Congochromis sabinae (LAMBOJ, 2005)

Classification

Order: Perciformes Family: Cichlidae

Distribution

Described from the Loubi River, a tributary of the Likoula River in northeastern Congo (Brazzaville) which is itself part of the enormous Congo river system. It’s also been recorded from other central and northern parts of the country west of the Upper Congo basin as well as in northeast Gabon (Ogooué River) and northern DR Congo near the settlements of Genema and Bamanya (Bondele River).

Fish entering the trade are often labeled with apparent collection locality e.g. ‘Tschuapa’ but such details aren’t always accurate and should be regarded with caution.

Habitat

At the type locality the Loubi River was just 2-3 metres in width and shallow with a maximum depth of 1.2 metres. The area through which it flows was forested with thick marginal vegetation overhanging, and thus shading, the water in places.

The water itself was stained reddish brown with tannins released by decaying organic material, conductivity was 40 µS, pH 4.0 and temperature 75.2 – 77°F/24 – 25°C. Other locality data is broadly similar with the species apparently showing a preference for rainforest streams and tributaries.

Maximum Standard Length

Males can reach 65 – 70 mm with females a little smaller at 45 – 50 mm.

Aquarium SizeTop ↑

An aquarium base measuring 60 ∗ 30 cm or similar should be the minimum considered for both breeding and general maintenance purposes, with significantly larger quarters required if more than a single pair is to be housed together.

Maintenance

Use a soft, sandy substrate since this species is mostly benthic and provide caves/potential spawningsites by placing a few driftwood roots and branches placed in such a way that plenty of shady spots are formed and/or adding clay flowerpots, halved coconut shells, etc. Some hobbyists add lengths of plastic piping of a suitable diameter to provide cover and potential spawning sites.

The addition of dried leaf litter (beech, oak or Ketapang almond leaves are all suitable and a mixture of all three can look very effective) would further emphasise the natural feel and not only provide additional cover but facilitate development of microbe colonies as decomposition occurs. Such microfauna can provide a valuable food source for fry while the tannins and other chemicals released by decaying leaves are thought beneficial for blackwater fish species.

Fairly dim lighting is preferable. You could add some aquatic plants that can survive under such conditions such as Anubias, Microsorum, Taxiphyllum or perhaps some potted Cryptocoryne spp. A few patches of floating vegetation to diffuse the light entering the tank would also be useful, while gentle filtration providing a little surface agitation is adequate. Congochromis spp. require stable water conditions and should never be introduced to immature aquaria.

Water Conditions

Temperature: 24 – 27 °C

pH: 4.0 – 6.0

Hardness: 0 – 54 ppm

Diet

Congochromis spp. are benthic detrivores mostly feeding on plant material and other organic detritus though some aquatic invertebrates are undoubtedly taken as well. In captivity the diet should therefore comprise a variety of quality, fine-grade prepared foods containing high proportions of Spirulina or equivalent.

Some live and/or frozen chironomid larvae (bloodworm), Daphnia, Artemia, mosquito larvae, etc. can be offered on an irregular basis. Home-made, gelatine-bound recipes containing a mixture of dried fish food, puréed shellfish plus fresh fruit and vegetables are proven to work well and can be cut into bite-sized pieces using the end of a sharp pipette or small knife.

Behaviour and CompatibilityTop ↑

Can be maintained in a community provided tankmates are properly researched and chosen with care. Good choices include diminutive, pelagic, schooling species such as Ladigesia roloffi or Lepidarchus adonis plus smaller ‘Barbus‘ and Aplocheilichthys killifishes.

It can also be kept alongside many peaceful South American characins, Otocinclus or smaller Corydoras catfishes and Southeast Asian cyprinids like Trigonostigma or Boraras species. Other cichlids are best avoided unless the tank is very big, and larger, substrate-dwelling species should be omitted entirely in order to avoid excessive competition for territory and food.

