A new study looks at the impact the rapid moving waters of the Congo River have on cichlid species. Cichlid species living in fast moving waters tend to have elongated bodies and smaller swim bladders in order to cope with currents. However, a new genetic study has shown that these same fast currents also isolate and diversify the many species within the river.
The strong currents of the Congo River have played a major role in the diversification of species that are separated by relatively short distances. The study has shown that the fast moving waters have created pockets where groups have been isolated long enough to diversify genetically despite the lack of any physical barriers separating them. The article was published in Molecular Ecology. A short, free synopsis of the article can be found on ScienceDaily.com. To discuss Teleogramma brichardi and other species from the Congo River visit the West African Species forum.
Chromidotilapia guntheri is a unique cichlid with widespread distribution along the coastal basin of West Africa. There is also a critically endangered subspecies, C. guntheri loennbergi, found in and around the Barombi-ba-Kotto crater lake.
In the aquarium Chromidotilapia guntheri are best kept as a pair with other non-aggressive or predatory fish. Despite reaching 7+ inches in length, C. guntheri don’t do well when housed with aggressive fish. A unique characteristic of this species is that they are paternal mouthbrooders. After the eggs are deposited by the female and fertilized by the male, the male picks them up and broods them until they are ready to be released. During this time the female defends their territory. Once the fry are free-swimming, both parents will care for them and take them into their mouths when needed.
New research published in Nature Communications claims to explain how so many different species evolved in Lake Victoria in a short period of time. The study titled “Ancient hybridization fuels rapid cichlid fish adaptive radiations” determined that an explosion of species in the region was the result of hybridization between cichlids from different regions of Africa.
According to the study the hybridization took place during a wet period when Nile cichlids and Congo cichlids came together in the Lake Victoria region about 150,000 years ago. The resulting hybrid populations diversified to fit the different niches throughout the area. The entire article can be found on the Nature Communications website. For discussion visit the Lake Victoria Basin forum.
Herichthys minckleyi, found in the unique Cuatro Cienegas waters, has been observed displaying a unique spawning behavior. Since dominant males tend to horde all the females for themselves, smaller males have been observed sneaking into the spawning process in order to fertilize some of the eggs themselves. This behavior was observed and recorded by Ronald Oldfield. Details were published in Hydrobiologia but are behind a paywall. A description on the sneaky behavior by Herichthys minckleyi can be found on ScienceDaily.com. A video of the spawning behavior was posted on the Case Western Reserve University Youtube page.
A fish rarely found in the hobby, Thoracochromis demeusii comes from the lower Congo River in the Democratic Republic of the Congo. Males develop a hump on their head as they mature, but nothing as large as Cyphotilapia frontosa or other cichlid species with nuchal humps.
Thoracochromis demeusii are maternal mouthbrooders that live in the Congo River and in surrounding rivers and streams. They are considered threatened by mining in the region as well as dam construction. While only reaching about 5 inches in length, T. demeusii is also harvested as a food source in the region. To discuss this species and others from the region visit the West African forum.
LightSearch has posted several uncut video from Ndole Bay in Lake Tanganyika. The video below is 5 hours long, shot from a stationary position allowing us to see this fish behaving naturally.
The video is of shell dwellers going about their business. In the foreground some ‘Lamprologus’ multifasciatus tend to their shells. Beyond the ‘L.’ multifasciatus different fish can be seen including Altolamprologus compressiceps Sumbu, a shell dwelling “calvus” type. Ndole Bay is in the southern part of Lake Tanganyika and is the home to many species often seen in the hobby.
A new study on cichlid communication was conducted on Neolamprologus pulcher from Lake Tanganyika. The study was designed to see if chemical communication was used among N. pulcher. While visual and acoustic communication has been studied in the past, this study focused on chemical forms of communication. Turn out that forms of cichlid communication take place with the use of urine.
Since this was a urine in the water study, a dye was used to show fish urination. When two N. pulcher saw each other, they became aggressive and started to urinate. If the barrier between them didn’t allow them to come in contact with each other’s urine, they urinated much more than they would have if they were in the same tank. Apparently dominance can be transmitted in urine. For a synopsis of the study check out Springer.com. Unfortunately it is behind a paywall. To discuss Neolamprologus pulcher visit the Lake Tanganyika Species forum.
The CARES Preservation Program has just launched a new website at caresforfish.org. For those not familiar with the CARES program there is a short article by Lee Ann Steeves giving an overview on the program. Along with the new website, new articles have been published including one from Stuart M. Grant on the Rift Lakes of Africa.
“The purpose of the CARES Preservation Program is to create a base stock of conservation priority species through encouraging hobbyists worldwide to devote tank space to one or more species at risk and distribute offspring to fellow qualified hobbyists, while forming an information network where possible between aquarists, scientists, and conservationists.”
For more information and to take part in the program visit the CARES website.
A real beauty originally from Lake Victoria, Xystichromis phytophagus is now found in the protective papyrus stands of Lake Kanyaboli. X. phytophagus is possibly extinct in Lake Victoria due to the Nile Perch and hybridization due to cloudy water conditions from erosion and farming runoff.
In the aquarium Xystichromis phytophagus is like many other Lake Victoria region cichlids. They are hardy species that accept all types of food and a variety of water conditions. Males can be extremely aggressive toward other males and even females who are unwilling to spawn are picked on. They are best kept in groups on one male to multiple females. X. phytophagus gained popularity about 15 years ago when images like the one above started showing the species’ wonderful coloration. For more information check out the species article by Greg Steeves and visit the Lake Victoria Basin forum for discussions.
A short video by apanhaesta showing a holding Xenotilapia spilopterus.
Xenotilapia is a genus of fish from Lake Tanganyika characterized by an elongated shape and various colors along the body and fins. The appear and are quite delicate. Stress and rapid water condition changes can be deadly. They live in large groups along sand close to shore throughout the lake.
In the aquarium Xenotilapia spilopterus would do best in a species only tank or with mild mannered tankmates. Sand is a must, especially if you will to see their unique brooding behavior. A pair will spawn in an small sand pit. What happens afterwards is only found in a few other genus. X. spilopterus a biparental mouthbrooders. About halfway through the mouth-brooding process the female will spit out the eggs for the male to collect them. He will then continue to carry the developing fry until they are old enough to be released. This type of behavior is also found in Eretmodus cyanostictus.