Labidochromis, The Dwarf Mbuna

An adult male of the so-called Chipoke island Labidochromis. The color pattern and overall appearance of this undescribed species resembles so closely those of Pseudotropheus lucerna that close examination of the jaw teeth is necessary to make positive identification. Photo by Paul V. Loiselle.

One of the points I have attempted to bring home in this series of essays is that, as aquarium residents go, cichlids are pretty undemanding fish. Given a little forethought in his selection of species and a reasonable willingness to invest the time required to manage the nitrogen cycle in their aquarium, a hobbyist, regardless of where he lives, can anticipate a maximal return in viewing pleasure and spawning success for a surprisingly minimal expenditure of maintenance effort. This being the case, why aren't there ten times as many members of the American Cichlid Association as are presently on its roster? Why do so few wholesalers offer such a limited selection of cichlids to their customers and why do so many dealers refuse to stock a reasonable selection of these highly desirable fishes when they are available?

Simply summarized, why don't more aquarists keep cichlids? Leaving aside the variable of individual tastes in aquarium fishes, I suspect the underlying reason for this situation lies in the single non-negotiable demand cichlids as a group make of aquarists adequate living space. Virtually all of the undesirable behavior attributed to cichlids can be described as an artifact of a totally unnatural degree of crowding. Recognizing this problem and solving it are not, alas, one and the same thing. Behavior modification in cichlids translates to providing them with larger quarters. But larger tanks require more space and space is usually the one resource the aquarist has in shortest supply. With an increasing proportion of aquarists living in apartments, this situation is unlikely to change for the better. This is one reason why I devote what some readers consider a disproportionate effort to searching out and publicizing those cichlids whose behavioral attributes allow them to live satisfactorily in smaller aquaria.

Large tanks (>200 lt) are considered a prerequisite for the successful maintenance of the popular mbuna of Lake Malawi. This fact has deterred many aquarists with limited space from gratifying an understandable desire to keep these beautiful cichlids. Like much other conventional wisdom, this observation requires some qualification. While most representatives of the popular genera Pseudotropheus and Melanochromis are medium-size cichlids ranging from 10.0 cm to 15.0 cm SL, each has smaller representatives whose housing requirements are modest enough to recommend them to the aquarist whose space limitations preclude setting up tanks larger than 200 lt. capacity. It also overlooks the existence of genera comprised exclusively of species small enough to be considered dwarf cichlids. Neither of the two described species of Cynotilapia exceeds 8.0 cm SL, nor are larger specimens of Iodotropheus sprengerae encountered with sufficient frequency to warrant regarding it as anything but a dwarf species. But without question the mbuna genus richest in apartment sized species is the subject of this essay, the genus Labidochromis.

Though pleasingly colored, Labidochromis vellicans is far from being the most spectacular member of the genus. The lilac wash on the flanks and fins of this male is characteristic of the species. Males of some populations have an attractive rusty orange dorsum and head, which has led some aquarists to confuse L. vellicans with the Rusty Cichlid, lodotropheus sprengerae. Photo by Paul V. Loiselle.	An ovigerous female L. vellicans Because Labidochromis typically have small spawns, they seldom display the distended throat region most aquarists associate with a laden female mbuna. The combination of reduced food intake and increased respiratory rate are the most reliable indicators of maternity in fishes of this genus. Photo by Paul V. Loiselle.
Labidochromis fryeri was orginally marketed under the erroneous names Labidochromis caeruleus and Pseudotropheus minutus. The true L. caeruleus is a slenderer metallic blue fish with a conspicuous black submarginal band in the dorsal fin. The conspicuous anal pseudo-ocellus and the dark ventral and anal fin margins identify this specimen as a male. Photo by Paul V. Loiselle.	With regard to body coloration, L. fryeri is one of the most sexual1v isomorphic representatives of the genus. The coloration of this female is explanation enough of the frequently applied common name of Ice-blue Labidochromis, but individuals of both sexes with an overal-flesh pink wash are also occasionally encountered. Photo by Paul V. Loiselle.
This relatively deep-bodied, long-snouted Labidochromis is similar in many respects to L. fryeri, but differs in details of its jaw teeth and color pattern. This presently undescribed species seems not to have become established in the hobby. Photo by Paul V. Loiselle.	Labidochromis exasperatus the Likoma Island Pearl, is one of the most popular available species. The rusty orange longitudinal stripes display variability that is influenced by the origin of the fish it's dies. In some imported species the stripes are broad, vividly colored. In this tank-reared male they are barely evident. Photo by Paul V. Loiselle.

