The Njesi Highlands ( Portuguese : Serra Jeci ) are a range of mountains in northern Mozambique .
104-493: The highlands rise east of Lake Malawi in the western portion of Mozambique's Niassa Province . They are north of Lichinga , the provincial capital. The highest peaks are three inselbergs , the Njesi Plateau (1,843 m), Mount Chitagal (1,784 m), and Mount Sanga (1,782 m). The three peaks form part of a ridgeline that runs southwest to northeast. The Njesi Plateau is the southernmost peak, 30km from Mount Chitagal, and Mount Sanga
208-419: A behavioral change such that they become less receptive to outside interactions. This is often coupled with some physiological change in appearance. Cichlids can have maternal, paternal, or biparental care. Maternal care is most common among mouthbrooders, but cichlids' common ancestor is thought to exhibit paternal-only care. Other individuals outside of the parents may also play a role in raising young; in
312-496: A considerably older lake with a basin that started to form about 8.6 mya and deep-water condition first appeared 4.5 mya. The water levels have varied dramatically over time, ranging from almost 600 m (2,000 ft) below current level to 10–20 m (33–66 ft) above. During periods the lake dried out almost completely, leaving only one or two relatively small, highly alkaline and saline lakes in what currently are Malawi's deepest parts. A water chemistry resembling
416-454: A depth of 528 m (1,732 ft). The southern half of the lake is shallower; less than 400 m (1,300 ft) in the south-central part and less than 200 m (660 ft) in the far south. The lake has shorelines on western Mozambique , eastern Malawi , and southern Tanzania . The largest river flowing into it is the Ruhuhu River , and there is an outlet at its southern end,
520-417: A few hundred metres long. 1. Diplotaxodon , one of the very few cichlid genera that occurs offshore in relatively deep water. 2. Nimbochromis livingstonii is a piscivorous hap that is famous for playing dead to lure prey close. 3. As typical of utaka , Copadichromis azureus has bright blue males (shown) and duller females that are silvery with dark spots. 4. Aulonocara stuartgranti
624-575: A few hundred years ago. The Malawi haplochromines are mouthbrooders , but otherwise vary extensively in general behaviour and ecology. Within the Malawi haplochromines there are two main groups, the haps and the mbuna . The haps (they were formerly included in Haplochromis ) can be further subdivided into three subgroups: The relatively large, often more than 20 cm (8 in) long, and aggressive piscivores that roam various habitats in pursuit of prey,
728-401: A male and female leads to courtship. Courtship in male cichlids follows the establishment of some form of territory, sometimes coupled with building a bower to attract mates. After this, males may attempt to attract female cichlids to their territories by a variety of lekking display strategies or otherwise seek out females of their species. However, cichlids, at the time of spawning, undergo
832-648: A manner comparable to the egg-spots on the anal fin of haplochromines. The vast majority of the fish species in the lake are cichlids. Among the non-cichlid native fish are several species of cyprinids (in genera Barbus , Labeo and Opsaridium , and the Lake Malawi sardine Engraulicypris sardella ), airbreathing catfish ( Bathyclarias and Clarias , and the kampango Bagrus meridionalis ), mochokid catfish ( Chiloglanis and Malawi squeaker Synodontis njassae ), Mastacembelus spiny eel, mormyrids ( Marcusenius , Mormyrops and Petrocephalus ),
936-604: A mating partner is unavailable. Pit spawning, also referred to as substrate breeding, is a behavior in cichlid fish in which a fish builds a pit in the sand or ground, where a pair court and consequently spawn. Many different factors go into this behavior of pit spawning, including female choice of the male and pit size, as well as the male defense of the pits once they are dug in the sand. Cichlids are often divided into two main groups: mouthbrooders and substrate brooders. Different parenting investment levels and behaviors are associated with each type of reproduction. As pit spawning
1040-480: A minor part of their diets. Other cichlids are detritivores and eat organic material, called Aufwuchs (offal); among these species are the tilapiines of the genera Oreochromis , Sarotherodon , and Tilapia . Other cichlids are predatory and eat little or no plant matter. These include generalists that catch a variety of small animals, including other fishes and insect larvae (e.g. Pterophyllum ), as well as variety of specialists. Trematocranus
1144-507: A mixed school of young have also been observed in multiple cichlid species, including Amphilophus citrinellus , Etroplus suratensis , and Tilapia rendalli . Comparably, the fry of Neolamprologus brichardi , a species that commonly lives in large groups, are protected not only by the adults, but also by older juveniles from previous spawns. Several cichlids, including discus ( Symphysodon spp.), some Amphilophus species, Etroplus , and Uaru species, feed their young with
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#17330851339071248-442: A remarkably rapid change in coloration, during which a successfully dominant territorial male assumes a more vivid and brighter coloration, while a subordinate or "nonterritorial" male assumes a dull-pale coloration. In addition to color displays, cichlids employ their lateral lines to sense movements of water around their opponents to evaluate the competing male for physical traits/fitness. Male cichlids are very territorial due to
1352-425: A significant population of African fish eagles that feed off fish from the lake. Lake Malawi has for millennia provided a major food source to the residents of its shores since its waters are rich in fish. Among the most popular are the four species of chambo, consisting of any one of four species in the subgenus Nyasalapia ( Oreochromis karongae , O. lidole , O. saka and O. squamipinnis ), as well as
1456-505: A skin secretion from mucous glands. The species Neolamprologus pulcher uses a cooperative breeding system, in which one breeding pair has many helpers that are subordinate to the dominant breeders. Parental care falls into one of four categories: substrate or open brooders, secretive cave brooders (also known as guarding speleophils ), and at least two types of mouthbrooders , ovophile mouthbrooders and larvophile mouthbrooders. Open- or substrate-brooding cichlids lay their eggs in
