Lake Mweru Species Update

My experience with Lake Mweru species began in August 2018 when the NECA worked with Oliver Lucanus to bring in a shipment of fish from this lake. I was lucky enough to end up with groups of wild Serranochromis stappersi and Tilapia sparmannii from this initial shipment. With a subsequent shipment a couple months later I was also able to obtain additional wild groups which were named at the time as Serranochromis macrocephalus and Psuedocrenilabrus pyrrhocaudalis. With the Lake Mweru collections so new and the fish being worked with for the first time, it was not surprising to learn a bit later that Serranochromis microcephalus and Psudeocrenilabrus pyrrhocaudalis were in fact new species and were now designated Serranochromis sp. ‘Large Tooth Group’ and Psuedocrenilibrus sp. ‘Gray Back’ respectively. There were other Lake Mweru species in these initial collections including multiple variants of Psuedocrenilabrus, and there was also a more recent third collection which included even more species. For the time being, mostly due to available tank space, I have kept myself initially to the four species mentioned above.

Cichlid species from Tilapia, Serranochromis, Sargochromis, Orthochromis, and Psuedocrenilabrus are represented in the lake. While it was a fairly expensive opportunity, diving in heads first with the four Lake Mweru species was nonetheless one that I took advantage of without hesitation. Lake Mweru is located in the African rift valley roughly 150 miles west of the southern end of Lake Tanganyika and it is part of the Congo River system. The lake is fed by the Luapula and Kalungwishi Rivers and is drained by the Luvua River. Some key characteristics of the lake include a pH range of 6.4 to 9.3 and a temperature range of 70 - 84°F. While I currently keep my four species in separate and different sized tanks, all are kept at a pH between 7.5 and 8.0 and a temperature around 82°F. Each tank has CaribSea cichlid sand for a substrate, no plants, and a combination of medium sized rocks and terra cotta flower pots / cichlid caves for decorations. One tank, housing the Tilapia sparmannii, also has a couple medium sized ceramic logs I picked up from South Central Cichlids at the 2019 NECA-ACA Convention. All four tanks are filtered by multiple internal sponge filters, driven by the central blower system in my fish room. Additionally, a 110 gallon tank housing the S. sp. ‘Large Tooth Group’ and a 55 gallon tank housing the P. sp. ‘Gray Back’, are further filtered by two Aquaclear external filters. Aquaclear 110s on the 110 gallon tank and Aquaclear 70s on the 55 gallon tank. Also changing 40% of the water at least weekly but while not exact, closer to three times every two weeks.

My experience with the Lake Mweru species started out on a quick high note. My young group of six wild T. sparmannii was initially placed in a 20 gallon tall tank to grow out. They were only about an inch in length when received. Regardless of that diminutive size, a pair formed and I had my first spawn within a couple weeks. The fry of this species are the smallest I have come across in my years of keeping fish, so small in fact that I was nervous about them even being able to start out with feedings of microworms. The pair had claimed a terra cotta cichlid cave at the front (tank facing sideways on rack) of the tank. The spawn produced about 30 – 40 fry. I was able to remove about 20 fry and placed them in a large Marina external breeder box. Feeding them did turn out to be a bit of challenge based on their very small size but they did fairly well on a steady initial diet of the microworms. About half of those taken survived. The fry that I left in the tank with the parents slowly disappeared. After that initial spawn I moved them to a twenty gallon long, which I figured would give them a little more real estate to spread out over while they continued to grow out. I eventually moved them to a 40 gallon breeder which is where they currently remain. I have not had a subsequent spawn following the initial unexpected spawn described above. They have grown considerably and spawning activity/interest seems to be picking up. I have been offering them a diet of spirulina flakes (daily), NorthFin Veggie Bites (daily to every other day), blanched zucchini slices (weekly), and an occasional rare treat of frozen blood worms.