The genus Labidochromis was established in 1935 by Trewavas. The type of species, Labidochromis vellicans, was characterized by a small mouth, a pointed premaxillary arch and an outer row of slender, recurved conical teeth that increased in size from rear to front. The apices of the anteriormost teeth are opposed, which enables the fish to utilize them as a set of forceps in picking individual food items from the algal mat that covers the rocky shorelines where it habitually occurs (Fryer, 1959). This extremely specialized feeding apparatus has evolved independently twice in Lake Tanganyika, where Tanganicodus irsacae Poll fills the Labidochromis feeding niche in the surge zone, to be replaced by the several Julidochromis species in water a meter or more in depth, and may have arisen yet a third time in Lake Victoria if the enigmatic Paralabidochromis victoriae Greenwood is, indeed, a representative of that lake's species flock and not simply a miscataloged specimen from Lake Malawi. Interestingly enough, I know of no extralacustrine cichlids from either the Old or the New World with this sort of dental specialization. In Africa, the only riverine biotypes likely to offer comparable feeding opportunities are rocky rapids. Here one finds representatives of the mochokid catfish genus Chiloglanis using an essentially identical buccal dentition to selectively feed upon insect larvae. Chiloglanis are further modified for life in the rapids in possessing a sucker-disk oral apparatus analogous to that of the more familiar South American loricariid catfishes, a rudimentary swim bladder and a dorsoventrally flattened body, all adaptations that facilitate holding position in a strong current. I would suggest that the prior occurrence of better equipped competitors probably explains the absence of Labidochromis like representatives among the cichlids that have successfully colonized such habitats. There are no comparable assemblages of rapids-living cichlids in South America, a situation which, again, may be due to their exclusion from such habitats by better adapted siluroid or characoid colonists. In Central America and México, to the contrary, rapids-living cichlids do occur. While they include aquatic insects in their diet, they seem to make do quite well without the sort of dental specializations that characterize either their distant African lacustrine cousins or Chiloglanis.

The genus Labidochromis was believed to be monotypic until Fryer (1956) described a second species from Nkata Bay on the western shore of Lake Malawi. Since the establishment of a regular export business on the lake, the number of species referable to the genus has increased to an astonishing degree. To my certain knowledge, fourteen additional Labidochromis species have been collected and distributed through commercial channels since 1965. Five of these have been formally described: Labidochromis fryeri Oliver, Labidochromis mathotho Axelrod and Burgess, Labidochromis textilis Oliver, Labidochromis freibergi Johnson and Labidochromis exasperatus (Burgess). The remaining species are still awaiting formal description. This dramatic increase in the number of Labidochromis is really less surprising than it might seem at first. Labidochromis are small, secretive cichlids typically found in intimate association with rocky bottoms. Such highly petricolous fish are just the species short-term expeditions, relying upon traditional sampling techniques are likely to miss in their collecting efforts. It is the day in, day out activities of a commercial exporter that stand the best chance of turning up such secretive species. Additionally, the small size of these cichlids combines with their petricolous habits to sharply reduce their ability to disperse from one region of the lake to another. This situation encourages the evolution of distinctive localized populations which over a sufficient span of time can attain a degree of genetic isolation great enough to warrant their recognition as different species. The highly localized occurrence of such Labidochromis species as the Likoma Island Clown and L. caeruleus strongly suggests that the genus has been prone to such a pattern of microallopatric speciation within the Lake Malawi basin.

