the dry season from February to May, big rains in this months will normally wash away the babies and breeding efforts will have to be started all over again.
Territories of males will normally be found among some protective areas in the form of water plants (Foxtail like, water lilies or Vallisneria) , driftwood or rocks. Passing females will be courted by the male showing his flanks with undulating movements and open gills, females will decide then between ignoring the male and get away from his territory or follow his court side by side and join him in the territory, this however will not happen in the first try, but females will court and leave the male°s territory more than once.
Once pairs are formed they will clean up a surface, they seem to prefer a sunken large leave in the territory, where they will place their two millimeters clear yellowish eggs numbering in the couple of hundreds. The typical Thorichthys fashion for this is the eggs being laid by the females separated from each other and immediately being followed closely by the male fertilizing them, the separation of the eggs in contrast with other cichlids may be explained by the normally low oxygen content in the Thorichthys meeki habitat. Spawn may take around two hours and eggs will be closely fanned and watched over by both parents until hatch occurs (Two days under aquarium conditions), wrigglers will become free swimming after several days (Four to five days in aquarium) and at this point they will swim around together under the close supervision of the parents that will lead them with spasmodic movements of the body and fins, Normally one fish will stay just above the free swimming fry while the consort scares away intruders. Should one of the couple miss, the other will take the breeding responsibilities alone. Thorichthys meeki will spawn and breed in colonies of several neighboring pairs and apparently rarely the fry will be taken far away the spawning site.
Fry will feed on organic matter on the surfaces of the habitat, with the parents carefully supervising this activity. Males won°t abandon their babies even in the presence of larger threats like a close look of a curious human swimmer. Once fry reach about one centimeter they will abandon their parents and go to the shallow edges of the water body where they can be observed in large numbers foraging on the bottom.
Predators of Thorichthys meeki are present in good numbers in the habitat. There are king fisher birds all along cichlid range, as well as otters, caimans, snakes, turtles and larger piscivorous fish, like Petenia splendida and Gars that will potentially prey on the fish.
A Thorichthys meeki fry caring male in Rio Pichucalco, Tabasco, México. Photo by Juan Miguel Artigas Azas.
|A breeding pair of Thorichthys meeki in Rio Pichucalco, Tabasco, México. The male can be seen taking care of the eggs deposited on a fallen tree leaf (center of the picture). The female is digging some pits for post-hatching placement of the unmovil wrigglers. Photo by Juan Miguel Artigas Azas.|
|A Thorichthys meeki female taking care of her spawn on the leaf below her. Eggs are placed separated from each other possibly for maximum oxygenation. Rio Pichucalco, Tabasco, México. Photo by Juan Miguel Artigas Azas.|
Aquarium keeping of this fish has been popular for more than seventy years as has been recorded in dedicated magazines. It°s beautiful colors and interesting behavior, as well as the relatively small tanks it demands for his well being and aggression control will surely keep it as a favorite for many years to come. As it has been shown this year in the American Cichlid Association annual convention in San Antonio, TX., where a beautiful male of this specie won best of show. More colorful potentially soon introduced geographical variants will surely help in keeping this fish around. I am also glad to say that up to this days it doesn°t seem to be endangered in his natural habitat, thought the potential dangers laying around, among them: Oil exploration, untreated industry wastes, habitat destruction by cutting away the surrounding forests. Dangers that we will have to close monitor on them.
- Axelrod & Vorderwinkler, 1974, Encyclopedia of Tropical Fishes, T.F.H.
- Hubbs, Carl , 1936, "The Cenotes of Yucatán, a Zoological and Hydrographic Survey", Carnegie Institution of Washington, p. 259-260.
- Kullander, Sven, 1983. "A revision of the South American Cichlid Genus Cichlasoma (Teleostei: Cichlidae)", Swedish Museum of Natural History, Stockholm.
- Meek, Seth Eugene, 1904, "The fresh water fishes of México north of the isthmus of Tehuantepec", Field Columbian Museum, Vol. V:1-252.