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by Paul Loiselle |
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The excitement of working with newly introduced species is one of the more engaging aspects of the aquarium hobby. It is unfortunate that the drive to keep and breed the latest new additions to the ranks of aquarium fish often results in the neglect or even the disappearance of species that by any objective criteria merit a different fate.
While they have tremendously enlarged the pool of competent amateur fish breeders, the breeder’s award programs mounted by aquarium societies three decades ago have exacerbated this problem. Some clubs have always included a species maintenance component in their breeder’s award programs and the C.A.R.E.S. program now provides an institutional framework for the long-term captive maintenance of a wide variety of aquarium fish. The importance of such a program cannot be over-emphasized. Fifty years ago one could reasonably expect that a species lost to the hobby could be re-established by a fresh importation of wild-caught founders. This is no longer a realistic assumption. Freshwater fish are under increasing threat from climate change, unsustainable land use practices, and invasive exotics. In the case of a number of Lake Victoria haplochromines that made their aquarium debut in the 1980’s, re-introduction is precluded by their extinction. In the case of many other species, the obstacle to their re-introduction has less to do with their conservation status than with the political instability of their range states. I would like to devote this article to a suite of colorful and easily maintained species that I have had the pleasure of keeping and breeding over the past four decades but that are no longer available to contemporary cichlid enthusiasts. With one possible exception, these fish do not, to the best of my knowledge, face any immediate threats to their near-term survival. As their habitats are more or less readily accessible to established tropical fish exporters, the only obstacle to their re-introduction to the hobby is the lack of commercial demand. Hopefully this article will generate sufficient interest among its readers to stimulate their re-importation while such an exercise is still feasible. | |
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Erroneously identified as Haplochromis wingatii, the first of these species made its scientific debut in the paper that elucidated the function of the pseudo-ocelli present on the anal fins of haplochromine cichlids (Wickler,1962). According to Fishes of Burundi’s André Schreyen (pers. com.), this species was probably included in the shipments of Astatotilapia burtoni made to Europe from the Lake Tanganyika basin in the late 1950s. I encountered this species in 1972 and was immediately taken by the striking coloration of breeding males, strongly reminiscent of that of the Lake Victoria basin’s Astatotilapia nubila. My conclusion that the fish could not be H. wingatii was supported by the late Humphrey Greenwood, to whom I sent color photos of both a sexually quiescent and a breeding male. Greenwood (pers. com.) recognized the fish as an undescribed representative of the Haplochromis bloyeti complex he had encountered many years previously in the Malagarasi drainage. He suggested in the absence of a precise locality of origin, the fish was best referred to as Haplochromis bloyeti “Burundi” pending its formal description, a usage to which I gladly subscribed. With the subsequent re-definition of the genus Haplochromis (Greenwood, 1979), the generic placement of this species changed, obliging me to re-label my slides as Astatotilapia bloyeti “Burundi”. The question of its generic placement had by then become moot, as the fish was no longer to be had. In the absence of accurate locality data, the re-importation of this very attractive haplochromine, however desirable, seemed unlikely in the extreme. I was therefore very pleasantly surprised to encounter both a color photograph and a precise collecting locality for this species in a monograph dealing with the fishes of the Lake Rukwa basin (Seegers, 1996a). Seegers found this fish in the Moyowosi River, a northern tributary of the Malagarasi whose source lies in eastern Burundi. It entailed a twenty-five year wait, but at last I could relate my images of this fish to a definite locality! More to the point, it is now possible to point the Fishes of Burundi team at a specific collecting site. | |
