Lake Tanganyika

Lake Tanganyika is situated within the Albertine Rift, the western branch of the East African Rift, and is confined by the mountainous walls of the valley. It is the largest rift lake in Africa and the second-largest freshwater lake by volume in the world. It is the deepest lake in Africa and holds the greatest volume of fresh water on the continent, accounting for 16% of the world's available fresh water. It extends for {{cvt|676|km|mi}} in a general north–south direction and averages {{cvt|50|km|mi}} in width. The lake covers {{cvt|32000|km2|sqmi}}, with a shoreline of {{cvt|1900|km|mi}}, a mean depth of {{cvt|572|m|ft}} and a maximum depth of {{cvt|1471|m|ft}} (in the northern basin). It holds an estimated {{cvt|18750|km3|cumi}} of water.{{cite web |url=http://www.ilec.or.jp/database/afr/dafr06.html |title=Datbase Summary: Lake Tanganyika |website=ilec.or.jp |access-date=2008-03-14 |url-status=dead |archive-url=https://web.archive.org/web/19991110092358/http://www.ilec.or.jp/database/afr/dafr06.html |archive-date=1999-11-10 |publisher=International Lake Environment Committee Foundation |place=Japan}}

The catchment area of the lake is {{cvt|231000|km2|mi2}}. Two main rivers flow into the lake, as well as numerous smaller rivers and streams (whose lengths are limited by the steep mountains around the lake). The one major outflow is the Lukuga River, which empties into the Congo River drainage. Precipitation and evaporation play a greater role than the rivers. At least 90% of the water influx is from rain falling on the lake's surface and at least 90% of the water loss is from direct evaporation.{{cite journal |last1=Kullander |first1=S.O. |author1-link=Sven O. Kullander |first2=T.R. |last2=Roberts |year=2011 |title=Out of Lake Tanganyika: endemic lake fishes inhabit rapids of the Lukuga River |journal=Ichthyol. Explor. Freshwaters |volume=22 |issue=4 |pages=355–76}}

The major river flowing into the lake is the Ruzizi River, formed about 10,000 years ago, which enters the north of the lake from Lake Kivu.{{Cite book |title=Natural Wonders of the World |publisher=Reader's Digest Association, Inc |year=1980 |isbn=978-0-89577-087-5 |editor-last=Scheffel |editor-first=Richard L. |location=US |pages=366–67 |editor-last2=Wernet |editor-first2=Susan J.}} The Malagarasi River, which is Tanzania's second largest river, enters the east side of Lake Tanganyika. The Malagarasi is older than Lake Tanganyika, and before the lake was formed, it probably was a headwater of the Lualaba River, the main Congo River headstream.

The lake has a complex history of changing flow patterns, due to its high altitude, great depth, slow rate of refill, and mountainous location in a turbulently volcanic area that has undergone climate changes. Apparently, it has rarely in the past had an outflow to the sea. It has been described as "practically endorheic" for this reason. The lake's connection to the sea is dependent on a high water level allowing water to overflow out of the lake through the Lukuga River into the Congo. When not overflowing, the lake's exit into the Lukuga River typically is blocked by sand bars and masses of weed, and instead this river depends on its own tributaries, especially the Niemba River, to maintain a flow.

The lake may also have at times had different inflows and outflows; inward flows from a higher Lake Rukwa, access to Lake Malawi and an exit route to the Nile have all been proposed to have existed at some point in the lake's history.{{cite book |last=Lévêque |first=Christian |title=Biodiversity Dynamics and Conservation: The Freshwater Fish of Tropical Africa |isbn=978-0521570336 |year=1997 |publisher=Cambridge University Press |page=110}}

Lake Tanganyika is an ancient lake, one of only twenty more than a million years old. Its three basins, which in periods with much lower water levels were separate lakes, are of different ages. The central began to form 9–12 million years ago (Mya), the northern 7–8 Mya and the southern 2–4 Mya.{{cite journal |last1=Cohen |last2=Soreghan |last3=Scholz |year=1993 |title=Estimating the age of formation of lakes: An example from Lake Tanganyika, East African Rift system |journal=Geosciences |volume=21 |issue=6 |pages=511–514 |doi=10.1130/0091-7613(1993)021<0511:ETAOFO>2.3.CO;2 |bibcode=1993Geo....21..511C}}

File:Clear lake Kagongo Ward.jpg

The lake's water is alkaline with a pH around 9 at depths of {{cvt|0-100|m|ft|-1}}.{{cite journal |last1=De |first1=Wever |last2=Muylaert |last3=der Gucht |first3=Van |last4=Pirlot |last5=Cocquyt |last6=Descy |last7=Plisnier |last8=Vyverman |year=2005 |title=Bacterial Community Composition in Lake Tanganyika: Vertical and Horizontal Heterogeneity |journal=Appl Environ Microbiol |volume=71 |issue=9 |pages=5029–5037 |doi=10.1128/AEM.71.9.5029-5037.2005 |pmid=16151083 |pmc=1214687 |bibcode=2005ApEnM..71.5029D}} Below this, it is around 8.7, gradually decreasing to 8.3–8.5 in the deepest parts of Tanganyika. A similar pattern can be seen in the electric conductivity, ranging from about 670 μS/cm in the upper part to 690 μS/cm in the deepest.

