Thorichthys callolepis – San Domingo cichlid
Systematically, the genus Thorichthys is one of the most clearly defined genera in Central America. And yet here too we find a fish that does not quite swim within the lines. Thorichthys callolepis, the species with the smallest distribution area of all Thorichthyses, can rightly be called an outsider (Robert Rush Miller 1961).
The distribution area of Thorichthys callolepis is limited to the upper reaches of the Coatzacoalcos. They inhabit the faster-flowing streams and rivers, comparable to the trout area in Europe. Probably due to this somewhat different environment (for Thorichthys), the fish differs in a number of respects from its congeners. For example, it is slimmer and less tall, the extended fin rays and crescent-shaped tail are moderately developed and even the gill cover spot so characteristic of Thorichthys is missing. Furthermore, the dark spot on the flanks is further back than with other Thorichthyses and while Thorichthyses normally grow larger in our aquariums than in the wild, the opposite is the case with Thorichthys callolepis. Juan Artigas has measured specimens of more than 15 centimeters in the Coatzacoalcos. In our aquariums, on the other hand, they usually do not grow larger than about 12 centimeters and are therefore among the small ones. Perhaps a result of the lower oxygen content in our aquariums.
Etymology
Callolepis means “with beautiful scales” referring to the blue iridescent reflections on the scales. Synonyms: Heros callolepis, Cichlasoma callolepis.
Origin
Mexico.
Distribution
In the tributary rivers of the Coatzacoalcos. Rio Chalchijiapan, Solosuchil, Grande, Malatengo, Almoloya, and in the Rio Coatzacoalcos itself. Despite its small distribution area and local environmental problems, Thorichthys callolepis is not yet endangered.
Behavior
The fish is known for its milder temperament but knows how to hold its own when necessary. Side by side they defend their offspring against much larger opponents and do not stop at threats.
Diet
Carnivore. Small insects and their larvae that they pick from the bottom.
Breeding Thorichthys callolepis
In the last months of the dry season (around February) when the water is warmer and the flow is less fast, Thorichthys callolepis starts with a lot of dedication to its reproduction. To do this, they seek out the slightly sheltered banks, where they prefer to choose a small stone to spawn. Clutches are smaller than other Thorichthyses, on average no more than 200 eggs and considerably fewer in the aquarium.
The eggs are oval, amber-colored and barely noticeable above the surface. The female stands over the eggs and fans them with her pelvic fins while the male chases the intruders out of the territory. After 48 hours the eggs hatch and after 5 to 6 days the yolk sac is digested and the young swim freely. The offspring is tended by both parents. They do this by means of flaring with their red gill membranes and jerking movements of the entire body. Side by side they defend their young brood in a very decisive manner. They do not hesitate to attack much larger fish such as P. bulleris or P. reganis in the flank. After which they can turn in an instant to attack intruders from another direction (Heiner Garbe 1995). After about two months, when they are just over an inch in size, the young leave their parents and join large schools of young fish of all kinds. (Artigas Azas 2005)
The Aquarium
Thorichthys callolepis is not a beginner’s fish. It is one of the more difficult Thorichthyses to keep. The oxygen requirement of this fish is very high. Therefore a special aquarium for rheophilic species with overcapacity pumps. Temperature not above 25 C. and change half of the aquarium water every week. This way you get this variety large and beautiful.
Video
Author
Rene Beerlink – NVC
Reference
Described by Charles Tate Regan in “Descriptions of new or little-known fishes from Mexico and British Honduras” 1904. Magazine of Natural History. V.13: pp. 258-259. as Heros callolepis.
Literature
Hans A. Baensch, Dr Rüdiger Rielh, Aquarien Atlas Band 4, blz 688.