For breeding purposes C. sabinae is best kept alone or with a group of small-mouthed, non-predatory ‘dither’ fish such as Nannostomus spp. Though not especially aggressive compared with some related fishes, Congochromis spp. are non-gregarious and males are territorial so it’s best just to keep a single pair in most tanks, though in larger aquaria a group may coexist.

Sexual Dimorphism

In adult males the posterior half of dorsal fin has a white margin with an additional, thin, red submarginal band in some specimens. The anterior portion of the dorsal fin is pale reddish brown with the posterior part a more intense orange to reddish brown with small, reddish and pale blue spots. The caudal fin is clear to hyaline with 6-8 rows of red to reddish-brown and pale blue spots, these usually pale or absent distally in the lower lobe.

The posterior part of the upper lobe has a thin, white marginal band and a broader, red submarginal band in some individuals. The anal fin is bluish to violet with rows of red and pale blue spots and a dark violet to black distal margin. The anterior margin of the pelvic fins is whitish, with the rest of the fin pale reddish to pale violet. The pectorals may be clear to pale orange, and the body scales have greyish margins. The opercle, throat and ventral parts of the flanks and chest are reddish to orange, this intensifying inbreeding individuals.

In females the dorsal fin has a thin black to greyish marginal band and a white to silvery submargin. The remainder of the fin is orange to reddish with pale blotches and/or small black spots in some specimens. The caudal fin is pale orange to red, this being more intense in the upper lobe. The anal fin is clear to yellowish, the pectoral fins pale yellow to pale orange and the pelvic fins orange to violet with a pale anterior margin.

The mouthparts, cheek and opercles are orange to red. Sexually mature, gravid individuals exhibit a pinkish flush to the flanks and and belly between the pectoral and anal fins, this becoming darker when actively courting, and the dorsal surface is often flushed with orange. There is a patch of 2-3 silvery scales around the genital papilla on each side of the fish.

Reproduction

Congochromis spp. are monogamous, bi-parental cave spawners and spawn readily in aquaria provided their basic needs are met. Although adults can survive in slightly hard water successful egg/embryo development only occurs under conditions of little-to-no detectable hardness so this should be the primary concern with use of a reverse osmosis unit necessary in many cases. Otherwise the tank can be set up as described above with filtration best provided by an air-powered sponge unit set to turn over gently.

Pairing is relatively easy and if adult specimens are available simply placing a male and female together in the spawning tank is often sufficient. The former may chase the latter in the initial stages but physical damage is unreported as far as we know. If starting with a group of juveniles or subadults be prepared to split them once a pair forms.

Courtship is initiated by the female and once in condition she will begin to exhibit brood colouration and display to her potential partner by bending her body into a ‘U’ shape, thus presenting the now intense violet belly region to him, while quivering rapidly. Receptive males also take on different patterning with more intense red to orange pigmentation in the lower, anterior portion of the body, and in both sexes the overall body colouration pales with the dark lateral stripe fading somewhat. Eventually a concealed spawning site will be selected to which the pair usually excavate their own entrance.

Once the eggs are laid and fertilised the female remains in the cave and is solely reponsible for broodcare while the male is ejected and defends the surrounding territory. The incubation period is temperature-dependant to an extent but normally around three days after which the fry tend to be hung from the roof of the cave until free swimming, around 8-9 days post-spawning.

They’re large enough to accept Artemia nauplii once visibly foraging outside the cave though other invertebrates such as micro or banana worms, Cyclops, Daphnia, etc. are also accepted. Parental care is well-developed and continues for 5-6 weeks although in some younger/inexperienced pairs the male may become territorial towards the female, necessitating her removal.

NotesTop ↑

This species was present in the hobby for some time prior to being officially described and the spectacular red fish first exported by Pierre Brichard in the 1960s appears to be a regional form of it. It was also known variously as Nanochromis sp. ‘Bamanja’, N. sp. ‘Genema’, N.sp. ‘Makoua’ and N. sp. Bloody Mary’ prior to description, and continues to be mislabelled as N. squamiceps on trade lists.