Surface temperatures generally range from about {{cvt|24|C|F}} in the southern part of the lake in early August to {{cvt|28|-|29|C|F}} in the late rainy season in March—April.{{cite journal |last1=Edmond |last2=Stallard |last3=Craigh |last4=Weiss |last5=Coulter |year=1993 |title=Nutrient chemistry of the water column of Lake Tanganyika |journal=Limnol. Oceanogr. |volume=38 |issue=4 |pages=725–738 |doi=10.4319/lo.1993.38.4.0725 |bibcode=1993LimOc..38..725E |doi-access=free}} At depths greater than {{cvt|400|m|ft}}, the temperature is very stable at {{cvt|23.1|-|23.4|C|F}}.{{Cite journal |last1=O'Reilly |first1=Catherine M. |last2=Alin |first2=Simone R. |last3=Plisnier |first3=Pierre-Denis |last4=Cohen |first4=Andrew S. |last5=Mckee |first5=Brent A. |date=August 14, 2003 |title=Climate change decreases aquatic ecosystem productivity of Lake Tanganyika, Africa |doi=10.1038/nature01833 |pmid=12917682 |journal=Nature |volume=424 |issue=6950 |pages=766–768 |bibcode=2003Natur.424..766O |s2cid=1637315}} The water has gradually warmed since the 19th century and this has accelerated with global warming since the 1950s.{{cite web |author=Jensen, M.R. |title=Lake Tanganyika Fisheries Declining From Global Warming |url=https://uanews.arizona.edu/story/lake-tanganyika-fisheries-declining-global-warming |publisher=University of Arizona |date=8 August 2016 |access-date=5 March 2018 |archive-date=6 March 2018 |archive-url=https://web.archive.org/web/20180306085806/https://uanews.arizona.edu/story/lake-tanganyika-fisheries-declining-global-warming |url-status=live }}

The lake is stratified and seasonal mixing generally does not extend beyond depths of {{cvt|150|m|ft}}. The mixing mainly occurs as upwellings in the south and is wind-driven, but to a lesser extent, up- and downwellings also occur elsewhere in the lake.{{cite journal |last1=Lowe-McConnell |first1=R.H. |year=2003 |title=Recent research in the African Great Lakes: Fisheries, biodiversity and cichlid evolution |journal=Freshwater Forum |volume=20 |issue=1 |pages=4–64}} As a consequence of the stratification, the deep sections contain "fossil water".Hutter; Yongqi; and Chubarenko (2011). Physics of Lakes, volume 1: Foundation of the Mathematical and Physical Background. P. 11. {{ISBN|978-3-642-15178-1}}. This also means it has no oxygen (it is anoxic) in the deeper parts, essentially limiting fish and other aerobic organisms to the upper part. Some geographical variations are seen in this limit, but it is typically at depths around {{cvt|100|m|ft}} in the northern part of the lake and {{cvt|240-250|m|ft}} in the south.Wright, J.J.; and L.M. Page (2006). Taxonomic revision of Lake Tanganyikan Synodontis (Siluriformes: Mochokidae). Florida Mus. Nat. Hist. Bull. 46(4): 99–154.Lowe-McConnell, R.H. (1987). Ecological Studies in Tropical Fish Communities. {{ISBN|0-521-28064-8}}. The oxygen-devoid deepest sections contain high levels of toxic hydrogen sulfide and are essentially lifeless, except for bacteria.{{Cite journal |last1=Ryan |first1=Emily |last2=Todd |first2=Jonathan A. |last3=McGlue |first3=Michael |last4=Kimirei |first4=Ismael |last5=Soreghan |first5=Michael |title=Variation in Taphonomic Character of Shell Beds in Lake Tanganyika, Africa: Paleoenvironmental and Stratigraphic Implications of Shell Beds in Lakes |series=Geological Society of America Abstracts with Programs |date=2017 |publisher=Geological Society of America |doi=10.1130/abs/2017am-304608}}

Lake Tanganyika and its associated wetlands are home to Nile crocodiles (including famous giant Gustave), Zambian hinged terrapins, serrated hinged terrapins, and pan hinged terrapins (last species not in the lake itself, but in adjacent lagoons).Spawls, Howell, Drewes, and Ashe (2002). A Field Guide to the Reptiles of East Africa. Academic Press, London. {{ISBN|0-12-656470-1}}. Storm's water cobra, a threatened subspecies of banded water cobra that feeds mainly on fish, is only found in Lake Tanganyika, where it prefers rocky shores.{{Cite journal |title=Boulengerina annulata stormsi (Storm's water cobra). Attempted predation |author1-last=O'Shea |author1-first=Mark |author1-link=Mark O'Shea (herpetologist) |author2-last=Mcintyre |author2-first=P.B. |journal=Herpetological Review |volume=36 |issue=2 |page=189 |date=2005 |url=http://www.markoshea.info/oba4-3_zambia_tanzania03.php |access-date=2023-03-11 |archive-date=2 December 2017 |archive-url=https://web.archive.org/web/20171202071348/http://www.markoshea.info/oba4-3_zambia_tanzania03.php |url-status=live }}

File:Murky waters.jpg

File:Neolamprologus brichardi.jpg. The complex behaviors of this species and its close relative N. pulcher have been studied in detail{{cite journal |last1=Dierkesa |last2=Taborskya |last3=Kohler |year=1999 |title=Reproductive parasitism of broodcare helpers in a cooperatively breeding fish |journal=Behavioral Ecology |volume=10 |issue=5 |pages=510–515 |doi=10.1093/beheco/10.5.510 |doi-access=free}}{{cite journal |last1=Balshine-Earn |last2=Lotem |year=1998 |title=Individual recognition in a cooperatively breeding cichlid : Evidence from video playback experiments |journal=Behaviour |volume=135 |issue=3 |pages=369–386 |doi=10.1163/156853998793066221}}{{cite journal |last1=Wernera |last2=Balshineb |last3=Leachc |last4=Lotem |year=2003 |title=Helping opportunities and space segregation in cooperatively breeding cichlids |doi=10.1093/beheco/arg067 |journal=Behavioral Ecology |volume=14 |issue=6 |pages=749–756 |doi-access=free}}]]