1560-491: A time, attaching them to the spawning surface, which may be a pit constructed on the substrate or another surface. The number of eggs laid was correlated to the space available on the substrate. Once the eggs were attached, the male swam over the eggs and fertilized them. The parents would then dig pits in the sand, 10–20 cm wide and 5–10 cm deep, where larvae were transferred after hatching. Larvae began swimming 8 days after fertilization and parenting behaviors and some of
1664-517: A very wide variety of food items. This is assumed to be one reason why they are so diverse. The features that distinguish them from the other families in the Labroidei include: Kullander (1998) recognizes eight subfamilies of cichlids: the Astronotinae , Cichlasomatinae , Cichlinae , Etroplinae , Geophaginae , Heterochromidinae , Pseudocrenilabrinae , and Retroculinae . A ninth subfamily,
1768-499: A wider variety of foods based on availability. Carnivorous cichlids can be further divided into piscivorous and molluscivorous, since the morphology and hunting behavior differ greatly between the two categories. Piscivorous cichlids eat other fish, fry, larvae, and eggs. Some species eat the offspring of mouthbrooders by head-ramming, wherein the hunter shoves its head into the mouth of a female to expel her young and eat them. Molluscivorous cichlids have several hunting strategies amongst
1872-702: Is 25 km north of Mount Chitagal. Lake Malawi known in Mozambique as Lake Niassa, lies in the East African Rift , and the ridge and the highlands form part of the rift valley's eastern wall. The western slope of the highlands is drained by the Messinge River, and the Luchulingo River drains the eastern slope. Both rivers are northward-flowing tributaries of the Rovuma River . The Messinge River valley separates
1976-497: Is a reproductive behavior, many different physiological changes occur in the cichlid while this process is occurring that interfere with social interaction. Different kinds of species that pit spawn, and many different morphological changes occur because of this behavioral experience. Pit spawning is an evolved behavior across the cichlid group. Phylogenetic evidence from cichlids in Lake Tanganyika could be helpful in uncovering
2080-508: Is a specialized snail -eater, while Pungu maclareni feeds on sponges . A number of cichlids feed on other fish, either entirely or in part. Crenicichla species are stealth predators that lunge from concealment at passing small fish, while Rhamphochromis species are open-water pursuit predators that chase down their prey. Paedophagous cichlids such as the Caprichromis species eat other species' eggs or young, in some cases ramming
2184-421: Is alkaline ( pH 7.7–8.6) and warm with a typical surface temperature between 24 and 29 °C (75–84 °F), while deep sections typically are about 22 °C (72 °F). The thermocline is located at a depth of 40–100 m (130–330 ft). The oxygen limit is at a depth of approximately 250 m (820 ft), effectively restricting fish and other aerobic organisms to the upper part. The water
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#17330851339072288-464: Is also the case for Etroplus maculatus and E. suratensis from India and Sri Lanka. Within the cichlid family, carnivores, herbivores, omnivores, planktivores, and detritivores are known, meaning the Cichlidae encompass essentially the full range of food consumption possible in the animal kingdom. Various species have morphological adaptations for specific food sources, but most cichlids consume
2392-513: Is an African Great Lake and the southernmost lake in the East African Rift system, located between Malawi , Mozambique and Tanzania. It is the fourth largest freshwater lake in the world by volume, the ninth largest lake in the world by area and the third largest and second deepest lake in Africa. Lake Malawi is home to more species of fish than any other lake in the world, including at least 700 species of cichlids . The Mozambique portion of
2496-717: Is based on body movements, such as shaking and pelvic fin flicking. In addition, open- and cave-brooding parents assist in finding food resources for their fry. Multiple neotropical cichlid species perform leaf-turning and fin-digging behaviors. Ovophile mouthbrooders incubate their eggs in their mouths as soon as they are laid, and frequently mouthbrood free-swimming fry for several weeks. Examples include many East African Rift lakes ( Lake Malawi , Lake Tanganyika , and Lake Victoria ) endemics, e.g.: Maylandia , Pseudotropheus , Tropheus , and Astatotilapia burtoni , along with some South American cichlids such as Geophagus steindachneri . Larvophile mouthbrooders lay eggs in
2600-479: Is believed to have been a spit-spawning species. Both Madagascar and Indian cichlids retain this feature. However, of the African cichlids, all extant substrate brooding species originate solely from Lake Tanganyika. The ancestor of the Lake Malawi and Lake Victoria cichlids were mouthbrooders. Similarly, only around 30% of South American cichlids are thought to retain the ancestral substrate-brooding trait. Mouthbrooding
2704-415: Is between 560 kilometres (350 mi) and 580 kilometres (360 mi) long, and about 75 kilometres (47 mi) wide at its widest point. The lake has a total surface area of about 29,600 square kilometres (11,400 sq mi). The lake is 706 m (2,316 ft) at its deepest point , located in a major depression in the north-central part. Another smaller depression in the far north reaches
2808-534: Is equally at home in freshwater marshes and mangrove swamps, and lives and breeds in saltwater environments such as the mangrove belts around barrier islands . Several species of Tilapia , Sarotherodon , and Oreochromis are euryhaline and can disperse along brackish coastlines between rivers. Only a few cichlids, however, inhabit primarily brackish or salt water, most notably Etroplus maculatus , Etroplus suratensis , and Sarotherodon melanotheron . The perhaps most extreme habitats for cichlids are