Diagnosis of C. sabinae is possible via a combination of characters as follows: body moderately elongate; relatively abrupt, rounded head profile: rounded snout; rounded caudal fin; presence of one tubular infraorbital bone; nape and opercle scaled; one or two scale rows on posterior part of cheek; females with a few silvery scales around the genital papilla; black lateral body stripe, not extending into caudal fin.

It differs from the congeners C. dimidiatus and C. squamiceps in a number of aspects of including shorter head length, greater head depth, greater preorbital length (and thus a more robust, rounded forehead and snout), shorter caudal peduncle, higher number of gill rakers on the first arch and colour pattern e.g. the dark midlateral stripe doesn’t extend into the caudal fin whereas it does so in the other two. C. pugnatus, the only other described species, lacks the midlateral stripe altogether so is readily told apart.

Additionally, the white and red submarginal bands present in the upper caudal fin lobe of male C. sabinae are missing in C. dimidiatus, while females of C. dimidiatus and C. pugnatus do not possess a small patch of silvery scales around the genital papilla. Conversely, females of C. squamiceps have a broad band of such scales extending vertically from the genital region to midbody while those of an undescribed species usually traded as C. sp. ‘green speckle’ (sometimes mislabelled C. sabinae) have a similarly-positioned but thinner band.

Some Congochromis spp. were previously included in Nanochromis which was erected by Pellegrin (1904) with the chief distinguishing feature an extremely elevated upper lateral line. However the the older members, C. dimidiatus and C. squamiceps, had been considered to represent one of two distinct groupings within that genus since the phylogenetic analysis of Greenwood (1987).

They were separated from other Nanochromis spp. by a suite of characters including: 3-5 (less than half) of pored upper lateral line scales contiguous with dorsal fin base (vs. posterior half, or more than half, of pored upper lateral line scales contiguous with dorsal fin base); belly and nape completely scaled (vs. nape scaleless); chest and cheek partially scaled (vs. chest and cheek scaleless); presence of a single, reduced, comma-shaped supraneural bone (vs. supraneural bone absent in most specimens); possession of a dark midlateral body stripe (vs. absence).

These mini-assemblages were subsequently referred to as ‘Group 1’ and ‘Group 2’ (Lamboj, 2004) or the ‘nudiceps‘ and ‘squamiceps‘ groups (Schliewen and Stiassny, 2006), with new species being described in both during the mid-2000s. Later Stiassny et al. 2007 elected to formally move members of ‘Group 2/squamiceps group’ into the new genus Congochromis based on the characters listed above, plus possession of widely spaced, relatively robust, unicuspid jaw teeth (vs. extremely fine, closely spaced, unicuspid jaw teeth in Nanochomis spp.).

Congochromis is also diagnosable by some internal features comprising presence of four laterosensory pores on the dentary, absence of a tubular pore canal in the anguloarticular and possession of six laterosensory pores on the preopercle. There currently exist five described species plus a handful awaiting description, some of which have already been seen in the hobby.

Within the family Cichlidae Congochromis is a member of the informally-recognised chromidotilapiine clade and is most closely-related to Nanochromis. Unpublished DNA analyses mentioned by Stiassny and Schliewen (2007) also placed Chromidotilapia schoutedeni (Poll and Thys van den Audenaerde, 1967) and Limbochromis robertsi (Thys van den Audenaerde and Loiselle, 1971) as sister species. These were unexpected results and further work is in progress to more fully understand the relationships between members of this clade.

References

1. Lamboj, A., 2005 - Zootaxa 827: 1-11
   Nanochromis sabinae, a new cichlid species (Teleostei, Cichlidae) from the Upper Congo River area and northeast Gabon.
2. Lamboj, A., 2004 - Birgit Schmettkamp Verlag: 1-256
   The Cichlid Fishes of Western Africa.
3. Stiassny, M. L. J. and U. K. Schliewen, 2007 - American Museum Novitates 3576: 1-14
   Congochromis, a new cichlid genus (Teleostei: Cichlidae) from central Africa, with the description of a new species from the upper Congo River, Democratic Republic of Congo.