Lake Tanganyika is home to at least 250 endemic species of cichlids,{{Cite web |website=IW:LEARN {{pipe}} Documents |author1=Kelly West |title=Results and Experiences of the UNDP/GEF Conservation Initiative (RAF/92/G32) in Burundi, D.R. Congo, Tanzania, and Zambia |url=https://iwlearn.net/documents/6644 |access-date=2023-03-11 |date=28 February 2001 |archive-date=11 March 2023 |archive-url=https://web.archive.org/web/20230311162707/https://iwlearn.net/documents/6644 |url-status=live }} and undescribed species likely remain to be discovered.{{Cite web |title=Lake Tanganyika and its Diverse Cichlids |url=https://www.cichlid-forum.com/threads/lake-tanganyika-and-its-diverse-cichlids.456196/ |access-date=2023-03-11 |website=Cichlid Fish Forum |date=24 December 2009 |author1=Craig Mortiff |archive-date=11 March 2023 |archive-url=https://web.archive.org/web/20230311162711/https://www.cichlid-forum.com/threads/lake-tanganyika-and-its-diverse-cichlids.456196/ |url-status=live }} Almost all (roughly 98%) of the lake's cichlid species are found solely there, and nowhere else, thus making it a precious biological resource for the study of speciation and evolution.{{cite journal |last1=Takahashi |first1=T. |last2=Hori |first2=M. |year=2012 |title=Genetic and Morphological Evidence Implies Existence of Two Sympatric Species in Cyathopharynx furcifer (Teleostei: Cichlidae) from Lake Tanganyika |journal=International Journal of Evolutionary Biology |volume=2012 |page=980879 |doi=10.1155/2012/980879 |pmid=22675655 |pmc=3363988 |doi-access=free}}{{cite journal |last1=Kornfield |first1=Ivy |last2=Smith |first2=Peter A |year=2000 |title=African Cichlid Fishes: Model Systems for Evolutionary Biology |journal=Annual Review of Ecology and Systematics |volume=31 |pages=163–196 |doi=10.1146/annurev.ecolsys.31.1.163}} The cichlids of the African Great Lakes, including Tanganyika, represent the most diverse extent of adaptive radiation in vertebrates. Some of the endemic species do occur slightly into the upper Lukuga River (Lake Tanganyika's outflow), but any further distribution into the Congo River basin is stemmed purely by geography and chemistry—Tanganyika's lake environment is far more stable and consistent than the rapids and fast-flowing sections of the Congo River. Additionally, Lake Tanganyika's water is alkaline and of a higher pH (which the cichlids prefer), containing a higher calcium and mineral content than the Congo's acidic, sediment-rich waters, which collect much organic detritus from the surrounding rainforests. In areas of the Congo away from rapids or whitewater, the accumulated sediment and organic matter creates sections of "blackwater", with a high concentration of tannins from dissolving wood and leaves, creating an environment in which cichlids simply do not thrive. Likewise, many tropical riverine species would likely suffer if exposed to the crisp, alkaline lake water.

Although Lake Tanganyika has fewer cichlid species than Lakes Malawi or Victoria—which both have experienced relatively recent explosive species radiations (resulting in many closely related species)—,{{cite journal |last1=Turner |first1=Seehausen |last2=Knight |first2=Allender |last3=Robinson |year=2001 |title=How many species of cichlid fishes are there in African lakes? |doi=10.1046/j.1365-294x.2001.01200.x |journal=Molecular Ecology |volume=10 |issue=3 |pages=793–806 |pmid=11298988 |bibcode=2001MolEc..10..793T |s2cid=12925712 |doi-access=free}} its cichlids are the most morphologically and genetically diverse.{{Cite journal |last1=Meyer |last2=Matchiner |last3=Salburger |first1=Britta |first2=Michael |first3=Walter |date=25 November 2013 |title=A tribal level phylogeny of Lake Tanganyika cichlid fishes based on a genomic multi-marker approach |journal=Molecular Phylogenetics and Evolution |doi=10.1016/j.ympev.2014.10.009 |pmid=25433288 |volume=83 |pages=56–71 |pmc=4334724}}{{Cite journal |last=Seehausen |first=O. |year=2015 |title=Process and pattern in cichlid radiations – inferences for understanding unusually high rates of evolutionary diversification |journal=New Phytologist |doi=10.1111/nph.13450 |volume=207 |issue=2 |pages=304–312 |pmid=25983053 |doi-access=free}} This is linked to the maturity of Tanganyika, as it is far older than the other lakes.{{cite journal |last1=Nishida |first1=M |year=1991 |title=Lake Tanganyika as an evolutionary reservoir of old lineages of East African cichlid fishes: Inferences from allozyme data |journal=Experientia |volume=47 |issue=9 |pages=974–979 |doi=10.1007/bf01929896 |s2cid=37599331}} Tanganyika has the largest number of endemic cichlid genera of all African lakes. All Tanganyika cichlids are in the subfamily Pseudocrenilabrinae. Of the 10 tribes in this subfamily, half are largely or entirely restricted to the lake (Cyprichromini, Ectodini, Lamprologini, Limnochromini and Tropheini), while another three have species in the lake (Haplochromini, Tilapiini and Tylochromini).{{cite journal |last1=Sparks |last2=Smith |year=2004 |title=Phylogeny and biogeography of cichlid fishes (Teleostei: Perciformes: Cichlidae) |journal=Cladistics |volume=20 |issue=6 |pages=501–517 |doi=10.1111/j.1096-0031.2004.00038.x |pmid=34892958 |citeseerx=10.1.1.595.2118 |s2cid=36086310}} Others have proposed splitting the Tanganyika cichlids into as many as 12–16 tribes (Bathybatini, Benthochromini, Boulengerochromini, Cyphotilapiini, Eretmodini, Greenwoodochromini, Perissodini and Trematocarini, in addition to the aforementioned tribes).

