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62-839: The Kihansi spray toad ( Nectophrynoides asperginis ) is a small toad endemic to Tanzania . The species is live-bearing and insectivorous. The Kihansi spray toad is currently categorized as Extinct in the Wild by the International Union for Conservation of Nature (IUCN), though the species persists in ex situ , captive breeding populations. The Kihansi spray toad is a small, sexually dimorphic anuran, with females reaching up to 2.9 cm (1.1 in) long and males up to 1.9 cm (0.75 in). The toads display yellow skin coloration with brownish They have webbed toes on their hind legs, but lack expanded toe tips. They lack external ears, but do possess normal anuran inner ear features, with

124-556: A cave environment limits an organism's ability to disperse, since caves are often not connected to each other. One hypothesis for how closely related troglobite species could become isolated from one another in different caves is that their common ancestor may have been less restricted to cave habitats. When climate conditions became unfavorable, the ancestral species was extirpated from the surface, but some populations survived in caves, and diverged into different species due to lack of gene flow between them. Isolated islands commonly develop

186-622: A combination of many. One of the major challenges the firm faced was revenue collection. With thousands of customers defaulting on their electricity payments, Tanesco planned to establish a convenient prepaid metering system for low demand users. Tanesco undertook a prepayment metering project between 1993 and 1997 though world bank funding. The new program was referred to as "Lipa Umeme Kadiri Utumiavyo"(LUKU) meaning "Pay for electricity as you need it" in English. The system allows users to recharge their units from multiple vendors in their communities plus

248-478: A euendemic the vicariance was geologic in nature, such as the movement of tectonic plates, but in a cryptoendemic the disjunct distribution was due to the extinction of the intervening populations. There is yet another possible situation that can cause a disjunct distribution, where a species is able to colonize new territories by crossing over areas of unsuitable habitat, such as plants colonizing an island – this situation they dismiss as extremely rare and do not devise

310-624: A high again in June 2003 (around 20,989 individuals), before steeply declining to a point in January 2004 when only three individuals could be seen and two males were heard calling. The species was listed as Extinct in the Wild in May 2009. The extinction in the wild of the Kihansi spray toad was mainly due to habitat loss following the construction of Kihansi Dam in 1999, which reduced the amount of water coming down from

372-402: A holoendemic is a cosmopolitan species. Stenoendemics, also known as local endemics, have a reduced distribution and are synonymous with the word 'endemics' in the traditional sense, whereas euryendemics have a larger distribution -both these have distributions that are more or less continuous. A rhoendemic has a disjunct distribution . Where this disjunct distribution is caused by vicariance, in

434-437: A limited range. Paleoendemism is more or less synonymous with the concept of a ' relict species ': a population or taxon of organisms that were more widespread or more diverse in the past. A 'relictual population' is a population that currently occurs in a restricted area, but whose original range was far wider during a previous geologic epoch . Similarly, a 'relictual taxon' is a taxon (e.g. species or other lineage) that

496-513: A much larger area, but died out in most of their range, are called paleoendemic , in contrast to neoendemic species, which are new species that have not dispersed beyond their range. The ginkgo tree, Ginkgo biloba , is one example of a paleoendemic species. In many cases biological factors, such as low rates of dispersal or returning to the spawning area ( philopatry ), can cause a particular group of organisms to have high speciation rates and thus many endemic species. For example, cichlids in

558-522: A name for. Traditionally, none of Myers and de Grave's categories would be considered endemics except stenoendemics. Some environments are particularly conducive to the development of endemic species, either because they allow the persistence of relict taxa that were extirpated elsewhere, or because they provide mechanisms for isolation and opportunities to fill new niches. Serpentine soils act as ' edaphic islands' of low fertility and these soils lead to high rates of endemism. These soils are found in

620-461: A number of endemics. Many species and other higher taxonomic groups exist in very small terrestrial or aquatic islands, which restrict their distribution. The Devil's Hole pupfish, Cyprinodon diabolis , has its whole native population restricted to a spring that is 20 x 3 meters, in Nevada 's Mojave Desert . This 'aquatic island' is connected to an underground basin; however, the population present in