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It should also be a relatively simple matter to arrange for the re-importation of Astatoreochromis vanderhorsti (Greenwood 1954) the second of my septet of “heritage haplochromines”. This colorful species is a commonly encountered resident of the Malagasi drainage, to which it is endemic. As the upper reaches of the Malagarasi River constitute the border between Burundi and Tanzania, suitable collecting sites for A. vanderhorsti are located a relatively short drive eastward from Bujumbura. This species made its aquaristic debut in the late 1970s. While it initially enjoyed a modest degree of popularity, it had become increasingly hard to find by the time it was profiled in the American Cichlid Association’s Cichlid Index (Johnson & Loiselle, 1977). A similar trajectory has characterized the history of the Lake Victoria system’s Astatoreochromis alluaudi in the hobby. Its large adult size and decidedly peppery disposition go far towards explaining why A. alluaudi has not enjoyed a great deal of commercial success (Smith, 2001). However, as A. vanderhorsti is burdened by neither of those shortcomings, other factors must be invoked to account for its failure to win a permanent place in the ranks of ornamental fishes. I suspect that like the Lake Victoria haplochromines that made their debut at about the same time, A. vanderhorsti was a victim of what I have come to think of as the “Malawi tsunami”. While that lake’s endemic haplochromines are not necessarily more colorful than their distant Victorian or riverine relatives, their color patterns tend to be more behaviorally invariant under aquarium conditions. While the male breeding dress of Victorian—and many riverine—haplochromines is the equal to that of any group of freshwater fishes, the color pattern of sexually quiescent individuals is often, to put it tactfully, understated. In contrast, that of Malawian haplochromines, once turned on, typically stays that way under aquarium conditions. The commercial success of many of Lake Tanganyika’s cichlids demonstrates that a species need not be flamboyantly colored to be a commercial success, but there is no denying that consistently eye-popping coloration certainly helps! The attractive juvenile coloration—and consequent high marketability—of many mbuna species also goes far towards explaining why Florida fish farmers have been so willing to devote pond space to their production. | |
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My next trio of “heritage haplochromines” hails from Malawi. However, they are not found in Lake Malawi but rather inhabit Lakes Chilwa and Chiuta. These two shallow lakes lie in a basin situated south-east of Lake Malawi on the border between Malawi and Mozambique. Located 50 miles (c. 83 km) from the southernmost point of Lake Malawi, Lake Chilwa has neither an outlet nor major rivers draining into it. The neighboring Lake Chiuta is bisected by the border between the two countries. It is intermittently connected with Lake Chilwa across an extensive swamp and drains into the eastward flowing Rovuma River in Mozambique. As Lake Chilwa’s surface area and maximum depth thus depend upon rainfall, both can vary dramatically from one year to the next. When rainfall is at a maximum extent, Lake Chilwa measures 36 miles (60 km) long and 24 miles (40 km) wide, with a average depth of 10 feet (3 m). In periods of drought, it dries up completely. Were it not for the refuge offered by persistent springs within its catchment, Lake Chilwa’s fish fauna would be limited to lungfish and annual killies. In reality, during high water years, Lake Chilwa supports an important commercial fishery that exploits its most abundant cichlid, a subspecies of Oreochromis shiranus. In a good year, the Lake Chilwa fishery yields 24 000 metric tons of fish, roughly 20% of Malawi’s total catch. In 1972, importers in the Los Angeles area received several shipments of cichlid fish from the Chilwa-Chiuta system. The shipment included Tilapia rendalli, Oreochromis s. chilwae, and three haplochromines. The smallest of these was a Pseudocrenilabrus species whose coloration was more reminiscent of Pseudocrenilabrus victoriae and riverine Pseudocrenilabrus populations from Zambia (Katongo et al., 2005) than that of the population of P. philander previously exported from the Lake Malawi basin. The other two were distinctive species now placed in the genus Astatotilapia. One of these, which was marketed as a Labidochromis species, I erroneously identified as Haplochromis acuticeps (Loiselle, 1974). It was subsequently described as a new species and named Astatotilapia tweddlei by Jackson in 1985. The second was exported and marketed as Haplochromis callipterus, an attribution which was generally accepted at the time. Recently published research (Domino et al., 2011) has shown that this species differs genetically from all of the numerous nominal Malawian A. calliptera included in their study displaying instead closer affinities to Astatotilapia species from the Rovuma and other coastal rivers in Mozambique. | |