Most Tanganyika cichlids live along the shoreline, down to a depth of {{cvt|100|m|ft|-1}}, but some deep-water species regularly descend to {{cvt|200|m|ft|-1}}.{{cite journal |last1=Kirchberger |last2=Sefc |last3=Sturmbauer |last4=Koblmuller |year=2012 |title=Evolutionary History of Lake Tanganyika's Predatory Deepwater Cichlids |journal=International Journal of Evolutionary Biology |volume=2012 |pages=716209 |doi=10.1155/2012/716209 |pmid=22675652 |pmc=3362839 |doi-access=free}} Trematocara species have, exceptionally, been found at more than {{cvt|300|m|ft|-1}}, which is deeper than any other cichlid known.Loiselle, Paul (1994). The Cichlid Aquarium, p. 304. Tetra Press, Germany. {{ISBN|978-1564651464}}. Some of the deepwater genera (e.g., Bathybates, Gnathochromis, Hemibates and Xenochromis) have been caught in places virtually devoid of oxygen, and how they are able to survive there is unclear. Tanganyika cichlids are generally benthic (found at or near the bottom) and/or coastally.Lindqvist, O.V.; H. Mölsä; K. Solonen; J. Sarvala, editors (1999). From Limnology to Fisheries: Lake Tanganyika and Other Large Lakes. pp. 213–214. Springer. {{ISBN|978-0792360179}} No Tanganyika cichlids are truly pelagic and offshore, except for some of the piscivorous Bathybates. Two of these, B. fasciatus and B. leo, mainly feed on Tanganyika sardines. Tanganyika cichlids differ extensively in ecology, and include species that are herbivores, detritivores, planktivores, insectivores, molluscivores, scavengers, scale-eaters and piscivores. These dietary specializations, however, have been shown to be variable and subject to opportunistic changes. That is, many species of Tanganyikan cichlid with specialized diets showed opportunistic, episodic exploitation of Stolothrissa tanganicae and Limnothrissa miodon when prey concentrations were unusually high.{{Cite journal |vauthors=Golcher-Benavides J, Wagner CE |title=Playing out Liem's Paradox: Opportunistic Piscivory across Lake Tanganyikan Cichlids |journal=The American Naturalist |year=2019 |volume=194 |issue=2 |pages=260–267 |doi=10.1086/704169 |pmid=31318283 |s2cid=155438716}} The fishes' breeding behavior falls into two main groups: the substrate- or sand-spawners (often in caves or rock crevices) and the mouthbrooders.Schliewen, U. (1992). Aquarium Fish. Barron's Educational Series. {{ISBN|978-0812013504}}. Among the endemic species are two of the world's smallest cichlids, Neolamprologus multifasciatus and N. similis (both shell dwellers), measuring up to {{cvt|4-5|cm|in}},{{FishBase | genus = Neolamprologus | species = multifasciatus | month = March| year = 2017}}{{FishBase | genus = Neolamprologus | species = similis | month = March| year = 2017}} and one of the largest, the giant cichlid (Boulengerochromis microlepis) at up to {{cvt|90|cm|ft}}.{{cite web |url=http://www.practicalfishkeeping.co.uk/features/articles/the-10-biggest-cichlids |title=The 10 biggest cichlids |publisher=Practical Fishkeeping |date=13 June 2016 |access-date=17 March 2017 |archive-date=20 March 2017 |archive-url=https://web.archive.org/web/20170320052647/http://www.practicalfishkeeping.co.uk/features/articles/the-10-biggest-cichlids |url-status=live }}

Many cichlids from Lake Tanganyika, such as species from the genera Altolamprologus, Cyprichromis, Eretmodus, Julidochromis, Lamprologus, Neolamprologus, Tropheus and Xenotilapia, are popular aquarium fish due to their bright colors and patterns, and interesting behaviors. Recreating a Lake Tanganyika biotope to host those cichlids in a habitat similar to their natural environment is also popular in the aquarium hobby, with many species today being bred in captivity successfully.{{cite web |url=http://www.aquariumslife.com/featured/lake-tanganyika-biotope/ |title=tanganyika biotope aquarium |date=2010-02-10 |publisher=Aquariums Life |archive-url=https://web.archive.org/web/20120302102920/http://www.aquariumslife.com/featured/lake-tanganyika-biotope/ |archive-date=2012-03-02 |url-status=usurped |access-date=2014-02-03}}

File:Bathybates ferox.jpg|Bathybatini (E): Bathybates ferox is benthic and piscivorous, but the genus also includes pelagic species. The tribe is sometimes split in three, others being Hemibatini and Trematocarini{{Cite journal |last1=Meyer |last2=Matchiner |last3=Salburger |year=2015 |title=Lake Tanganyika—A 'Melting Pot' of Ancient and Young Cichlid Lineages (Teleostei: Cichlidae)? |journal=PLOS ONE |volume=10 |issue=7 |doi=10.1371/journal.pone.0125043 |pmid=25928886 |page=e0125043 |pmc=4415804 |bibcode=2015PLoSO..1025043W |doi-access=free}}{{Cite journal |last1=Weiss |last2=Cotterill |last3=Schliewen |year=2015 |title=A tribal level phylogeny of Lake Tanganyika cichlid fishes based on a genomic multi-marker approach |journal=Molecular Phylogenetics and Evolution |volume=83 |pages=56–71 |doi=10.1016/j.ympev.2014.10.009 |pmid=25433288 |pmc=4334724}}

File:Benthochromis tricoti.jpg|Benthochromini (E): Benthochromis horii was scientifically described in 2008, but has often been misidentifed as B. tricoti{{cite journal |title=Description of a new cichlid fish species of the genus Benthochromis (Perciformes: Cichlidae) from Lake Tanganyika |last1=Takahashi |journal=Journal of Fish Biology |volume=72 |issue=3 |pages=603–613 |year=2008 |doi=10.1111/j.1095-8649.2007.01727.x |first1=T.|bibcode=2008JFBio..72..603T }}

File:DKoehl Boulengerochromis microlepis.jpg|Boulengerochromini (E): Boulengerochromis microlepis is one of the world's largest cichlids and only member of its tribe

File:Cyphotilapia frontosa2.jpg|Cyphotilapiini (E): Cyphotilapia frontosa, one of only two similar species in the tribe{{cite journal |last1=Takahashi |first1=T. |last2=Nakaya |first2=K. |year=2003 |title=New species of Cyphotilapia (Perciformes: Cichlidae) from Lake Tanganyika, Africa |journal=Copeia |volume=2003 |issue=4 |pages=824–832 |doi=10.1643/ia03-148.1 |s2cid=83854866}}

File:Kleinschuppiger Kaerpflingsbuntbarsch Cyprichromis microlepidotus Tierpark Hellabrunn-1.jpg|Cyprichromini (E): Cyprichromis microlepidotus and other members of this tribe are open-water planktivores{{cite iucn |author=Bigirimana, C. |date=2006 |title=Cyprichromis microlepidotus |volume=2006 |page=e.T60487A12363286 |doi=10.2305/IUCN.UK.2006.RLTS.T60487A12363286.en |access-date=13 November 2021}}Smith, M.P. (1998). Lake Tanganyikan Cichlids, pp. 9–10. {{ISBN|0-7641-0615-5}}

