(This article was originally published in Freshwater and Marine Aquarium Magazine, May 1982; pp. 6-11, 86-94. It is here reproduced with the permission of author Dr. Paul V. Loiselle).
(Editor Note by Juan Miguel Artigas Azas: The present article as originally appeared, was released before the publication by Kullander in 1983 of "A revision of the South American Cichlid Genus Cichlasoma (Teleostei: Cichlidae)." In this publication, the genus Cichlasoma is restricted to some South American species closely related to the type species, Cichlasoma bimaculatum. Since then, the Herichthys genus has been accepted by people working with Central American cichlid taxonomy. In an attempt to avoid confusion and take advantage of the possibility of updating electronic publications in the WWW, I have updated in this article the genus name of Herichthys cyanoguttatus and other Herichthys species mentioned in this paper to reflect their current generic status. For details, please check the document in this home page about Herichthys).
The Family Cichlidae enjoys an essentially tropical distribution, the majority of species occurring between the Tropics of Cancer and Capricornio. However, a handful of outriders push the distributional limits of the family well beyond these traditional climatic boundary lines in both the Old and New Worlds. These outrider species may be considered pioneers in the aquaristic as well as the biogeographic sense, for they figure prominently among the ranks of the first cichlids to be imported as aquarium fish. To a certain extent, this was due to historical accident. Both southern Brazil and México, to cite two early foci of fish exportation, boasted important expatriate German communities in the late 19th and early 20th centuries and enjoyed regular steamship links with such ports as Frankfurt and Hamburg. Of equal importance in explaining the early successes of such extratropical cichlids may have been their ability to withstand low water temperatures. Modern aquarists, blessed with reasonably priced, reliable thermostatic heaters can barely conceive how great a problem overwintering ornamental fishes often proved in the early days of the hobby. Yet, these cichlids obviously had more going for them than mere hardiness. Many have continued to enjoy favor long after developments in aquarium technology allowed the establishment of less cold-resistant competitors among the ranks of ornamental fishes. An excellent example of such a perennial favorite in the subject of this article, Herichthys cyanoguttatus. Known by the vernacular designation of Texas cichlid in North America, this species is the only representative of the Family Cichlidae native to the United States.
Any effort to write about this most attractive animal from a historical perspective is complicated by the fact that as it has been generally utilized in the scientific literature, the name H. cyanoguttatus refers to a complex of rather similar fishes. Alvarez (1970) recognizes three distinct subspecies. From north to south, these are:
- Herichthys c. cyanoguttatus (Baird and Girard, 1854), native to the Rio Grande-Rio Conchos drainage of Texas and northeastern México.
- Herichthys c. temporatum (Fowler, 1903), found in the Rio Soto la Marina basin, in the Mexican state of Tamaulipas, immediately to the south of the Rio Grande-Rio Conchos system and;
- Herichthys c. carpintis (Jordan and Snyder, 1899), described from the Laguna Carpintero inside the city of Tampico and also found in the lower reaches of the Rio Pánuco.
Herichthys pavonaceum (Garman 1881) is presently regarded as a junior synonym of H. cyanoguttatus. However, the possibility must be considered that H. pavonaceum, originally described from material collected from springs in the vicinity of Monclova, may actually be the correct name for the dentally polymorphic Herichthys species from the nearby Cuatro Cienegas basin currently being studied by Dr. Irving Kornfield and his associates (Smith, 1981). The Cuatro Cienegas basin is not far from Monclova and Garman's description of the color pattern of his H. pavonaceus strongly suggests either a female or a sexually quiescent male of the mojarra de Cuatro Cienegas than it does any subspecies of H. cyanoguttatus. (Editor note: Herichthys pavonaceus has now been synomymized with Herichthys cyanoguttatus in the description of Herichthys minckleyi by Kornfield and Taylor, 1993).
A young male Herichthys carpintis. Known as the green texas cichlid to American aquarists, this is the species widely maintained in Europe under the erroneous name of Herichthys cyanoguttatus.
This photo of a female Herichthys carpintis cleraly shows the large, discrete metallic spangles in the head and opercular region to which Jordan and Snyder referred in the original description of the life colors of this species.