2912-841: Is found over 900 km north in the Usambara Mountains of Tanzania. Other bird species found in the highlands include the montane nightjar ( Caprimulgus poliocephalus ), eastern green tinkerbird ( Pogoniulus simplex ), dark batis ( Batis crypta ), yellow-streaked greenbul ( Phyllastrephus flavostriatus ), Eurasian blackcap ( Sylvia atricapilla ), dapple-throat ( Arcanator orostruthus ), green twinspot ( Mandingoa nitidula ), Southern citril ( Crithagra hyposticta ), and Vincent's bunting ( Emberiza vincenti ). Lake Malawi Lake Malawi , also known as Lake Nyasa in Tanzania and Lago Niassa in Mozambique , ( Swahili : Ziwa Nyasa )
3016-469: Is located at the southern end of the lake. Malawi is one of the major Rift Valley lakes and an ancient lake . The lake lies in a valley formed by the opening of the East African Rift , where the African tectonic plate is being split into two pieces. This is called a divergent plate tectonics boundary. Malawi has typically been estimated to be 1–2 million years old (mya), but more recent evidence points to
3120-583: Is not found in the lake. Pelagic zooplanktonic species include two cladocerans ( Diaphanosoma excisum and Bosmina longirostris ), three copepods ( Tropodiaptomus cunningtoni , Thermocyclops neglectus and Mesocyclops aequatorialis ), and several ostracods (including both described and undescribed species ). Lake Malawi is famous for the huge swarms of tiny, harmless lake flies, Chaoborus edulis . These swarms, typically appearing far out over water, can be mistaken for plumes of smoke and were also noticed by David Livingstone when he visited
3224-570: Is part of a group of relatively peaceful species popularly known as peacock cichlids . 5. Fossorochromis rostratus is an "aberrant" hap that often sifts mouthfuls of sand to extract small food organisms. 6. Like many mbuna , Pseudotropheus saulosi is a small cichlid where both male (blue and black) and female (yellow) are colorful. Lake Malawi is noted for being the site of evolutionary radiations among several groups of animals, most notably cichlid fish. There are at least 700 cichlid species in Lake Malawi, with some estimating that
Njesi Highlands - Misplaced Pages Continue
3328-573: Is probably the convict blenny , and both families are classified in the 5th edition of Fishes of the World as the two families in the Cichliformes, part of the subseries Ovalentaria . This family is large, diverse, and widely dispersed. At least 1,650 species have been scientifically described , making it one of the largest vertebrate families. New species are discovered annually, and many species remain undescribed . The actual number of species
3432-486: Is therefore unknown, with estimates varying between 2,000 and 3,000. Many cichlids, particularly tilapia , are important food fishes, while others, such as the Cichla species, are valued game fish. The family also includes many popular freshwater aquarium fish kept by hobbyists, including the angelfish , oscars , and discus . Cichlids have the largest number of endangered species among vertebrate families, most in
3536-596: Is thought to have evolved individually up to 14 times, and a return to substrate brooding as many as three separate times between both African and Neotropical species. Cichlids have a great variety of behaviors associated with substrate brooding, including courtship and parental care alongside the brooding and nest-building behaviors needed for pit spawning. Cichlids' behavior typically revolves around establishing and defending territories when not courting, brooding, or raising young. Encounters between males and males or females and females are agonistic, while an encounter between
3640-471: Is under dispute. Tanzania claims that the international border runs through the middle of the lake. On the other hand, Malawi claims the whole of the surface of this lake that is not in Mozambique, including the waters that are next to the shoreline of Tanzania. Both sides cite the Heligoland Treaty of 1890 between Great Britain and Germany concerning the border. The wrangle in this dispute occurred when
3744-442: Is very clear for a lake and the visibility can be up to 20 m (66 ft), but slightly less than half this figure is more common and it is below 3 m (10 ft) in muddy bays. However, during the rainy season months of January to March, the waters are more muddy due to muddy river inflows. The Portuguese trader Candido José da Costa Cardoso was the first European to visit the lake in 1846. David Livingstone reached
3848-451: The African tetra Brycinus imberi , the poeciliid Aplocheilichthys johnstoni , the spotted killifish ( Nothobranchius orthonotus ), and the mottled eel ( Anguilla nebulosa ). At a genus level, most of these are widespread in Africa, but Bathyclarias is entirely restricted to the lake. Lake Malawi is home to 28 species of freshwater snails (including 16 endemics) and 9 bivalves (2 endemics, Aspatharia subreniformis and
3952-676: The Hermann von Wissmann in a bay near Sphinxhaven , in German East African territorial waters. Gwendolen disabled the German boat with a single cannon shot from a range of about 1,800 metres (2,000 yd). This brief conflict was hailed by The Times in England as the British Empire's first naval victory of World War I. The partition of the lake's surface area between Malawi and Tanzania
4056-466: The Ptychochrominae , was later recognized by Sparks and Smith. Cichlid taxonomy is still debated, and classification of genera cannot yet be definitively given. A comprehensive system of assigning species to monophyletic genera is still lacking, and there is not complete agreement on what genera should be recognized in this family. As an example of the classification problems, Kullander placed
4160-946: The Rio Grande in South Texas . Madagascar has its own distinctive species ( Katria , Oxylapia , Paratilapia , Paretroplus , Ptychochromis , and Ptychochromoides ), only distantly related to those on the African mainland. Native cichlids are largely absent in Asia, except for 9 species in Israel , Lebanon , and Syria ( Astatotilapia flaviijosephi , Oreochromis aureus , O. niloticus , Sarotherodon galilaeus , Coptodon zillii , and Tristramella spp.), two in Iran ( Iranocichla ), and three in India and Sri Lanka ( Etroplus and Pseudetroplus ). If disregarding Trinidad and Tobago (where