File:Ophthalmotilapia nasuta Kipili.jpg|Ectodini (E): Ophthalmotilapia nasuta (male) is sexually dimorphic, males being more colorful with longer fins and nose{{Cite web |title=Ophthalmotilapia nasuta |website=Seriously Fish |url=https://www.seriouslyfish.com/species/ophthalmotilapia-nasuta/ |access-date=2023-03-11 |archive-date=11 March 2023 |archive-url=https://web.archive.org/web/20230311162708/https://www.seriouslyfish.com/species/ophthalmotilapia-nasuta/ |url-status=live }}

File:Eretmodus-sp-kavala1.jpg|Eretmodini (E): Eretmodus cyanostictus lives near the bottom in the turbulent, coastal surf zone,{{FishBase | genus = Eretmodus | species = cyanostictus | month = April| year = 2017}} like other members of its tribe

File:Astatotilapia burtoni.png|Haplochromini: Astatotilapia burtoni is one of the few Tanganyika species, unlike other African Great Lakes where most belong to this tribe{{cite journal |last1=Lowe-McConnell |first1=R |year=2009 |title=Fisheries and cichlid evolution in the African Great Lakes: progress and problems |journal=Freshwater Reviews |volume=2 |issue=2 |pages=131–151 |doi=10.1608/frj-2.2.2 |s2cid=54011001}}

File:Schachbrett-Schlankcichlide.jpg|Lamprologini (E): Julidochromis marlieri is popular in the aquarium trade where members of the genus are known as "Julies"{{Cite web |title=Julidochromis marlieri (Marlier's Julie) |website=Seriously Fish |url=https://www.seriouslyfish.com/species/julidochromis-marlieri/ |access-date=2023-03-11 |archive-date=11 March 2023 |archive-url=https://web.archive.org/web/20230311162711/https://www.seriouslyfish.com/species/julidochromis-marlieri/ |url-status=live }}

File:Gnathochromis premaxillaris.jpg|Limnochromini (E): Gnathochromis permaxillaris is a zooplanktivore with an unusual protractile mouth{{cite iucn |author=Bigirimana, C. |date=2006 |title=Gnathochromis permaxillaris |volume=2006 |page=e.T60493A12364587 |doi=10.2305/IUCN.UK.2006.RLTS.T60493A12364587.en |access-date=13 November 2021}}

File:Perissodus microlepis juvenile in aquarium.jpg|Perissodini (E): Perissodus microlepis, a specialized scale-eating species{{cite journal |last1=Stewart |first1=T.A. |last2=Albertson |first2=R.C. |year=2010 |title=Evolution of a unique predatory feeding apparatus: functional anatomy, development and a genetic locus for jaw laterality in Lake Tanganyika scale-eating cichlids |journal=BMC Biology |volume=8 |issue=1 |page=8 |doi=10.1186/1741-7007-8-8 |pmid=20102595 |pmc=2828976 |doi-access=free}}

File:Oreochromis tanganicae (Günther).jpg|Tilapiini: Oreochromis tanganicae is one of the most common coastal species found in local fish markets{{cite iucn |author=Ntakimazi, G. |date=2006 |title=Oreochromis tanganicae |volume=2006 |page=e.T60625A12387918 |doi=10.2305/IUCN.UK.2006.RLTS.T60625A12387918.en |access-date=13 November 2021}}

File:TropheusspRed200.jpg|Tropheini (E): Tropheus moorii ("red" Chimba morph) is highly variable and the taxonomy of some of the morphs is questionableBegon, M.; and A.H. Fitter (1995). Advances in Ecological Research, vol. 26, p. 203. {{ISBN|0-12-013926-X}}{{cite journal |last1=Salzburger |last2=Niederstätter |last3=Brandstätter |last4=Berger |last5=Parson |last6=Snoeks |last7=Sturmbauer |year=2006 |title=Colour-assortative mating among populations of Tropheus moorii, a cichlid fish from Lake Tanganyika, East Africa |journal=Proc Biol Sci |volume=273 |issue=1584 |pages=257–266 |doi=10.1098/rspb.2005.3321 |pmid=16543167 |pmc=1560039}}{{Cite web |title=Tropheus Genus Evolution |url=http://www.cichlidworld.eu/clanky/evolucia_tropheus_e.htm |access-date=2023-03-11 |website=Cichlid World |author1=Robert Toman |date=2017 |archive-date=19 September 2021 |archive-url=https://web.archive.org/web/20210919232102/http://www.cichlidworld.eu/clanky/evolucia_tropheus_e.htm |url-status=dead }}

File:Lamprichthys tanganicanus.JPG (Lamprichthys tanganicanus) is the only member of its genus{{FishBase genus | genus = Lamprichthys | month = March| year = 2017}}]]

Lake Tanganyika is home to more than 80 species of non-cichlid fish and about 60% of these are endemic.{{cite journal |last1=Brown |last2=Britz |last3=Bills |last4=Rüber |last5=Day |year=2011 |title=Pectoral fin loss in the Mastacembelidae: a new species from Lake Tanganyika |journal=Journal of Zoology |volume=284 |issue=4 |pages=286–293 |doi=10.1111/j.1469-7998.2011.00804.x}}{{cite journal |last1=Wright |first1=J.J. |last2=Bailey |first2=R.M. |year=2012 |title=Systematic revision of the formerly monotypic genus Tanganikallabes (Siluriformes: Clariidae) |url=https://deepblue.lib.umich.edu/bitstream/2027.42/91200/1/j.1096-3642.2011.00789.x.pdf |journal=Zoological Journal of the Linnean Society |volume=165 |issue=1 |pages=121–142 |doi=10.1111/j.1096-3642.2011.00789.x |doi-access=free}}

The open waters of the pelagic zone are dominated by four non-cichlid species: Two species of "Tanganyika sardine" (Limnothrissa miodon and Stolothrissa tanganicae) form the largest biomass of fish in this zone, and they are important prey for the forktail lates (Lates microlepis) and sleek lates (L. stappersii). Two additional lates are found in the lake, the Tanganyika lates (L. angustifrons) and bigeye lates (L. mariae), but both these are primarily benthic hunters, although they also may move into open waters. The four lates, all endemic to Tanganyika, have been overfished and larger individuals are rare today.