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I successfully bred all three species. I distributed fry to friends in the Los Angeles area when I closed down my tanks preparatory to moving to Berkeley to start my graduate work. However, I made no further effort to assure their persistence in the hobby. In retrospect, I have come to regret this oversight. While the coloration of A. tweddlei is unlikely to excite the interest of most cichlid enthusiasts, Lake Chilwa’s other two hapochromines are, if I may be forgiven the phrase, quite another kettle of fish! While the lake’s distinctive Pseudocrenilabrus shares the decidedly bellicose disposition of its congeners, it is one of the smallest representatives of the genus I have ever encountered, males growing no larger than 2 inches (c. 5.0 cm) TL. Its diminutive size makes it relatively easy to manage its behavior in captivity and its striking golden yellow coloration makes the effort well worthwhile. The jade green base color of Astatotilapia sp. ‘Chilwa’ is unique among the riverine Astatotilapia species to date imported and its intensity puts to shame the several Victorian haplochromines whose color pattern features orange and green. This Lake Chilwa endemic is easily the most colorful known representative of the A. calliptera species group and would well repay the efforts of Florida fish farmers to put it into commercial production.
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While Lake Chilwa is a fair distance from the late Stuart Grant’s facility, it is by no means inaccessible. The lake is about 50 miles from Zomba, Malawi’s second largest city. As the lake supports a major fishery whose output is regularly transported to the rest of the country, it enjoys reasonable vehicular access. Given sufficient market demand, it should be possible to arrange for the collection and re-exportation of these three cichlids without a great deal of difficulty. It would be prudent to undertake such a project as soon as possible. Lake Chilwa is presently entering a period of contraction sufficiently pronounced to provoke a sense of alarm over the effect the possible loss of its fishery would have on Malawi’s economy (Mkoka, 2012 ). Fifty years ago, this would not have been a cause for conservation concern, for as already noted, its native cichlids have rebounded from the lake’s complete dessication in the recent past. However, in an era of progressively more extreme weather events, it may not be wise to assume that this pattern will inevitably continue to repeat itself.
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Until relatively recently, there was great uncertainty over the provenance of my next “heritage haplochromine”. This fish apparently made its North American aquarium debut in the late 1960s. Marketed as Haplochromis Black and Gold, it was clearly a Pseudocrenilabrus species, notwithstanding the fact that the anal fins of adult males lacked the distally placed red terminal spot characteristic of other species of the genus. It was said to hail from somewhere in the Congo River system. As the Congo basin covers an area about as large as western Europe, didn’t do much to specify this species’ actual point of origin! In a well illustrated review of the genus Pseudocrenilabrus, Seegers (1996b) published a photograph of an adult male of this species, which he identified as representative of a population of putative P. philander native to the Lufira River, a tributary of the Congo River situated in the Democratic Republic of the Congo’s Shaba—formerly known as Katanga—Province. I initially thought this species to be Pseudocrenilabrus ventralis (Nichols 1928). However, P. ventralis proved to be a junior synonym of Pseudocrenilabrus nicholsi (Pellegrin 1928), another very differently colored species native to the southern Congo basin. This species was widely available on the West Coast of the United