4264-563: The Shire River , a tributary that flows into the Zambezi River in Mozambique. Evaporation accounts for more than 80% of the water loss from the lake, considerably more than the outflowing Shire River. The outflows from Lake Malawi into the Shire River are vital for the economy as the water resources support hydropower, irrigation and downstream biodiversity. Concerns have been raised over
Njesi Highlands - Misplaced Pages Continue
4368-591: The haplochromine group. Cichlids are particularly well known for having evolved rapidly into many closely related but morphologically diverse species within large lakes, particularly Lakes Tanganyika , Victoria , Malawi , and Edward . Their diversity in the African Great Lakes is important for the study of speciation in evolution. Many cichlids introduced into waters outside of their natural range have become nuisances. All cichlids practice some form of parental care for their eggs and fry, usually in
4472-405: The new world , can be classified under the subfamily Cichlinae, while Etroplinae can classify all cichlid species native to the old world . Cichlids are one of the largest vertebrate families in the world. They are most diverse in Africa and South America. Africa alone is host to at least an estimated 1,600 species. Central America and Mexico have about 120 species, as far north as
4576-489: The unionid Nyassunio nyassaensis ). The endemic freshwater snails are all members of the genera Bellamya , Bulinus , Gabbiella , Lanistes and Melanoides . Lake Malawi is home to a total of four snail species in the genus Bulinus , which is a known intermediate host of bilharzia . A survey in Monkey Bay in 1964 found two endemic species of snails of the genus ( B. nyassanus and B. succinoides ) in
4680-527: The 20th century the mountains had been little surveyed by biologists, due in part to the long Mozambican Civil War from the mid-1970s to the 1990s. Large mammals include the African buffalo ( Syncerus caffer ), klipspringer ( Oreotragus oreotragus ), sable antelope ( Hippotragus niger ), bushpig ( Potamochoerus larvatus ), leopard ( Panthera pardus ), side-striped jackal ( Canis adustus ), spotted hyena ( Crocuta crocuta ), and yellow baboon ( Papio cynocephalus ). 21st-century biological surveys of
4784-523: The African cichlids, can be further split either into Eastern and Western varieties, or into groups depending on which lake the species is from: Lake Malawi , Lake Victoria , or Lake Tanganyika . Of these subgroups, the Madagascar and Indian cichlids are the most basal and least diverse. Of the African cichlids, the West African or Lake Tanganyika cichlids are the most basal. Cichlids' common ancestor
4888-529: The African genus Heterochromis phylogenetically within Neotropical cichlids, although later papers concluded otherwise. Other problems center upon the identity of the putative common ancestor for the Lake Victoria superflock (many closely related species sharing a single habitat), and the ancestral lineages of Lake Tanganyikan cichlids. Phylogeny derived from morphological characters shows differences at
4992-773: The British and are now part of Malawi. MV Chauncy Maples began service on the lake in 1901 as the SS Chauncy Maples : a floating clinic and church for the Universities' Mission to Central Africa . She later served as a ferry and is currently being renovated into a mobile clinic at Monkey Bay . The renovation was expected to be complete during the first half of 2014, but was halted in 2017. MV Mpasa entered service in 1935. The ferry MV Ilala entered service in 1951. In recent years she has often been out of service, but when operational she runs between Monkey Bay at
5096-484: The British colonial government, just after they had captured Tanganyika from Germany, placed all of the waters of the lake under a single jurisdiction, that of the territory of Nyasaland , without a separate administration for the Tanganyikan portion of the surface. Later in colonial times, two jurisdictions were established. The dispute came to a head in 1967 when Tanzania officially protested to Malawi; however nothing
5200-649: The Lake of Storms. On 16 August 1914, Lake Malawi was the scene of a brief naval battle during World War I . The British gunboat SS Gwendolen , commanded by a Captain Rhoades, received orders from the British Empire's high command to "sink, burn, or destroy" the German Empire's only gunboat on the lake, the Hermann von Wissmann , commanded by Captain Berndt. Rhoades's crew found
5304-589: The Malawi system, which also includes nearby smaller Lake Malombe and the upper Shire River. Many of these have become popular among aquarium owners due to their bright colors. Recreating a Lake Malawi biotope to host cichlids became quite popular in the aquarium hobby. Most Malawi cichlids are found in relatively shallow coastal waters, but Diplotaxodon has been recorded down to depths of 200–220 m (660–720 ft) and several (especially Diplotaxodon , Rhamphochromis and Copadichromis quadrimaculatus ) are known from pelagic waters. The cichlids of
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#17330851339075408-451: The Njesi Plateau from Serra Macuta, a similar plateau lying to the west. The highlands are mostly covered in miombo woodland , and are in the eastern Miombo woodlands ecoregion. The three peaks include patches of Afromontane forest, higher-elevation evergreen forests which are home to species distinct from those of the surrounding lowlands. Other higher-elevation plant communities include Afromontane grassland and protea shrubland. In
5512-554: The North American sunfishes in morphology, behavior, and ecology. Cichlids share a single key trait - the fusion of the lower pharyngeal bones into a single tooth-bearing structure. A complex set of muscles allows the upper and lower pharyngeal bones to be used as a second set of jaws for processing food, allowing a division of labor between the "true jaws" ( mandibles ) and the " pharyngeal jaws ". Cichlids are efficient and often highly specialized feeders that capture and process
5616-416: The actual figure is as high as 1,000 species. The actual number is labelled with some uncertainty because of the many undescribed species and the extreme variation among some species, making the task of delimiting them very complex. Except for four species ( Astatotilapia calliptera , Coptodon rendalli , Oreochromis shiranus and Serranochromis robustus ), all cichlids in the lake are endemic to