Among the more unusual fish in the lake are the endemic, facultatively brood parasitic "cuckoo catfish", including at least Synodontis grandiops{{Cite web |title=Synodontis grandiops • Mochokidae |date=2020 |url=https://www.planetcatfish.com/common/species.php?species_id=710 |access-date=2023-03-11 |website=www.planetcatfish.com |language=en-gb |archive-date=1 April 2017 |archive-url=https://web.archive.org/web/20170401232617/https://www.planetcatfish.com/common/species.php?species_id=710 |url-status=live }} and S. multipunctatus. A number of others are very similar (e.g., S. lucipinnis and S. petricola) and have often been confused; it is unclear if they have a similar behavior.{{Cite web |title=Synodontis lucipinnis • Mochokidae |date=2023 |url=https://www.planetcatfish.com/common/species.php?task=&species_id=103 |access-date=2023-03-11 |website=www.planetcatfish.com |language=en-gb |archive-date=1 April 2017 |archive-url=https://web.archive.org/web/20170401232507/https://www.planetcatfish.com/common/species.php?task=&species_id=103 |url-status=live }}{{pb}}{{Cite web |title=Synodontis petricola • Mochokidae |date=2023 |url=https://www.planetcatfish.com/common/species.php?task=&species_id=857 |access-date=2023-03-11 |website=www.planetcatfish.com |language=en-gb |archive-date=1 April 2017 |archive-url=https://web.archive.org/web/20170401232823/https://www.planetcatfish.com/common/species.php?task=&species_id=857 |url-status=live }} The facultative brood parasites often lay their eggs synchronously with mouthbroding cichlids. The cichlid pick up the eggs in their mouth as if they were their own. Once the catfish eggs hatch the young eat the cichlid eggs. Six catfish genera are entirely restricted to the lake basin: Bathybagrus, Dinotopterus, Lophiobagrus, Phyllonemus, Pseudotanganikallabes and Tanganikallabes.{{Cite web |title=Species in the Tanganyika |url=https://www.fishbase.se/TrophicEco/FishEcoList.php?ve_code=4 |access-date=2023-03-11 |type=table |website=www.fishbase.se |archive-date=11 March 2023 |archive-url=https://web.archive.org/web/20230311162720/https://www.fishbase.se/TrophicEco/FishEcoList.php?ve_code=4 |url-status=live }}{{cite journal |author=Wright, J.J. |year=2017 |title=A new diminutive genus and species of catfish from Lake Tanganyika (Siluriformes: Clariidae) |journal=J Fish Biol |doi=10.1111/jfb.13374 |volume=91 |issue=3 |pages=789–805 |pmid=28744868|bibcode=2017JFBio..91..789W }} Although not endemic on a genus level, six species of Chrysichthys catfish are only found in the Tanganyika basin where they live both in shallow and relatively deep waters; in the latter habitat they are the primary predators and scavengers. A unique evolutionary radiation in the lake is the 15 species of Mastacembelus spiny eels, all but one endemic to its basin.{{cite journal |last1=Brown |last2=Rüber |last3=Bills |last4=Day |year=2010 |title=Mastacembelid eels support Lake Tanganyika as an evolutionary hotspot of diversification |journal=BMC Evolutionary Biology |volume=10 |page=188 |doi=10.1186/1471-2148-10-188 |pmid=20565906 |pmc=2903574 |doi-access=free}} Although other African Great Lakes have Synodontis catfish, endemic catfish genera and Mastacembelus spiny eels, the relatively high diversity is unique to Tanganyika, which likely is related to its old age.

Among the non-endemic fish, some are widespread African species but several are only shared with the Malagarasi and Congo River basins, such as the Congo bichir (Polypterus congicus), goliath tigerfish (Hydrocynus goliath), Citharinus citharus, six-banded distichodus (Distichodus sexfasciatus) and mbu puffer (Tetraodon mbu).

File:Tiphobia horei 01.JPG with its elaborate shape and spines.]]

A total of 83 freshwater snail species (65 endemic) and 11 bivalve species (8 endemic) are known from the lake.{{cite book |editor1=Darwall, W. |editor2=Smith, K. |editor3=Allen, D. |editor4=Holland, R. |editor5=Harrison, I. |editor6=Brooks, E. |year=2011 |journal=The Diversity of Life in African Freshwaters: Under Water, Under Threat. An Analysis of the Status and Distribution of Freshwater Species Throughout Mainland Africa |author1=Seddon, M. |author2=Appleton, C. |author3=Van Damme, D. |author4=Graf, D. |title=Freshwater molluscs of Africa: diversity, distribution, and conservation |publisher=IUCN |pages=92–119 |isbn=978-2831713458}} Among the endemic bivalves are three monotypic genera: Grandidieria burtoni, Pseudospatha tanganyicensis and Brazzaea anceyi. Many of the snails are unusual for species living in freshwater in having noticeably thickened shells and/or distinct sculpture, features more commonly seen in marine snails. They are referred to as thalassoids, which can be translated to "marine-like".Brown, D. (1994). Freshwater Snails Of Africa And Their Medical Importance. 2nd edition. {{ISBN|0-7484-0026-5}} All the Tanganyika thalassoids, which are part of Prosobranchia, are endemic to the lake. Initially they were believed to be related to similar marine snails, but they are now known to be unrelated. Their appearance is now believed to be the result of the highly diverse habitats in Lake Tanganyika and evolutionary pressure from snail-eating fish and, in particular, Platythelphusa crabs.{{cite journal |last1=West |first1=K. |last2=Cohen |first2=A. |year=1996 |title=Shell microstructure of gastropods from Lake Tanganyika, Africa: adaptation, convergent evolution, and escalation. |journal=Evolution |volume=50 |issue=2 |pages=672–682 |doi=10.2307/2410840 |jstor=2410840 |pmid=28568935}} A total of 17 freshwater snail genera are endemic to the lake, such as Hirthia, Lavigeria, Paramelania, Reymondia, Spekia, Stanleya, Tanganyicia and Tiphobia. There are about 30 species of non-thalassoid snails in the lake, but only five of these are endemic, including Ferrissia tanganyicensis and Neothauma tanganyicense. The latter is the largest Tanganyika snail and its shell is often used by small shell-dwelling cichlids.{{cite journal |last1=Koblmüller |last2=Duftner |last3=Sefc |last4=Aibara |last5=Stipacek |last6=Blanc |last7=Egger |last8=Sturmbauer |year=2007 |title=Reticulate phylogeny of gastropod-shell-breeding cichlids from Lake Tanganyika — the result of repeated introgressive hybridization. |doi=10.1186/1471-2148-7-7 |journal=BMC Evolutionary Biology |volume=7 |page=7 |pmid=17254340 |pmc=1790888 |doi-access=free}}