A young male mojarra de Cuatro Cienegas. A representative of H. cyanoguttatus species complex endemic to this isolated drainage basin in northeastern México. Older males turn rich, velvety black retaining blue spangles on body and fins.
A young, sexually quiescent female mojarra de Cuatro Cienegas. The serially repeated pattern of black lateral spots is strongly reminiscent of Garman's description of the color pattern of his Herichthys pavonaceus.
Two distinctively colored cichlids have been called by the name H. cyanoguttatus in the aquarium literature. The fish best known to American aquarists and the subject of this article are descended from breeding stock collected in the lower Rio Grande. They may with absolute propriety be referred to as H. cyanoguttatus, for the type locality of this species is Brownsville, Texas, at the mouth of the Rio Grande (Baird and Girard, 1854). The vernacular names of Texas cichlid and Rio Grande perch, bestowed upon this species by sport fishermen and aquarists are at best somewhat misleading. While native to the Rio Grande, this fish is not a true perch, and the greater portion of its range lies in northern México, not Texas.
As can be seen from the accompanying illustration, the second member of this complex, known to American hobbyists as the green Texas cichlid, differs quite 1ramatically from H. cyanoguttatus in coloration. Differences between breeding animals are even more pronounced than the photographs comparing sexually quiescent animals would suggest. The green Texas always conveys a distinctly spangled overall appearance. On the other hand, sexually active individuals of H. cyanoguttatus are characterized by a lightening of the base color anteriorly so pronounced that the small iridescent blue dots upon which the specific either is based effectively vanish. The green Texas also has a more pointed head, and males develop a far more pronounced frontal gibbosity than do comparably large males of H. cyanoguttatus. In a free choice situation, these two fish will not hybridize. Indeed, I suspect that even forced hybridization of these two cichlids might prove extremely difficult to effect. I have seen a widowed, obviously very ripe female green Texas actively courting a male C. salvini while totally ignoring the overtures of a male H. cyanoguttatus living in the same aquarium.
The green Texas corresponds in all salient respects to H. c. carpintis sensu Alvarez. Jordan and Snyder (1899) in their description of the life colors of their Neetroplus carpintis emphasize the presence of large round and elongated greenish-blue spots on a golden brown background in the cephalic region, while their excellent illustration is clearly that of a sexually quiescent green Texas cichlid. Given that both of the animals in question behave as valid biological species, there seems little point in perpetuating Alvarez's trinominal scheme of nomenclature and I will, henceforth, treat these fish as full species.
The available documentary evidence points to H. carpintis as the first representative of this species complex to be imported into Germany in 1902 (Sterba, 1966). Every description of H. cyanoguttatus I have encountered in the German aquarium literature corresponds to this fish, as do all the aposite illustrations. In retrospect, this is not really surprising. The difficulties involved in making a shipment of fish from the Tampico area to Germany in the first decade of the century would have been trivial compared to those entailed in exporting fish from the lower Rio Grande. To judge from the reactions of British and German participants at the British Cichlid Association's 1981 Convention, when showed slides of H. cyanoguttatus, I seriously doubt that this species was ever available in Europe within the lifetime of any member of the audience, if indeed it had ever been imported at all!
This state of affairs complicates efforts to establish the aquarium debut of H. cyanoguttatus in the United States. It must have been commercially available in the late 1920's and early 1930's, for Innes (1935) illustrated this species in the first edition of Exotic Aquarium Fishes. Tracking it back any further would require a more extensive collection of early aquarium literature than I boast. I suggest it as an interesting project for a cichlid fancier with bibliophile tendencies. The precise date of importation of H. carpintis into the United States is also a mystery. I saw it for the first time in 1971. The fish in question were the progeny of a pair collected in México by a vacationing aquarist. Though the shop in question sold many of their fry, I never saw the fish for sale subsequently in the San Francisco Bay area. I have seen it offered for sale twice since, each time in a different part of the United States. This suggests a commercial source, but whether it is domestic or foreign I have been unable to determine. Be that as it may, unlike H. cyanoguttatus, H. carpintis is far from generally available in the United States and well worth the trouble of acquiring whenever it is encountered.