I have also had some success with spawning S. stappersi. This is the second species that I initially obtained as described above. A group of eight started out in a 40 gallon breeder tank decorated with one medium rock placed a few inches from each pane of glass in each corner of the tank and a few terra cotta cichlid caves in the center part of the tank. They initially shared the tank with groups of young Aulonocara kandeense ‘Blue Orchid’ and Stigmatochromis modestus. I started out with an even mix of four males and four females. One male took on the dominant role and pretty much kept the other males behind a corner sponge filter. This male dug a shallow pit in the cichlid sand between the rock and the corner of the tank in two of the four corners of the tank. He would alternate his time between the two pits, constantly displaying to the females. The male truly is stunning when actively in spawning mode. The large size and red coloration of the egg spots on the male’s anal fin is something to behold. In a short period of time I had spawns from all four females. Spawns typically produced 30 – 40 small eggs. While small they are not as small as those produced by T. sparmannii. Typically would strip the fry from the holding females 10 – 12 days post spawning and transfer them to Marina external breeder boxes. Thus far, I have managed to grow out fry however I have experienced a fairly large mortality rate with the sp

awns of this species. They do well initially but seem to struggle around the time of reaching a third to a half an inch in length. The group is now currently in a 30 gallon breeder with no other tank mates. I had moved them from the 40 gallon breeder tank to a 90 gallon tank along with groups of Paralabidochromis chromogynos and Stigmatochromis modestus. They did not fare to well in the 90 with this mix of species. The P. chromogynos simply dominated the S. stappersi and also claimed the same sections of the tank that the S. stappersi would have. They have settled into the 30 gallon breeder and I have had my first spawn in that tank in early November. I have been offering them a diet of spirulina flakes, as well as NorthFin Veggie pellets, NorthFin Cichlid pellets, NorthFin KrillPro pellets or freeze dried krill on a daily basis, supplementing with frozen blood worms twice weekly.

Regrettably cannot claim any spawning success yet with P. sp. ‘Gray Back’ or S. sp. ‘Large Tooth Group’. That being said, I am very hopeful to have first spawn of P. sp. ‘Gray Back’ in the very near future. I initially started out with 10 wild ‘Gray Back’. They were around 1” – 1.5” in length. They started out in a 30 gallon breeder. The group is now down to five and I believe I have 2 males and 3 females. This species does not ship very well and I lost three of the ten fairly quickly after receipt, having developed external fungal issues. Another was a male who lost a battle with the now dominant male and the other was a jumper who I found too late. They are currently in a 55 gallon tank with a group of Cyprichromis sp. ‘Brilliant Jumbo’ Tembwe ‘Speckleback Rainbow’. The dominant male has dug a shallow pit in the cichlid sand in the left third of the tank, toward the front glass. It is just adjacent to a 6” terra cotta flower pot. The male is actively courting what I believe are the three females and a couple of the females have appeared ripe in the belly and appear to have started to drop their spawning tube. Hoping for a mouth full soon! I have been offering them a diet of spirulina flakes, as well as NorthFin Veggie pellets, NorthFin Cichlid pellets, or NorthFin KrillPro pellets on a daily basis, supplementing with freeze dried krill or frozen blood worms once or twice a week.

I have no doubt that successfully spawning S. sp. ‘Large Tooth Group’ is going to prove to be a challenge. I currently have three of the initial six or seven that I had originally received. Three of four of the initial group of ten turned out to be S. stappersi. The initial six to seven varied greatly in size with a couple around 1” and the largest around 6-7”. With the three that I still have, one is a male and is now around 9”, a second is a presumed female at around 6”, and a third is unknown (but I am leaning toward a second female) at around 3”. The three or four that I lost were lost early on due to conspecific aggression and I failed to segregate the fish quickly enough. Currently the 3” fish is in a 30 gallon tank growing out with six Trematochromis benthicola. The other two are separated into halves of a now divided 110 gallon five foot tank. The larger male has his side all to himself. The female is currently sharing her side with a couple female Otopharynx tetrastigma, a pair of Auloncara masinje ‘Red Shoulder’, and 5 adult Synodontis multipunctatus. They were all coexisting in this tank undivided to a point when the male started to show some keen interest in the female. Regrettably she was not ready to show the reciprocal interest and I had to construct a DIY tank divider as quickly as possible. A couple current thoughts/plans I have is to one, get them into a 8 foot tank and two, get all three of them together thinking that the aggression would be reduced if the male had two females to occupy his time. To date their diet is pretty simple and consists of only freeze dried krill. I have not been able to get them to accept any other food to date.

In a perfect world, I would have unlimited funds and tank space, and would take on additional Lake Mweru species. I have found them to be both interesting and challenging. I hope to have young of all four of my current species available soon to spread amongst the NECA and beyond.