The appearance of additional Labidochromis species has entailed a reappraisal of one of the main characteristics used by Trewavas in defining the genus, the shape of the jaw teeth. The outer jaw teeth of L. vellicans are uniformly conical and, as this was the only species available to her, Trewavas was justified in making tooth shape an important element in the generic definition. It is now evident that there exist mbuna that agree with L. vellicans in other aspects of their jaw structure but whose jaw teeth comprise either a mixture of conical and unequally bicuspid or exclusively bicuspid teeth. The exclusively bicuspid outer jaw teeth of L. exasperatus were stated as the basis for its original description as a Melanochromis species (Burgess, 1976), a decision that reflected excessive reliance upon one morphological feature at the expense of an accurate diagnosis of the true relationships of the species in question. As I have pointed out in an earlier essay, the bicuspid dentition of L. exasperatus differs trenchantly in form from that of any Melanochromis (Loiselle, 1978b). Additionally, L. exasperatus lacks both the basic color pattern and the positive-negative sexual color differences characteristic of the genus Melanochromis. There are no grounds for retaining this colorful and very popular mbuna within Melanochromis and one can only hope that this erroneous classification will be expunged from the major reference works dealing with these cichlids (Axelrod and Burgess, 1978; Mayland, 1978).

Labidochromis differ considerably among themselves with regard to snout shape and body depth, as can be seen in the accompanying photographs. It is tempting to relate these differences to differences in feeding ecology, but the prevailing ignorance of the natural history of these fishes in Lake Malawi makes such speculation an essentially pointless exercise. It is worth mentioning that short-snouted Labidochromis are less tolerant of either conspecifics or other short-snouted species than they are of long-snouted congeners. While I have experienced few difficulties maintaining multiple male groups or harems of L. vellicans and L. textilis, it seems that even in tanks as large as 300 L, regardless of the number of fish I started with, the end result was a single pair of L. freibergi; or either Arabesque Fin Labidochromis. Not all mbuna fanciers have found this to be the case, so clearly there are other variables that operate to influence the sort of social system these mbuna wind up with in captivity. The novice, however, would still do well to bear this tendency in mind when acquiring these cichlids.

Housing these little mbuna poses few problems. Provided the aquarium is well furnished with refuges, Labidochromis do very well in the company of their larger relatives. They seem to fit in between the more aggressive Pseudotropheus and Melanochromis species on a day to day basis and manage to avoid confrontations during periods of sexual activity by holding breeding territories in secluded crannies too small to allow easy penetration by their larger companions. This is not to say they are in any sense timid or reclusive, for they are remarkably busy little cichlids that spend a great deal of time in the open. They just behave in a manner that does not elicit a great deal of attention from other mbuna. I suspect that they are simply acting in much the same fashion under these conditions of captivity that they normally do in Lake Malawi.

The lateral bars of this male Labidochromis textilis are an evanescent feature of the color pattern associated with aggressive behavior. This mainland species differs from its insular relative L. exasperatus in its silvery green base coloration, the absence of a black submarginal band in the dorsal fin and the details of its buccal dentition. Photo by Paul V. Loiselle.	This ovigerous female L. textilis nicely displays the narrow, pointed jaws characteristic of the genus. The intensity of the rusty longitudinal striping also displays considerable variability in L. textilis it is influenced strongly by the availability of necessary color precursor substances in the animal's diet. Photo by Paul V. Loiselle.
The color pattern of this male Labidochromis freibergi explains the common name of Dwarf Zebra frequently bestowed upon this most popular of Labidochromis species. Photo by Paul V. Loiselle.	The blue wash on the flanks of this female L. freibergi is characteristic of older individuals. It is the closest to masculinization of color pattern one will encounter in the genus Labidochromis. Photo by Paul V. Loiselle.
This undescribed Labidochromis species, sold under the common name of Likoma Island Clown, is the smallest known representative of the genus, as well as one of the most colorful. Exceptional males may attain 5.5 cm SL! Photo by Paul V. Loiselle.	Females of the Likoma Island Clown have the cranial and jaw morphology of their consorts but could hardly differ more in coloration. Photo by Paul V. Loiselle.