Crustaceans are also highly diverse in Tanganyika with more than 200 species, of which more than half are endemic. They include 10 species of freshwater crabs (9 Platythelphusa and Potamonautes platynotus; all endemic),{{cite journal |last1=Marijnissen |last2=Michel |last3=Daniels |last4=Erpenbeck |last5=Menken |last6=Schram |year=2006 |title=Molecular evidence for recent divergence of Lake Tanganyika endemic crabs (Decapoda: Platythelphusidae) |journal=Molecular Phylogenetics and Evolution |volume=40 |issue=2 |pages=628–634 |doi=10.1016/j.ympev.2006.03.025 |pmid=16647274}} at least 11 species of small atyid shrimp (Atyella, Caridella and Limnocaridina),{{cite journal |last1=Fryer |first1=G |year=2006 |title=Evolution in ancient lakes: radiation of Tanganyikan atyid prawns and speciation of pelagic cichlid fishes in Lake Malawi. |doi=10.1007/s10750-006-0322-x |journal=Hydrobiologia |volume=568 |issue=1 |pages=131–142 |s2cid=44127332}} an endemic palaemonid shrimp (Macrobrachium moorei),{{cite iucn |author=De Grave, S. |date=2013 |title=Macrobrachium moorei |volume=2013 |page=e.T196882A2477768 |doi=10.2305/IUCN.UK.2013-1.RLTS.T196882A2477768.en |access-date=13 November 2021}} about 100 ostracods,{{cite journal |last1=Martens |last2=Schön |last3=Meisch |last4=Horne |year=2008 |title=Global diversity of ostracods (Ostracoda, Crustacea) in freshwater |journal=Hydrobiologia |volume=595 |pages=185–193 |doi=10.1007/s10750-007-9245-4 |s2cid=207150861}} including many endemics,{{cite journal |last1=Gitter |first1=F. |last2=Gross |first2=M. |last3=Piller |first3=W.E. |year=2015 |title=Sub-Decadal Resolution in Sediments of Late Miocene Lake Pannon Reveals Speciation of Cyprideis (Crustacea, Ostracoda) |journal=PLOS ONE |volume=10 |issue=4 |page=e0109360 |doi=10.1371/journal.pone.0109360 |pmid=25902063 |pmc=4406499 |bibcode=2015PLoSO..1009360G |doi-access=free}}{{cite journal |last1=Schön |first1=I. |last2=Martens |first2=K. |year=2012 |title=Molecular analyses of ostracod flocks from Lake Baikal and Lake Tanganyika |journal=Hydrobiologia |volume=682 |issue=1 |pages=91–110 |doi=10.1007/s10750-011-0935-6 |s2cid=14831643}} and several copepods.{{cite journal |last1=Cirhuza |first1=D.M. |last2=Plisnier |first2=P.-D. |year=2016 |title=Composition and seasonal variations in abundance of Copepod (Crustacea) populations from the northern part of Lake Tanganyika |url=https://orbi.uliege.be/handle/2268/248670 |journal=Aquatic Ecosystem Health & Management |volume=19 |issue=4 |pages=401–410 |doi=10.1080/14634988.2016.1251277 |hdl=2268/248670 |s2cid=90502032 |access-date=30 August 2020 |archive-date=22 July 2021 |archive-url=https://web.archive.org/web/20210722064916/https://orbi.uliege.be/handle/2268/248670 |url-status=live }} Among these, Limnocaridina iridinae lives inside the mantle cavity of the unionid mussel Pleiodon spekei, making it one of only two known commensal species of freshwater shrimp (the other is the sponge-living Caridina spongicola from Lake Towuti, Indonesia).{{cite journal |last1=De Grave |first1=S. |last2=Cai |first2=Y. |last3=Amnker |first3=A. |year=2008 |title=Global diversity of shrimps (Crustacea: Decapoda: Caridea) in freshwater |journal=Hydrobiologia |volume=595 |pages=287–293 |doi=10.1007/s10750-007-9024-2 |s2cid=22945163}}{{cite iucn |author=De Grave, S. |date=2013 |title=Limnocaridina iridinae |volume=2013 |page=e.T198058A2510158 |doi=10.2305/IUCN.UK.2013-1.RLTS.T198058A2510158.en |access-date=13 November 2021}}

Among Rift Valley lakes, Lake Tanganyika far surpasses all others in terms of crustacean and freshwater snail richness (both in total number of species and number of endemics).Segers, H.; and Martens, K; editors (2005). The Diversity of Aquatic Ecosystems. p. 46. Developments in Hydrobiology. Aquatic Biodiversity. {{ISBN|1-4020-3745-7}} For example, the only other Rift Valley lake with endemic freshwater crabs are Lake Kivu and Lake Victoria with two species each.Cumberlidge, N.; and Meyer, K. S. (2011). [http://commons.nmu.edu/cgi/viewcontent.cgi?article=1029&context=facwork_journalarticles A revision of the freshwater crabs of Lake Kivu, East Africa.] {{Webarchive|url=https://web.archive.org/web/20140725112334/http://commons.nmu.edu/cgi/viewcontent.cgi?article=1029&context=facwork_journalarticles |date=25 July 2014 }} Journal Articles. Paper 30.{{cite journal |last1=Cumberlidge |first1=N. |last2=Clark |first2=P.F. |year=2017 |title=Description of three new species of Potamonautes MacLeay, 1838 from the Lake Victoria region in southern Uganda, East Africa (Brachyura: Potamoidea: Potamonautidae) |journal=European Journal of Taxonomy |issue=371 |pages=1–19 |doi=10.5852/ejt.2017.371 |doi-access=free|hdl=10141/622400 |hdl-access=free }}