States well into the 1970s. In light of its extremely striking coloration, ease of maintenance and reproductive precocity, the persistence of Pseudocrenilabrus Black and Gold in the hobby appeared to be assured. It certainly seemed a natural candidate for commercial production in Florida. Yet by 1980, it had vanished from the North American aquarium scene. Seeger’s photograph is evidence that this species was also known to European hobbyists and appears to have been available in Germany as late as the mid-1990s. It appears to have since vanished from the aquarium scene there as well (O. Lucanus, pers. com.). Shaba is a long way from Kinshasa, capital of the Democratic Republic of the Congo and the base from which that country’s ornamental fish exporters operate. Logistic difficulties aside, the security situation in that region has been in the past somewhat questionable. However, Pseudocrenilabrus Black and Gold is not the only reason exporters might find it desirable to pay some attention to that part of the world. The recent discovery of a thirteen-species flock of Pseudocrenilabrus in Lake Mweru (Stelkens & Seehausen, 2009) emphasizes that the southern tributaries of the Congo are still very much virgin territory as far as the ornamental fish trade is concerned. | |
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There is no ambiguity at all about the provenance of the last member of my septet of “heritage haplochromines”. This species was introduced to the aquarium hobby by Herbert R. Axelrod, who collected it from a spring outside of the city of Kano, Nigeria (Axelrod, 1958). This certitude did not extend to its identity. It was one of the several species to which the nomen Haplochromis wingatii was erroneously applied and it has been conflated with undescribed haplochromine cichlids collected in Lake Debo, a floodplain lake of the Niger system situated in Mali and from Lake Chad. In point of fact, the Nigerian Mouthbrooder, to give the fish its vernacular name, is an Astatotilapia species, while the former Haplochromis wingatii is the type species of the genus Thoracochromis. It also differs significantly from the Lake Debo and Lake Chad haplochromines with respect to its overall morphology, lower pharyngeal dentition, and placement of anal fin pseudo-ocelli (Loiselle, 1975). The Nigerian Mouthbrooder is an undescribed Astatotilapia species that most closely resembles the yellow morph of the Lake Tanganyika basin’s A. burtoni. Whether this similarity reflects convergent evolution or the close phyletic affinity of these two species remains to be determined. Prior to the opening of Lake Malawi to the ornamental fish trade in the early 1960s, the Nigerian Mouthbrooder was one of the very few haplochromine cichlids available to hobbyists. While this species appeared on the price list of at least one Florida fish farm for several decades, it never attained a great deal of popularity. I was able to work with this species in the late 1970s. Through hybridization experiments I was able to determine that the Nigerian Mouthbrooder and A. burtoni were distinct species, crosses between the two producing unisexual broods. I made the mistake of waiting too long before rearing replacements for my breeders and lost the strain when those fish became reproductively senescent. I have not seen this species since. In the case of the Nigerian Mouthbrooder, I suggest that there is little mystery surrounding its disappearance. It was, quite simply, displaced by the very similar but more colorful yellow morph of A. burtoni. Northern Nigeria lies within Africa’s Sahel zone, a region that has undergone several severe droughts over the past half century. These droughts have significantly impacted aquatic habitats. The most obvious example of this phenomenon has been the dramatic contraction of Lake Chad. In light of how little is known of the natural history of the Nigerian Mouthbrooder, any evaluation of its conservation status must necessarily be less rigorously supported by data than one might wish. However, this species is known to occur in only a single locality situated in a region that has been negatively impacted by climate change in the recent past and that is very likely to be similarly afflicted in the future. In light of these facts, it is difficult to be very optimistic about its conservation status. A serious effort should therefore be made to ascertain the actual status of this species. Should it prove to have survived the droughts of the past fifty