The great virtue of Labidochromis is their ability to prosper equally well in tanks in the 120-200 Lt range. The secret to success is, again, proper tank furnishings. Plenty of shelter is a prerequisite to success. I like to rest a thin slab of slab sandstone cut just a few centimeters smaller than the inside dimensions of the tank on a three-sided framework of PVC pipe, then pile fist to cantaloupe-sized rocks up to just below the water surface at each end of the aquarium. This arrangement combines a profusion of shelter with good water circulation. The fish appear to appreciate the open space in the center of the tank, while the rocky areas provide enough topological diversity to allow males to define and hold display territories quite easily. A 120 Lt aquarium so furnished will support a harem of one male and 6-8 female Labidochromis quite comfortably. Alternatively, it will support 3 or 4 pairs of as many different species. Nor need such a tank be limited to Labidochromis species. Any of the smaller mbuna will make suitable tank-mates for Labidrochromis. The various Cynotilapia seem to do quite well in their company, as does the Rusty Cichlid, Iodotropheus sprengerae. Paradoxically, one often finds that Labidochromis are much more inclined to hide when given a tank of their own than when housed in a community situation. The use of appropriate dither fish (Loiselle, 1979a) usually brings the cichlids out of the rock work in a short time. Bear in mind when selecting dither fish for their tank that Labidochromis are not efficient piscivores and cannot be counted upon to limit the reproductive output of poeciliids to any significant degree.

The maintenance requirements of Labidochromis do not differ in essential features from those of other mbuna species (Vide Crout, 1978). It is worth emphasizing that the management of the nitrogen cycle requires more attention in a 120 Lt aquarium than it does in one of 300 Lt capacity. An easily cleaned, reliable outside power filter charged with an efficient reusable medium such as Eheim's EHFIFIX^© and used in conjunction with a regular program of 30%-50% water changes represents the simplest management option available to the mbuna fancier. I emphasize that the unit should be easily cleaned because the effectiveness of a mechanical filter as a tool in the management of the nitrogen cycle is a function of how frequently entrapped organic wastes are removed from the unit. Little is accomplished by removing solid waste from the aquarium if it is allowed to undergo bacterial degradation in the filter unit. A filter that cannot be easily changed will not be frequently changed; a filter that is not frequently changed is not doing its job. There is no operational objection to using a combination of biological and chemical filtration in an mbuna tank, but these metabolically active cichlids impose a severe strain on the best chemically active media that dictates their frequent regeneration or replacement if the system is to function as it should. Most aquarists simply do not find the benefits of such a system vis-a-vis the combination of mechanical filtration and partial water changes sufficiently great to justify its greater cost.

Like all mbuna, Labidochromis are heavy eaters with catholic tastes. Any of the usual live or prepared foods are eagerly accepted and, with the exception of Tubifex worms, appear equally acceptable. There is, in my experience, a strong correlation between a steady diet of Tubifex worms and the onset of systemic bacterial infections such as the dreaded "Malawai bloat" in mbuna. Given how omnivorous these cichlids are, I see little justification for exposing them to any increased risk of disease by feeding them Tubifex. The coloration of all mbuna benefits if the fish have access to foods rich in precursor substances. Any of the flake foods billed as color enhancers are acceptable in this regard. So is finely chopped frozen zooplankton or a suitably compounded prepared food such as Berkeley "fish fudge" (Barlow and Cappetto, 1974). Like most small cichlids, Labidochromis do best if given several small meals rather than one large feeding daily.

Assuming both sexes are present in a properly furnished aquarium, Labidochromis will breed whether their keeper wants them to or not. While males are not as exuberant in their courtship as are some of their larger relatives, injury to an unresponsive female will occur unless there is plenty of cover for her and other fish present to distract her suitor. A harem arrangement suggests itself immediately, but a female also runs little risk if she and her consort share a tank with an assemblage of other mbuna. Males appear to have a strong preference for making a cave, or rock, crevice the focal point of their territory. Most of their courtship seems aimed at enticing or coercing the ripe female to enter its boundaries. As her eggs ripen, the female's reluctance declines dramatically and the appearance of a short ovipositor comprises a reliable indication that spawning will occur within the next 24 hours. The mechanics of spawning follow the general mbuna pattern. After an interval of very active display by the male, both fish engage in a period of reciprocal circling and vent-nudging that leads up to oviposition. The female picks up the eggs as soon as they are deposited, then re-initiates the circling pattern by butting and snapping at the male's vent. This presumably elicits ejaculation of sperm, which is then taken into the female's mouth where fertilization actually occurs. The whole process can be completed in as few as 15 minutes, but if the male is required to chase away intruders, spawning can take up to 2 hours.