The diversity of other invertebrate groups in Lake Tanganyika is often not well-known, but there are at least 20 described species of leeches (12 endemics),Segers, H.; and Martens, K; editors (2005). The Diversity of Aquatic Ecosystems. p. 44. Developments in Hydrobiology. Aquatic Biodiversity. {{ISBN|1-4020-3745-7}} 9 sponges (7 endemic), 6 bryozoa (2 endemic), 11 flatworms (7 endemic), 20 nematodes (7 endemic), 28 annelids (17 endemic) and the small hydrozoan jellyfish Limnocnida tanganyicae.Salonen; Högmander; Langenberg; Mölsä; Sarvala; Tarvainen; and Tiirola (2012). Limnocnida tanganyicae medusae (Cnidaria: Hydrozoa): a semiautonomous microcosm in the food web of Lake Tanganyika. Hydrobiologia 690(1): 97–112.

File:Fishing boat in Kagongo Ward.jpg

File:Fisherman on Lake Tanganyika.jpg

Lake Tanganyika supports a major fishery, which, depending on source, provides 25–40%{{cite web |url=http://www.mongabay.com/external/lake_tanganyika_warming.htm |title=Global warming is killing off tropical lake fish – Study of Lake Tanganyika |publisher=www.mongabay.com |access-date=2008-03-14 |archive-date=29 June 2015 |archive-url=https://web.archive.org/web/20150629225857/http://www.mongabay.com/external/lake_tanganyika_warming.htm |url-status=live }} or {{circa}} 60% of the animal protein in the diet of the people living in the region.{{cite news |author=McGrath, M. |title=Decline of fishing in Lake Tanganyika 'due to warming' |url=https://www.bbc.com/news/science-environment-37009305 |publisher=BBC |date=8 August 2016 |access-date=5 March 2018 |archive-date=28 April 2018 |archive-url=https://web.archive.org/web/20180428163551/http://www.bbc.com/news/science-environment-37009305 |url-status=live }}

Lake Tanganyika fish can be found exported throughout East Africa. Major commercial fishing began in the mid-1950s and has, together with global warming, had a heavy impact on the fish populations, causing significant declines. In 2016, it was estimated that the total catch was up to 200,000 tonnes.

File:Stanley's Lake Tanganyika.jpg's route.]]

It is thought that early Homo sapiens were making an impact on the region during the Stone Age. The time period of the Middle Stone Age to Late Stone Age is described as an age of advanced hunter-gatherers.{{Cite book |title=East African Ecosystems and Their Conservation |publisher=New York: Oxford University Press}}

There are many methods which the native people of the area used for fishing. Most of them included using a lantern as a lure for fish that are attracted to light. There were three basic forms. One called Lusenga which is a wide net used by one person from a canoe. The second one is using a lift net. This was done by dropping a net deep below the boat using two parallel canoes and then simultaneously pulling it up. The third is called Chiromila which consisted of three canoes. One canoe was stationary with a lantern while another canoe holds one end of the net and the other circles the stationary one to meet up with the net.{{Cite book |title=Lake Tanganyika and Its Life |publisher=Oxford Press |year=1991}}

The first known Westerners to find the lake were the British explorers Richard Burton and John Speke, in 1858. They located it while searching for the source of the Nile River. Speke continued and found the actual source, Lake Victoria. Later David Livingstone passed by the lake. He noted the name "Liemba" for its southern part, a word probably from the Fipa language.{{cite book |author=David Livingstone |title=The Last Journals of David Livingstone in Central Africa from 1865 to His Death |url=https://books.google.com/books?id=ZJRKJnFkJeIC&pg=PA212 |volume=1 |date=2008 |publisher=BiblioBazaar |isbn=978-0-554-26021-1 |page=338}} Tanganyika means "stars" in the Luvale language.{{ cite journal |title=An African Aesthetic |author=Daniel J. Crowley |journal=The Journal of Aesthetics and Art Criticism |volume=24 |issue=4 |date=Summer 1966 |pages=519–524 |publisher=Wiley |doi=10.2307/428776 |jstor=428776}}{{rp|523}}

The lake was the scene of Battle for Lake Tanganyika during World War I. With the aid of the Graf Goetzen, the Germans had complete control of the lake in the early stages of the war. The ship was used both to ferry cargo and personnel across the lake, and as a base from which to launch surprise attacks on Allied troops.Giles Foden: Mimi and Toutou Go Forth — The Bizarre Battle for Lake Tanganyika, Penguin, 2004. It therefore became essential for the Allied forces to gain control of the lake themselves. Under the command of Lieutenant Commander Geoffrey Spicer-Simson the British Royal Navy achieved the monumental task of bringing two armed motor boats HMS Mimi and HMS Toutou from England to the lake by rail, road and river to Albertville (since renamed Kalemie in 1971) on the western shore of Lake Tanganyika. The two boats waited until December 1915, and mounted a surprise attack on the Germans, with the capture of the gunboat Kingani. Another German vessel, the Hedwig, was sunk in February 1916, leaving the Götzen as the only German vessel remaining to control the lake. In order to avoid his prize ship falling into Allied hands, Zimmer scuttled the vessel on July 26, 1916. The vessel was later raised in 1924 and renamed MV Liemba.

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• {{Cite Collier's|wstitle=Tanganyika|short=x |noicon=x}}
• {{Cite NSRW |wstitle=Tanganyika |short=x |noicon=x}}
• {{Cite EB1911|wstitle=Tanganyika|short=x |noicon=x}}

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Category:Ancient lakes

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