The Texas cichlid was originally described as Herichthys cyanoguttatus by its authors. Most older aquarium references follow this usage (Axelrod and Schultz, 1955; Axelrod et al., l962; Frey, 1961; Innes, 1935). Baird and Girard based their new genus upon dental characteristics. In their opinion, the mixed buccal dentition of their species, comprising truncate teeth anteriorly and conical teeth posterolaterally, differed sufficiently from the uniformly conical dentition present in Heros ( = Cichlasomines) to warrant erection of a new genus to contain it. Their contemporaries did not unanimously accept this position. Neither Gunther (1863) nor Eigenmann and Bray (1894) recognized the validity of Herichthys, which was saved from the taxonomic scrap-heap chiefly by Regan (l905), who resurrected the taxon to include two additional species from southern México and Guatemala with similar mixed dentition in the jaws.
The American ichthyologist Seth E. Meek appears to have been the first to point out (1914) that the tendency towards a truncate anterior dentition within the species assigned to such genera as Herichthys, Paraneetroplus and Tomocichla displayed too much variability to be a useful defining characteristic. It is now known that the sort of truncate dentition that led to the erection of Herichthys and the placement of Herichthys carpintis in the genus Neetroplus is really an ecophenotype. Fish that live over and forage through abrasive substrata quickly wear the tips from their originally conical anterior teeth. However much it may have puzzled ichthyologists, this state of affairs occasions no great difficulties to the fish, who have the ability to replace seriously worn teeth. The history of the genus Herichthys illustrates nicely how ichthyologists have come to understand how developmental processes and environmental influences can interact to influence the phenotype of a fish. Consequently, modern workers tend to be somewhat more conservative in their definition of cichlid genera, preferring to rely upon characteristics less likely to reflect such interactions than dental morphology in their interpretation of evolutionary relationships.
The slowness of aquarists in accepting the suppression of Herichthys is not entirely to be faulted, as not all ichthyologists found themselves in agreement with Meek's conclusions as to its status. In roughly contemporary papers published some years later, Samuel Hildebrand (1930) concurred with Meek's reasoning, while Carl Hubbs (1935), citing Regan as his authority, held out for retention of Herichthys as a separate genus. The most recent papers dealing with the relationships of Mesoamerican cichlids (Miller and Nelson, 1961; Miller, l966) treat Herichthys as a subdivision of Cichlasoma. This position is generally held by cichlid systematists at present. Recent reference works on aquarium fishes (Goldstein, 1970, 1973; Mayland, 1978; Sterba, 1966) reflect this position.
Herichthys cyanoguttatus was originally restricted to the southern half of the Rio Grande in the United States. Physiological limitations apparently restricted its expansion into the northern reaches of the Rio Grande and its major American tributary, the Pecos River. Clark Hubbs (1951) found that this species was incapable of tolerating temperatures below 14°C. for any length of time. Expansion eastward into waters warm enough to sustain persistent populations was blocked by physiographic barriers that have been surmounted through human intervention. The Texas cichlid is now widely established in the Guadalupe River basin and in the Edwards Plateau region of central Texas (Brown 1953). The prevalence of constant temperature spring flows in this area affords H. cyanoguttatus the winter refuge necessary for the maintenance of a permanent presence in the area. Feral populations of the Texas cichlid have also been reported from central Florida. These are presumably the descendants of fish farm escapees. See Birkenhead (1978) for a map of this species' distribution in the United States.
There is surprisingly little published information on the natural history of H. cyanoguttatus. The most comprehensive study of this cichlid to date is a doctoral thesis not generally available to the public save in abstract form (Buchanan, 1972). The lack of interest shown in this species by governmental research agencies is to a degree understandable. Though ii can grow up to 25.0 cm SL under favorable conditions in captivity, the Texas cichlid seldom attains such dimensions in nature. In the eyes of recreational fishermen it compounds this transgression by stunting readily under the conditions prevalent in reservoirs. Thus, from the perspective of fisheries management personnel in the United States, H. cyanoguttatus is not large enough to be classified as a sport or pan fish yet is too large and spiny to be a good forage or bait fish for more highly regarded game species. It thus falls effectively outside the scope of their interest and activities. Interestingly enough, this is not the case in México. There the mojarra huasteca (Editor Note: Actually guapota), as both H. cyanoguttatus and H. carpintis are known locally, is considered a legitimate food fish. Consequently there is considerable interest in understanding more about its biology. Dr. Salvador Balderas-Contreras of the Universidad Autonoma de Nuevo Leon has a number of students investigating the interactions of this species with various introduced food fish such as the channel catfish, lctalurus punctatus, and the blue tilapia, Sarotherodon aureus. The results of these studies promise to be most interesting.