The female leaves the male's territory once spawning is over. She is often harrassed by her erstwhile consort, and must have some sort of refuge from his attentions if she is to avoid injury and her keeper the loss of a brood. The male usually loses interest in a few days, sooner if other conspecific females are present. After a brief period of initial seclusion, ovigerous females are no more secretive than those of other mbuna, and swim quite freely in the open. They will also give inexperienced aquarists a nasty jolt by joining their tankmates at feeding time. Ovigerous females of the six Labidochromis I have bred all fed regularly while carrying. The quantity of food taken was small - no more than one or two adult Artemia or flakes of prepared food at a sitting. But it was clearly masticated in the pharyngeal region and swallowed, not expelled via the opercular slits. Such feeding is not obligate, as I have maintained females in isolation without access to food with no deviation from the species typical brooding behavior. Nor are there any data on its occurrence in nature.

Female Labidochromis are exceptionally competent mothers. A young female, regardless of whether she is moved to a separate nursery tank or allowed to carry in the aquarium where spawning occurred, may lose her first brood as may a reproductively experienced female who has been moved to new quarters. These are the only instances in my experience where a female Labidochromis will not complete the normal incubation sequence. Indeed, ovigerous females appear to be remarkably unselective about what they will brood. When these mbuna are maintained over a gravel bottom, it is not at all uncommon to find four or five pieces of gravel, about the same size and color as a Labidochromis egg tucked away in the buccal cavity along with mobile fry at the end of the incubation period. As the moment of fry release approaches, this broodiness appears to increase. Females will capture live Artemia and carry them for up to 48 hours in their buccal cavities along with their fry. They will also accept fry of other mouthbrooding species. I discovered this as the result of housing ovigerous females of Geophagus steindachneri and L. vellicans on either side of a 20 Lt aquarium divided by a screen partition. I calculated both females were due to release within 24 hours of one another, so I kept them under careful observation as their times grew near. A few days before the appearance of the fry was due, I noticed that the bulging throat of the female G. steindachneri was growing flatter, while that of her neighbor seemed to be swelling. This trend continued until by the projected release date, the female eartheater hardly seemed to be carrying at all, while the female Labidochromis looked as if she had tried to swallow a plum pit. The mystery was solved when both females were induced to part with their broods. The female G. steindachneri was found to be carrying a half a dozen fry, but the female L. vellicans released nineteen of her own progeny, plus 27 Geophagus fry and four pieces of gravel! I had apparently miscalculated the release date for the female eartheater, who had been releasing her mobile offspring to forage several days ahead of their anticipated appearance. As they wandered through the meshes of the barrier, the fry were apparently snapped up by the female Labidochromis, who then refused to let them go!

This undescribed Labidochromis species was also originally sold under the erroneous name Pseudotropheus minutus. The enlarged anteromedian teeth of the upper jaw are evident in this "Yawning" male Arabesque Fin Labidochromis. Photo by Paul V. Loiselle.	The intricate pattern of black markings in the caudal fn of this female Arabesque Fin Labidochromis explains the common name usually bestowed upon this species. Note that well developed psuedo-ocelli are present on the anal fins of both sexes in this species. This reduces their value as secondary sexual characteristics readily accessible to the aquarist. Photo by Paul V. Loiselle.
This striking Labidochromis species greatly resembles the Arabesque Fin as a juvenile. Adult males, however, have a darker breeding coloration than the forgoing species. Photo by Paul V. Loiselle.	The overall golden beige base color of juveniles and females of this species has earned it the designation of Honey Arabesque Labidochromis in some quarters, though as can be seen from this photograph of an adult female, the dark pattern in the caudal fm grows less elaborate with age. Photo by Paul V. Loiselle.
The distinctive cranial morphology of this attractive Labidochromis species has earned it the common name Horse faced Labidochromis. Photo by Paul V. Loiselle.	While the cranial morphology and color pattern of this female horse faced Labidochromis are reminiscent of the two Arabesque Fin species, other aspects of the male color pattern suggest a relationship between this species and representatives of the L. exasperatus group. Photo by Paul V. Loiselle.