5720-520: The adults die. The larvae are an important food source for fish, and the adult flies are important both to birds and local people, who collect them to make kungu cakes/burgers, a local delicacy with a very high protein content. In January 2015, a sediment control tank collapsed at the Paladin Energy -owned uranium mine in Northern Malawi after a high intensity rain storm hit the area. It
5824-487: The anal fin (specifically the genital papilla) of the male, which is when he discharges sperm into her mouth and fertilizes the eggs. The genuine color of egg spots is a yellow, red, or orange inner circle with a colorless ring surrounding the shape. Through phylogenetic analysis, using the mitochondrial ND2 gene, the true egg spots are thought to have evolved in the common ancestor of the Astatoreochromis lineage and
5928-432: The bilharzia parasite. Unlike Lake Tanganyika with its many endemic freshwater crabs and shrimp, there are few such species in Lake Malawi. The Malawi blue crab, Potamonautes lirrangensis ( syn. P. orbitospinus ), is the only crab in the lake and it is not endemic. The atyid shrimp Caridina malawensis is endemic to the lake, but it is poorly known and has historically been confused with C. nilotica , which
6032-456: The biparental daffodil cichlid ( Neolamprologus pulcher ), closely related satellite males, those males that surround other males' territories and attempt to mate with female cichlids in the area, help rear the primary males' offspring and their own. A common form of brood care involves food provisioning. For example, females of lyretail cichlids ( Neolamprologus modabu ) dig at sandy substrate more to push nutritional detritus and zooplankton into
6136-416: The cichlid tribe Haplochromini, exhibit a unique pattern of oval-shaped color dots on their anal fins. These phenomena, known as egg spots, aid in the mouthbrooding mechanisms of cichlids. The egg spots consist of carotenoid-based pigment cells, which indicate a high cost to the organism, when considering that fish are not able to synthesize their own carotenoids. The mimicry of egg spots is used by males for
6240-480: The closely related O. shiranus . Other species that support important fisheries include the Lake Malawi sardine ( Engraulicypris sardella ) and the large kampango catfish ( Bagrus meridionalis ). Most fishing provides food for the increasing human population near the lake, but some are exported from Malawi. The wild population of fish is increasingly threatened by overfishing and water pollution . A drop in
6344-458: The current conditions only appeared about 60,000 years ago. Major low-water periods are estimated to have occurred about 1.6 to 1.0–0.57 million years ago (where it might have dried out completely), 420,000 to 250,000–110,000 years ago, about 25,000 years ago and 18,000–10,700 years ago. During the peak of the low-water period between 1390 and 1860 AD , it may have been 120–150 m (390–490 ft) below current water levels. The lake's water
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#17330851339076448-892: The details, the general basis of the behavior is the same. Mouthbrooding also affects how they choose their mates and breeding grounds. In a 1995 study, Nelson found that in pit-spawning females choose males for mating based on the size of the pit that they dig, as well as some of the physical characteristics seen in the males. Pit spawning also differs from mouth brooding in the size and postnatal care exhibited. Eggs that have been hatched from pit-spawning cichlids are usually smaller than those of mouthbrooders. Pit-spawners' eggs are usually around 2 mm, while mouthbrooders are typically around 7 mm. While different behaviors take place postnatally between mouthbrooders and pit spawners, some similarities exist. Females in both mouthbrooders and pit-spawning cichlids take care of their young after they are hatched. In some cases, both parents exhibit care, but
6552-527: The entire clade and within different communities across separate habitats. Within their phylogeny, many parallel instances are seen of lineages evolving to the same trait and multiple cases of reversion to an ancestral trait. The family Cichlidae arose between 80 and 100 million years ago within the order Perciformes (perch-like fishes). Cichlidae can be split into a few groups based on their geographic location: Madagascar, Indian, African, and Neotropical (or South American). The most famous and diverse group,
6656-466: The evolution of their reproductive behaviors. Several important behaviors are associated with pit spawning, including parental care, food provisioning, and brood guarding. One of the differences studied in African cichlids is reproductive behavior. Some species pit spawn and some are known as mouth brooders. Mouthbrooding is a reproductive technique where the fish scoop up eggs and fry for protection. While this behavior differs from species to species in
6760-760: The female always cares for the eggs and newly hatched fry. Many species of cichlids use pit spawning, but one of the less commonly studied species that exhibits this behavior is the Neotropical Cichlasoma dimerus . This fish is a substrate breeder that displays biparental care after the fry have hatched from their eggs. One study examined reproductive and social behaviors of this species to see how they accomplished their pit spawning, including different physiological factors such as hormone levels, color changes, and plasma cortisol levels. The entire spawning process could take about 90 minutes and 400~800 eggs could be laid. The female deposits about 10 eggs at
6864-439: The fertilization process. Mouthbrooding females lay eggs and immediately snatch them up with their mouths. Over millions of years, male cichlids have evolved egg spots to initiate the fertilization process more efficiently. When the females are snatching up the eggs into their mouth, the males gyrate their anal fins, which illuminates the egg spots on his tail. Afterwards, the female, believing these are her eggs, places her mouth to