Herichthys cyanoguttatus has also drawn a blank as a subject for behavioral studies, though European workers are not unacquainted with H. carpintis in this context. The reasons for this scandalous neglect of the only representative of the Family Cichlidae native to the United States by American researchers are not obvious. Perhaps as fiscal constraints and political unrest in Central America combine to make field work on the cichlids of that region neither practical nor prudent for American students of cichlid ecology and behavior, the virtues of studying a more readily accessible Central American cichlid species will become more apparent.
The Texas cichlid is certainly easily maintained. Like the majority of Mesoamerican cichlids, H. cyanoguttatus will prosper in any potable water and actually seems to prefer hard, alkaline conditions. As one might expect in an inhabitant of a river characterized by intermittent flow, this species can tolerate fairly high dissolved metabolite levels for brief intervals without coming to harm. Texas cichlids nevertheless do much better and are certainly more likely to spawn when maintained under a regime of regular partial water changes. As previously indicated, this species can tolerate temperatures as low as 14°, though a range of 22°-25°C. is more to its liking for ordinary maintenance and breeding.
This is also an easily fed cichlid. In nature, the Texas cichlid is an omnivore with strong herbivorous tendencies. Buchanan (1972) found that in the lower Rio Grande, H. cyanoguttatus took a wide range of food items, but that introduced populations on the Edwards Plateau were almost completely herbivorous. He explained the shift in feeding pattern in terms of competitive interactions between the Texas cichlid and a more diverse assemblage on centrarchids than occurred in the cichlid's native waters. Any of the usual live and prepared foods are voraciously devoured in captivity, though economic considerations usually dictate a reliance on the less expensive pelletized foods as a dietary mainstay. Frozen fish and shellfish, shredded in a food processor, are also eagerly taken, as are leafy vegetables pre-softened by a quick dip into boiling water, Large Texas cichlids are also fond of snails. Even specimens in the 7.5 cm-12.0 cm range will do a good job of eradicating ramshorn and pond snails from an infested aquarium if kept on short rations for a few days. The Malaysian livebearing snail is, in its larger sizes, a bit more than the Texas cichlid can handle. However, though adults manage to resist maceration by this species' pharyngeal mill, enough juveniles are simply swallowed whole to effectively slow the increase of this generally useful snail in tanks where the two are kept together.
It follows from the foregoing that H. cyanoguttatus is hardly a good candidate for life in a Leiden-style planted aquarium! Rockwork and driftwood, real or ersatz, make highly functional and esthetically pleasing furnishings for its quarters. As with most Cichlasomine species, a layer of floating plants is appreciated for the cover it affords from disturbing overhead movement. Nor, though it hardly qualifies as piscivorous in nature, is the Texas cichlid a good neighbor to tankmates small enough to be easily swallowed. That caveat aside, this species is a satisfactory community tank resident. As pairs are intolerant of one another, the general rule is one per tank in aquaria under 400 liters capacity. Heterospecifics are typically ignored outside of periods of reproductive activity. While breeding pairs will effectively sequester a portion of the tank for their own use, they do not display the lethal efficiency of other, often smaller substratum spawning cichlids such as C. salvini or Hemichromis elongatus in defending their progeny. Given a large aquarium (300 1-500 1 capacity), there is certainly no reason why the Texas cichlid cannot be allowed to breed in a community situation. The digging of which this species is often accused is largely restricted to periods of sexual activity. Its scope may be greatly minimized through the use of a gravel coarser than is customarily employed as the substratum in its aquarium.