The normal incubation sequence in these and other mbuna is 21 days at 29°C. In a community tank, female Labidochromis appear to release their fry one at a time over a period of one or two days. Judging from the behavior of females allowed to incubate in isolation, the fry, once released, are not taken back into the female's mouth. This absence of post release brood care sets Labidochromis apart from the other mbuna bred to date in captivity. Possibly because fry release is a one-shot proposition, female Labidochromis are often very reluctant to allow their fry to leave the shelter of the buccal cavity. This can lead to serious difficulty if the fry are precluded from foraging after they have exhausted the food reserves contained in their yolk sacs. Separating mother and fry is in order at this point, but this operation is complicated by the small size of the mouth a Labidochromis species. However, there is a simple technique that forces female mouthbrooders to expell their fry with a minimum of trauma to mother and offspring. Fill a one or two liter container with water from the female's aquarium. Remove the squeeze bulb from a clean oven baster and place it narrow end down in the container of water. Catch the laden female and slip her head down into the baster. The small adult size of female Labidochromis makes this easier to do than it sounds. Now, without disturbing position of the baster, replace the squeeze bulb. Squeezing the bulb forces water back and forth through the female's mouth and gill chambers. In conjunction with the female's normal respiratory movements, this usually serves to flush the fry out of her mouth. If several minutes of this treatment fail to produce the desired result, remove the baster from the water for 30 to 60 seconds, then return it to the container and repeat the procedure. Once all the fry have been obtained, the female can be returned to her tank, with minimal injury to anything but her dignity.

Compared to other mbuna, Labidochromis are not very prolific. Though I have heard of exceptionally large females releasing up to 60 fry, in my experience a brood of 35 fry is a large one, with the mode ranging between 20 and 25 eggs/spawning. As the eggs of these cichlids measure c. 3.0 mm along their major axis, such small spawns are not to be wondered at in cichlids having such small mouths and buccal cavities. By way of compensation, the fry make up in quality what they lack in quantity. Their size at release varies from 9.0-10.0 mm TL for the smaller species such as L. freibergi and the Likoma Island Clown to 15.0 mm TL for larger species such as L. textilis. They are extremely robust and have no difficulty handling either Artemia nauplii or finely divided prepared foods for their initial meal. With heavy feeding and frequent partial water changes, the fry of most species will measure 2.0 cm-2.5 cm SL by their eights week post release. Sexual maturity is attained between the sixth and eighth month post release.

If the fry survival rate in captivity under community tank conditions is any indication of its efficacy in nature, there is quite a bit to be said for the strategy of producing few, large, very well developed fry rather than large numbers of smaller ones. The aquarist interested in simply rearing enough fry to replace his original breeders and trade with fellow hobbyists need do no more than provide plenty of shelter in the community tank and start feeding brine shrimp nauplii when the first fry appear among the rocks. Some fry from each spawning effort will escape the attentions of their tankmates and grow to maturity without any additional attention on their keeper's part. In one instance I observed the spawning of a pair of L. freibergi from start to finish, which provided the necessary baseline to calculate the fate of fry survival. Eleven out of twenty-seven fry survived to sexual maturity in a 300 Lt tank stocked with an assortment of Pseudotropheus and Labidochromis species, a pretty impressive performance even if one allows for the fact that most mbuna are fairly inefficient piscivores.

Despite the combination of small adult size, brilliant male coloration and generally unaggressive temperament, Labidochromis are not always easy to find through commercial channels. Their relatively low fecundity and slow growth to marketable size limit the appeal of Labidochromis to large-scale breeders. The best way to track down these extremely desirable mbuna is through the Trading Post of the American Cichlid Association, which is equally effective as a means of meeting fellow hobbyists with similar interests. So, if space limitations prevent you from moving a 400 Lt. aquarium into your house, don't deprive yourself of the pleasure of a mbuna tank. Take the time to chase down some of these sparkling little gems. I guarantee you'll find them well worth the effort.

References

• Crout, J. R. 1978. The mbuna group of cichlids from East Africa. F.A.M.A. /(7):14-17 et seq.

This article was originally published in Freshwater And Marine Aquarium Jul-80 pp. 15-20, 80-85, It is reproduced here with the permission of author Paul V. Loiselle).