6968-952: The few native cichlids are members of genera that are widespread in the South American mainland), the three species from the genus Nandopsis are the only cichlids from the Antilles in the Caribbean , specifically Cuba and Hispaniola . Europe, Australia, Antarctica, and North America north of the Rio Grande drainage have no native cichlids, although in Florida , Hawaii , Japan, northern Australia, and elsewhere, feral populations of cichlids have become established as exotics . Although most cichlids are found at relatively shallow depths, several exceptions do exist. The deepest known occurrences are Trematocara at more than 300 m (1,000 ft) below
7072-453: The first person to swim the full length of Lake Malawi (54 days), as well as setting the world record for longest solo swim in a lake Cichlid Alternate taxonomy: For genera , see below . Cichlids / ˈ s ɪ k l ɪ d z / are fish from the family Cichlidae in the order Cichliformes . Traditionally Cichlids were classed in a suborder, the Labroidei , along with
7176-787: The form of guarding the eggs and fry or mouthbrooding . Cichlids span a wide range of body sizes, from species as small as 2.5 cm (1 in) in length (e.g., female Neolamprologus multifasciatus ) to much larger species approaching 1 m (3 ft) in length ( Boulengerochromis and Cichla ). As a group, cichlids exhibit a similar diversity of body shapes, ranging from strongly laterally compressed species (such as Altolamprologus , Pterophyllum , and Symphysodon ) to species that are cylindrical and highly elongated (such as Julidochromis , Teleogramma , Teleocichla , Crenicichla , and Gobiocichla ). Generally, however, cichlids tend to be of medium size, ovate in shape, and slightly laterally compressed, and generally similar to
7280-401: The full range of parenting behaviours. Secretive cave-spawning cichlids lay their eggs in caves, crevices, holes, or discarded mollusc shells , frequently attaching the eggs to the roof of the chamber. Examples include Pelvicachromis spp., Archocentrus spp., and Apistogramma spp. Free-swimming fry and parents communicate in captivity and in the wild. Frequently, this communication
7384-482: The future climate change impacts of Lake Malawi due to the recent decline in lake levels and the overall drying trend. The climate in the lake region is already experiencing changes, with the temperatures predicted to increase throughout the country. The lake is about 350 kilometres (220 mi) southeast of Lake Tanganyika , another of the great lakes of the East African Rift. The Lake Malawi National Park
7488-453: The genus level with phylogeny based on genetic loci . A consensus remains that the Cichlidae as a family are monophyletic. In cichlid taxonomy, dentition was formerly used as a classifying characteristic, but this was complicated because in many cichlids, tooth shapes change with age, due to wear, and cannot be relied upon. Genome sequencing and other technologies transformed cichlid taxonomy. Alternatively, all cichlid species native to
7592-594: The heads of mouthbrooding species to force them to disgorge their young. Among the more unusual feeding strategies are those of Corematodus , Docimodus evelynae , Plecodus , Perissodus , and Genyochromis spp., which feed on scales and fins of other fishes, a behavior known as lepidophagy , along with the death-mimicking behaviour of Nimbochromis and Parachromis species, which lay motionless, luring small fish to their side prior to ambush. This variety of feeding styles has helped cichlids to inhabit similarly varied habitats. Its pharyngeal teeth (in
7696-499: The lake are divided into two groups and the vast majority of the species are haplochromines . The sister species to the Malawi haplochromines is Astatotilapia sp. Ruaha (a currently undescribed species from Great Ruaha River ), and these two separated between 2.13 and 6.76 million years ago (mya). The earliest divergence within the Malawi haplochromines occurred between 1.20 and 4.06 mya, but most radiations in this group are far younger; in extreme cases species may have diverged only
7800-430: The lake in 1859, and named it Lake Nyasa. He also referred to it by a pair of nicknames: Lake of Stars and Lake of Storms. The Lake of Stars nickname came after Livingstone observed lights from the lanterns of the fishermen in Malawi on their boats, that resemble, from a distance, stars in the sky. Later, after experiencing the unpredictable and extremely violent gales that sweep through the area, he also referred to it as
7904-543: The lake was officially declared a reserve by the Government of Mozambique on June 10, 2011, while in Malawi a portion of the lake is included in Lake Malawi National Park . Lake Malawi is a meromictic lake , meaning that its water layers do not mix. The permanent stratification of Lake Malawi's water and the oxic- anoxic boundary are maintained by moderately small chemical and thermal gradients . Lake Malawi
8008-569: The lake's water level represents another threat, and is believed to be driven by water extraction by the increasing human population, climate change and deforestation . The chambo and kampango have been particularly overfished (the kampango declined by about 90% from 2006 to 2016, O. karongae and O. squamipinnis by about 94%, and O. lidole might already be extinct ) and they are now seriously threatened . The IUCN recognises 117 species of Malawi cichlids as threatened; some of these have tiny ranges and may be restricted to rocky coastlines only
8112-491: The lake, and two non-endemic species ( B. globosus and B. forskalli ) in lagoons separated from it. The latter species are known intermediate hosts of bilharzia, and larvae of the parasite were detected in water containing these, but in experiments C. Wright of the British Museum of Natural History was unable to infect the two species endemic to the lake with the parasites. The field workers, who spent many hours on and in
8216-401: The lake, did not find either B. globosus or B. forskalli in the lake itself. More recently, the disease has become a problem in the lake itself as the endemic B. nyassanus has become an intermediate host. This change, first noticed in the mid-1980s, is possibly related to a decline in snail-eating cichlids (for example, Trematocranus placodon ) due to overfishing and/or a new strain of