As one might expect given its distribution, H. cyanoguttatus in nature is markedly seasonal in its reproductive pattern. Spawning has been observed from March through August, with a distinct peak in April (Buchanan, 1972). In captivity, the Texas cichlid spawns readily throughout the year. The simplest way to induce successful spawning is to rear a group of fry to maturity in a community situation, then remove -all save the first pair to form before the honeymooners can do in their sibs. Surplus fish can often be traded back to a retail shop or else inflicted upon as yet unaddicted hobbyists via a local aquarium club's prize table. Those who lack the patience to grow a group of youngsters to maturity need not despair of having the Texas cichlid spawn in their tanks. Young adults in the 7.0 cm-10.0 cm SL range are frequently available at retail establishments. Such young adults usually pair up with a minimum of difficulty in a community situation. Texas cichlids are easily sexed even when quite small. Females boast an indistinct black blotch in the spiny dorsal that males lack. Females are generally smaller and chunkier than males and have more rounded soft dorsal and anal fins, though this distinction is not as apparent in this species as it is in some of its congeners. Large males tend to display a certain amount of frontal gibbosity, though the nuchal hump even in 17.0 cm-20.0 cm SL species never approaches the level of development seen in H. carpintis of the same size (Vide Goldstein  and Mayland  for photographs of large males the latter species).
As in other Cichlasomine species, pairing in the Texas cichlid is facilitated when the fish are maintained in a community situation. Difficulties arising from efforts to spawn this species are almost invariably the consequence of trying to induce pair formation in isolation. If such an approach must be employed, I recommend recourse to the incomplete divider technique (Loiselle, 1981). Serious injury to, or the death of, the female is otherwise the most probable outcome of such an effort. In a community situation, courtship tends to be perfunctory, typically consisting of low level opercular flaring and reciprocal lateral displays. Most aquarists overlook such behavior and are in consequence quite surprised by the "abrupt" onset of territorial defense by two previously unattached individuals!
First row left: Preparation of the spawning site is an essentially female responsability in Herichthys cyanoguttatus. the male is largely preoccupied with keeping intruders at a distance both before and after spawning. First row right: The female also carries out most of the excavation of the pit that will receive the newly hatched fry. Coarse gravel, possibly because of the difficulty with which it is moved, tends to inhibit gratuitous excavation in this and other Cichlasomanine species. Second row left: The female usually makes several "Dry runs" over the site before settling down to spawn in earnest. Second row right and third and fourth rows: Spawning follows the usual Central American cichlid pattern. The male closely follows his mate as she moves over the previously scoured site depositing eggs. Very few eggs go unfertilized. Fifth row: The male patrols the perimeter of the spawning territory while the female fans and cleans the developing eggs. In captivity, the male will usually relieve the female long enough for her to grab a few bites at feeding times. Sixth row left: The female chews the fry out of their eggs shells and spits them into the pre-dug pit. Sixth row right: This parental female clearly displays the bi-color pattern characteristic of both sexes at this time as she supervises the foraging of a few of her two week old spring. Both sexes participate actively in the care of the mobile fry, though the male seems less attached to their immediate vicinity.
Most of the actual preparation of the spawning site falls to the female under aquarium conditions. The Texas cichlid does not appear to be choosy about where it will place its eggs. This species will spawn at the bottom of a pit dug into the substratum, but in captivity, a solid surface is usually selected. The pair depicted in the accompanying photographs had a predilection for vertical surfaces, but I have had other pairs spawn quite happily on current-polished quartz rocks or flat pieces of sandstone. Regardless of its nature, the prospective spawning site is vigorously "scrubbed" by the female before being put to use. Both sexes may cooperate in digging a pit adjacent to the spawning site, but here again, the female does most of the work while her mate keeps intruders at a distance. The amount of excavation a pair will undertake appears to be influenced by both the texture of the substratum and the number and nature of their aquarium's other inhabitants. Coarse gravel, such as used in the aquarium depicted herein, inhibits massive excavation, probably because it is less easily manipulated than the usual grade of aquarium gravel. The amount of time and energy available for earthmoving projects also falls off dramatically when a pair has to exert itself continuously to preserve the integrity of its breeding territory.