years, priority should be given to establishing secure captive populations as insurance against its global extinction. Given that Nigeria supports an export trade in ornamental fish, one might conclude that realizing such a project, while it might prove both costly and logistically challenging, is not completely unrealistic. Regrettably, the northern region of Nigeria has been and continues to be plagued by Boko Haram, a xenophobic Islamist insurgency. In light of the serious security issues caused by these terrorists, whose antipathy extends to both foreigners and non-Moslem Nigerians, traveling the countryside around the city of Kano in search of endangered fish is, at least for the present, extremely ill-advised. Thus for the moment, the best that the Nigerian Mouthbrooder’s advocates can hope for is that this species’ resilience allows it to survive until the security situation in northern Nigeria improves to the point where more active measures can be undertaken on its behalf. | |
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I would like to conclude this article by introducing cichlid enthusiasts to an Astatotilapia species that while not to date imported, well deserves the attention of Tanzanian exporters. I photographed this species in the aquarium of Tim Davenport, the head of the Wildlife Conservation Society’s Tanzania program when I visited that country in 2007. The fish were collected from a stream on Mt. Rungwe. The Rungwe Massif is a range of volcanic mountains in southwestern Tanzania that supports a number of crater lakes and whose streams flow into the northern end of Lake Malawi. Its existence is evidence that Astatotilapia species diversity within Lake Malawi’s catchment is both quite high and very incompletely surveyed. This species is certainly attractive enough to merit the interest of the Tanzania-based fish exporters, whose offerings include cichlids from both Lake Tanganyika and Lake Malawi. The road to Itungi, Tanzania’s principal port on Lake Malawi, passes immediately to the west of the Rungwe Massif and crosses a number of streams that rise on its slopes. If importers find its combination of striking coloration and ready accessibility as intriguing as I do, cichlid enthusiasts should not have to wait very long for the opportunity to work with Astatotilapia sp. ‘Rungwe’! This species is certainly attractive enough to capture the interest of commercial breeders in Florida. However, the existence of the C.A.R.E.S. program offers hope that even if it does not, Astatotilapia sp. ‘Rungwe’ can avoid the fate of the “heritage haplochromines” profiled herein. Axelrod, H. R., 1958. In Passing (Collecting in Kano, Nigeria). T.F.H. Magazine, 6(5): 7–22. Katongo, C., S. Koblmüller, N. Duftner, L. Makasa & C. Sturmbauer, 2005.Phylogeography and speciation in the Pseudocrenilabrus philander species complex in Zambian rivers. Hydrobiologia, 524: 221–233. Domino, J. A., D.H. Lunt, M.J. Genner, G.F. Turner, R. Bills, R. & O. Seehausen, 2011. Repeated colonization and hybridization in Lake Malawi cichlids. Current Biology, 21(3): 108–109. Greenwood, P. H., 1979. Towards a phyletic classification of the “genus” Haplochromis (Pisces, Cichlidae) and related taxa. Bull. Br. Mus. Nat. Hist.(Zoology), 35(4): 265–322. Johnson, D. & P.V. Loiselle. Haplochromis vanderhorsti Greenwood 1954. A.C.A. Cichid Index, 2(4): 1–3. Loiselle, P. V., 1974. The cichlid fishes of the Chilwa-Chiuta Depression. Part 2. Buntbarsche Bull., 45: 11–17. Loiselle, P. V., 1975. A review of the Haplochromis nomina commonly utilized by aquarists and the taxa to which they apply. Buntbarsche Bull., 49: 3–23. Mkoka, C., 2012. Malawi fears hunger as Lake Chilwa dries. Environmental News Service: http://ens-newswire.com/2012/08/24. Seegers, L., 1996a. The Fishes of the Lake Rukwa Drainage. Annales Mus. Roy. Afr. Centr. (Sciences Zoologiques), 278: 1–407. Seegers, L., 1996b. Die Gattung Pseudocrenilabrus. Kleine maulbrütende Cichliden aus Afrika. Das Aquarium, 327: 7–12. Stelkens, R.B. & O. Seehausen, 2009. Phenotypic divergence but not genetic distance predicts assortative mating among species of a cichlid fish radiation. J. Evol. Biol., 22(8): 1679–1694. Smith, M. P., 2001. Lake Victoria Basin Cichlids. Barron’s Educational Series, Hauppauge, pp. 1–95. Wickler, W. 1962. Zur Stammesgeschichte funktionel korrelierte Organ- und Verhaltensmerkmale: Ei-Attrapen und Maulbruten bei afrikanische Cichliden. Z. Tierpsychol., 19: 129–164. |
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