8320-411: The lake. The aquatic larvae feed on zooplankton, spending the day at the bottom and the night in the upper water levels. When they pupate they float to the surface and transform into adult flies. The adults are very short-lived and the swarms, which can be several hundred metres tall and often have a spiraling shape, are part of their mating behaviour. They lay their eggs at the water's surface and
8424-516: The mbuna, a name used both locally and popularly, which means "rockfish" in Tonga . They are found at rocky outcrops, territorially aggressive (although commonly found in high densities) and often specialised aufwuchs feeders. The mbuna species tend to be relatively small, mostly less than 13 cm (5 in) long, and often both sexes are brightly colored with males having egg-shaped yellow spots on their anal fin (a feature particularly prevalent in
8528-460: The mbuna, but not exclusive to this group). The second group, the tilapia , comprises only six species in two genera in Lake Malawi: The redbreast tilapia ( Coptodon rendalli ), a widespread African species, is the only substrate-spawning cichlid in the lake. This large cichlid mainly feeds on macrophytes . The remaining are five mouthbrooding species of Oreochromis ; four chambo in
8632-602: The modern Haplochrominis species. This ancestor was most likely riverine in origin, based on the most parsimonious representation of habitat type in the cichlid family. The presence of egg spots in a turbid riverine environment would seem particularly beneficial and necessary for intraspecies communication. Two pigmentation genes are found to be associated with egg-spot patterning and color arrangement. These are fhl2-a and fhl2-b , which are paralogs. These genes aid in pattern formation and cell-fate determination in early embryonic development. The highest expression of these genes
8736-461: The mountain have documented some limited-range and endangered animals living in the highlands. These include the Mozambique forest warbler ( Artisornis sousae ) which is endemic to the highlands and lives in the Afromontane and riparian forests. It was identified as a separate species in 2016, and had previously been classed as a subspecies of the long-billed tailorbird ( Artisornis moreaui ), which
8840-436: The open, on rocks, leaves, or logs. Examples of open-brooding cichlids include Pterophyllum and Symphysodon species and Anomalochromis thomasi . Male and female parents usually engage in differing brooding roles. Most commonly, the male patrols the pair's territory and repels intruders, while the female fans water over the eggs, removing the infertile ones, and leading the fry while foraging. Both sexes are able to perform
8944-509: The open-water (although often not far from sand or rocks) utaka that feed in schools on zooplankton and typically are of medium size, and finally a subgroup of "aberrant" species that essentially are defined by them not fitting clearly into the other subgroups. Adult male haps generally display bright colors, while juveniles of both sexes and adult females typically show a silvery or grey coloration with sometimes irregular black bars or other markings. The second main haplochromine group are
9048-814: The physical aggression of males becomes a contest for resources (mates, territory, food). Female cichlids prefer to mate with a successfully alpha male with vivid coloration, whose territory has food readily available. Cichlids mate either monogamously or polygamously . The mating system of a given cichlid species is not consistently associated with its brooding system. For example, although most monogamous cichlids are not mouthbrooders, Chromidotilapia , Gymnogeophagus , Spathodus , and Tanganicodus all include – or consist entirely of – monogamous mouthbrooders. In contrast, numerous open- or cave-spawning cichlids are polygamous; examples include many Apistogramma , Lamprologus , Nannacara , and Pelvicachromis species. Most adult male cichlids, specifically in
9152-409: The physiological factors measured changed. In the same study, color changes were present before and after the pit spawning occurred. For example, after the larvae were transferred and the pits were beginning to be protected, their fins turned a dark grey color. In another study, of the rainbow cichlid, Herotilapia multispinosa , color changes occurred throughout the spawning process. Before spawning,
9256-640: The precise sister relationships predicted by vicariance : Africa-South America and India-Madagascar. The dispersal hypothesis, in contrast, requires cichlids to have negotiated thousands of kilometers of open ocean between India and Madagascar without colonizing any other island, or for that matter, crossing the Mozambique Channel to Africa. Although the vast majority of Malagasy cichlids are entirely restricted to fresh water, Ptychochromis grandidieri and Paretroplus polyactis are commonly found in coastal brackish water and are apparently salt tolerant, as
9360-421: The pressure of reproduction, and establish their territory and social status by physically driving out challenging males (novel intruders) through lateral displays (parallel orientation, uncovering gills), biting, or mouth fights (head-on collisions of open mouths, measuring jaw sizes, and biting each other's jaws). The cichlid social dichotomy is composed of a single dominant with multiple subordinates, where
9464-404: The rainbow cichlid was an olive color with grey bands. Once spawning behaviors started, the body and fins of the fish became a more golden color. When the eggs were finished being laid, the pelvic fin all the way back to the caudal fin turned to a darker color and blackened in both the males and the females. Females prefer a bigger pit size when choosing where to lay eggs. Differences are seen in
9568-408: The sizes of pits that created, as well as a change in the morphology of the pits. Evolutionary differences between species of fish may cause them to either create pits or castles when spawning. The differences were changes in the way that each species fed, their macrohabitats, and the abilities of their sensory systems. Cichlids are renowned for their recent, rapid evolutionary radiation, both across
9672-480: The southern end of the lake to Karonga on the northern end, and occasionally to the Iringa Region of Tanzania. The ferry MV Mtendere entered service in 1980. By 1982 she was carrying 100,000 passengers each year., but as of 2014 she was out of service. She normally serves the southern part of the lake but if Ilala was out of service she operated the route to Karonga. The Tanzanian ferry MV Songea