The appearance of a conspicuous ovipositor in the female and genital papilla in the male may be taken as signs that spawning will occur within 24 hours. The mechanics of spawning, as depicted in the accompanying photographs, do not differ from the norm for the genus Herichthys. Even without interruptions, spawning may require several hours to complete, for H. cyanoguttatus is a very prolific cichlid. Though she only measured 7.0 cm SL at the time, the female of the pair illustrated herein produced spawns of up to 500 eggs. A large female, C. 18.0 cm SL, can spawn up to ten times that number. That few if any eggs fail to develop speaks eloquently of the male's ability to rise to the challenge of his essential function!
As is usual in the genus Herichthys, the female fans and picks detritus from the eggs while the male defends the periphery of the territory against intrusion by potential , spawn predators. The two fish will occasionally swap off responsibilities, usually at feeding time. This arrangement allows the female to snatch a bite or two with minimal risk to her brood. It is not uncommon for the male of isolated pairs of Texas cichlids to completely usurp the hygienic functions normally exercised by the female. The consequences of such a deviation from the usual division of labor between the sexes are usually quite unpleasant for the female. Her survival at this juncture depends largely upon the availability of suitable cover in the breeding tank. Such hyperparental males may relax their monopolistic attitude once the fry are mobile, but it is unwise to count on such a change in behavior. Removing the female as soon as such a situation is noticed is by far the most prudent course to follow, as the male can handle matters quite satisfactorily by himself. it is better yet to prevent the occurrence of such problems by having target fish available from the onset of the breeding cycle (Loiselle, 1979, 1981). Such an arrangement channels the male's behavior along more normal pathways. The result is a closer approximation of the division of labor seen in nature.
At 25°, the eggs are ready to hatch three days postspawning. The wrigglers are chewed out of their eggshells by the female and placed in a pre-dug pit. In my experience, they are not moved very frequently during the interval between hatching and the attainment of mobility. This pair never moved their progeny at all. It would be interesting to know how frequently, if at all, the wrigglers are shifted in nature. If such behavior had evolved in response to the activities on nocturnal, scent-hunting predators such as catfish, one might expect its attenuation in an environment where such predators are relatively uncommon, such as the lower Rio Grande basin, which supports only two ictalurid catfishes likely to pose a threat to cichlids at this stage of development.
The fry are free-swimming four days posthatching. They can take Artemia nauplii and finely powered prepared food immediately. Their parents will also chew up chunks of food and expel out the resulting cloud of particles for the fry to forage through. Contrary to Sterba's account (1966) of the parental behavior of H. carpintis, H. cyanoguttatus experiences little difficulty in defending its progeny for the first week to ten days of their mobile existence. By this time other fish in the same tank have usually learned the hard way that the two-tone silvery white and black fish are nothing but trouble and hence best given a very wide berth. This initially facilitates the parents' task. The school of fry usually begins to shrink dramatically once they pass the ten day mark. At this point they become less responsive to parental signaling and more apt to swim outside the zone effectively protected by their parents. I usually net out a few dozen fry at this juncture and simply allow nature to take its course. Predation on the remaining young increases as their parents begin to lose interest in their defense. This situation is apparently triggered by the onset of a new ovarian cycle in the female, sometime between the third and fourth week posthatching. If the tank is well-furnished with cover, one or two fry per spawning will survive and grow large enough to escape predation by its other inhabitants, an outcome not greatly different from what transpires in nature.
Under a regime of heavy feeding and frequent partial water changes, the fry will grow to 2.0 cm-3.0 cm SL within eight weeks posthatching. They are less inclined to cannibalism than are some of their congeners, but it is still a good idea to sort out smaller individuals for separate rearing if one wishes to end with a balanced sex ratio. The young attain sexual maturity c. eight months postspawning at a length of 5.0 cm SL for females, slightly larger for males.
While they have not neglected it to the same extent as they have most other native aquarium fishes, American aquarists do have a tendency to take the Texas cichlid for granted. The tendency to defer maintaining a commonly available fish in order to devote time and tank space to a demonstrably rare species is certainly understandable. However, rarity is but one of the attributes that define a desirable aquarium resident. Attractive coloration, ease of maintenance and interesting behavior also must be considered in this context. As the Texas cichlid clearly illustrates, the last three attributes are not inevitably linked to the first. So give our national cichlid a try. The experience should illustrate beyond any doubt that the best cichlids don't, inevitably hail from the other fellow's pond!
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