9776-577: The subgenus Nyasalapia ( O. karongae , O. lidole , O. saka and O. squamipinnis ) that are endemic to the Lake Malawi system, as well as the closely related O. shiranus , which also is found in Lake Chilwa . The Malawi Oreochromis mainly feed on phytoplankton , reach lengths up to 26–42 cm (10–17 in) depending on the exact species, and are mostly black or silvery-gray with relatively indistinct dark bars. Male chambo have unique genital tassels when breeding, which aid in egg fertilisation in
9880-691: The surface in Lake Tanganyika . Others found in relatively deep waters include species such as Alticorpus macrocleithrum and Pallidochromis tokolosh down to 150 m (500 ft) below the surface in Lake Malawi, and the whitish (non pigmented ) and blind Lamprologus lethops , which is believed to live as deep as 160 m (520 ft) below the surface in the Congo River . Cichlids are less commonly found in brackish and saltwater habitats, though many species tolerate brackish water for extended periods; Mayaheros urophthalmus , for example,
9984-775: The surrounding water. Adult of N. modabu perform this strategy to collect food for themselves, but dig more when offspring are present, likely to feed their fry. This substrate-disruption strategy is rather common and can also be seen in convict cichlids ( Cichlasoma nigrofasciatum ). Other cichlids have an ectothermal mucus that they grow and feed to their young, while still others chew and distribute caught food to offspring. These strategies, however, are less common in pit-spawning cichlids. Cichlids have highly organized breeding activities. All species show some form of parental care for both eggs and larvae , often nurturing free-swimming young until they are weeks or months old. Communal parental care, where multiple monogamous pairs care for
10088-406: The throat) afford cichlids so many "niche" feeding strategies, because the jaws pick and hold food, while the pharyngeal teeth crush the prey. Aggressive behavior in cichlids is ritualized and consists of multiple displays used to seek confrontation while being involved in evaluation of competitors, coinciding with temporal proximity to mating. Displays of ritualized aggression in cichlids include
10192-478: The varieties within the group. Lake Malawi cichlids consume substrate and filter it out through their gill rakers to eat the mollusks that were in the substrate. Gill rakers are finger-like structures that line the gills of some fish to catch any food that might escape through their gills. Many cichlids are primarily herbivores , feeding on algae (e.g. Petrochromis ) and plants (e.g. Etroplus suratensis ). Small animals, particularly invertebrates , are only
10296-487: The warm hypersaline lakes where the members of the genera Alcolapia and Danakilia are found. Lake Abaeded in Eritrea encompasses the entire distribution of D. dinicolai , and its temperature ranges from 29 to 45 °C (84 to 113 °F). With the exception of the species from Cuba, Hispaniola, and Madagascar, cichlids have not reached any oceanic island and have a predominantly Gondwanan distribution, showing
10400-539: The wrasses ( Labridae ), in the order Perciformes , but molecular studies have contradicted this grouping. On the basis of fossil evidence, it first appeared in Argentina during the Early Eocene epoch, about 48.6 million years ago; however, molecular clock estimates have placed the family's origin as far back as 67 million years ago, during the late Cretaceous period. The closest living relative of cichlids
10504-663: Was built in 1988. Her operator was the Tanzania Railway Corporation Marine Division until 1997, when it became the Marine Services Company Limited . Songea plies weekly between Liuli and Nkhata Bay via Itungi and Mbamba Bay . The worst Lake disaster was the sinking of the MV ; Vipya in 1946, which resulted in 145 deaths. Wildlife found in and around Lake Malawi or Nyasa includes Nile crocodiles , hippopotamus , monkeys , and
10608-1269: Was revealed that approximately 50 litres of non radioactive material leaked into a local creek. Despite reports in local media of radioactive contamination the government conducted independent scientific tests on the local river system and found that there was no effect on the environment. The 25 km solo swim across Lake Malawi between Cape Ngomba and Senga Bay has been accomplished on 5 occasions by 16 swimmers 1992: Lewis Pugh 9hrs 52 minutes (UK/South Africa) and Otto Thanning (South Africa) 10hrs 5 minutes 2010: Abigail Brown (UK) 9hrs 45 minutes 2013: Milko van Gool (Netherlands) 8hrs 46 minutes and Kaitlin Harthoorn (US) 9hrs 17 minutes 2016: (current record) Jean Craven (South Africa), Robert Dunford (Kenya), Michiel Le Roux (South Africa), Samantha Whelpton (South Africa), Greig Bannatyne (South Africa), Haydn Von Maltitz (South Africa), Douglas Livingstone-Blevins (South Africa) 7hrs 53 mins 2019: Chris Stapley ( Eswatini ) and Jay Azran (South Africa) 8hrs 40 minutes, Andrew Stevens ( Australia ) 10hrs 50 minutes, and Ruth Azran (South Africa) 11hrs 8 minutes. That same year, Martin Hobbs (South Africa), became
10712-558: Was settled. Occasional flare-ups of conflict occurred during the 1990s and in the 21st century. In 2012, Malawi's oil exploration initiative brought the issue to the fore, with Tanzania demanding that exploration cease until the dispute was settled. In 1954, an agreement was signed between the British and the Portuguese making the middle of the lake their boundary with the exception of Chizumulu Island and Likoma Island , which were kept by
10816-520: Was temporally correlated with egg-spot formation. A short, interspersed, repetitive element was also seen to be associated with egg spots. Specifically, it was evident upstream of the transcriptional start site of fhl2 in only Haplochrominis species with egg spots The cichlid Benitochromis nigrodorsalis from Western Africa ordinarily undergoes biparental reproduction, but is also able to undergo facultative (optional) selfing ( self-fertilization ). Facultative selfing may be an adaptive option when
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