682-512: A small exhibit for them. Groups numbering in the hundreds are now also maintained at Detroit Zoo and Omaha's Henry Doorly Zoo . In August 2010, a group of 100 Kihansi spray toads were flown from the Bronx Zoo and Toledo Zoo to their native Tanzania, as part of an effort to reintroduce the species into the wild, using a propagation center at the University of Dar es Salaam . In 2012, scientists from

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744-405: A species that is endemic is "precinctive", which applies to species (and other taxonomic levels) that are restricted to a defined geographical area. Other terms that sometimes are used interchangeably, but less often, include autochthonal, autochthonic, and indigenous; however, these terms do not reflect the status of a species that specifically belongs only to a determined place. The word endemic

806-500: A very restrictive range, due to the unique environmental characteristics. The Kula Volcano , one of the fourteen volcanoes in Turkey , is home to 13 endemic species of plants. Endemics might more easily become endangered or extinct because they are already restricted in distribution. This puts endemic plants and animals at greater risk than widespread species during the rapid climate change of this century. Some scientists claim that

868-625: A wide variety of evolutionary histories, so researchers often use more specialized terms that categorize endemic species based upon how they came to be endemic to an area. Different categorizations of endemism also capture the uniqueness and irreplaceability of biodiversity hotspots differently and impact how those hotspots are defined, affecting how resources for conservation are allocated. The first subcategories were first introduced by Claude P. E. Favager and Juliette Contandriopoulis in 1961: schizoendemics, apoendemics and patroendemics. Using this work, Ledyard Stebbins and Jack Major then introduced

930-437: A wider distributed taxon that has become reproductively isolated without becoming (potentially) genetically isolated – a schizoendemic has the same chromosome count as the parent taxon it evolved from. An apoendemic is a polyploid of the parent taxon (or taxa in the case of allopolyploids ), whereas a patroendemic has a lower, diploid chromosome count than the related, more widely distributed polyploid taxon. Mikio Ono coined

992-697: A workforce of 7,300 persons. Its main offices are located in Ubungo west of Dar es Salaam central business district and it operates regional offices throughout Tanzania . Electricity was first introduced in Tanzania ( Tanganyika ) in 1908 by the German colonial authorities in Dar-es-salaam . After the British mandate was established a Government electricity department was formed and took over energy generation and transmission in

1054-463: Is a Tanzanian parastatal organisation established in 1964. It is wholly owned by the government of Tanzania . The Ministry of Energy and Minerals regulates the operations of TANESCO . Its business include: electricity generation , electricity transmission , electricity distribution and sale of electricity to the Tanzanian mainland and bulk power supply to the island of Zanzibar . The company has

1116-457: Is also of interest in evolutionary biology , because it provides clues about how changes in the environment cause species to undergo range shifts (potentially expanding their range into a larger area, or becoming extirpated from an area they once lived), go extinct, or diversify into more species. The extreme opposite of an endemic species is one with a cosmopolitan distribution , having a global or widespread range. A rare alternative term for

1178-487: Is endemic to Earth. However, endemism is normally used only when a species has a relatively small or restricted range. This usage of "endemic" contrasts with "cosmopolitan." Endemics are not necessarily rare; some might be common where they occur. Likewise, not all rare species are endemics; some may have a large range but be rare throughout this range. The evolutionary history of a species can lead to endemism in multiple ways. Allopatric speciation , or geographic speciation,

1240-414: Is from Neo-Latin endēmicus , from Greek ἔνδημος, éndēmos , "native". Endēmos is formed of en meaning "in", and dēmos meaning "the people". The word entered the English language as a loan word from French endémique , and originally seems to have been used in the sense of diseases that occur at a constant amount in a country, as opposed to epidemic diseases, which are exploding in cases. The word

1302-410: Is mainly extension of grid connected and mini-grid connected distribution network to the rural areas. Small power producers are allowed to sell their power directly to the consumer and sell the excess to Tanesco. However, the tariffs of sale have been decided by Tanesco to maintain public interest. Below is a table showing the possible tariff cases an SPP can engage in; an SPP can engage in one case or

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1364-434: Is only possible where 1.) the taxonomy of the species in question is not in dispute; 2.) the species distribution is accurately known; and 3.) the species have relatively small distributional ranges. In a 2000 article, Myers et al . used the standard of having more than 0.5% of the world's plant species being endemic to the region to designate 25 geographical areas of the world as biodiversity hotspots . In response to

1426-619: Is organised under the following business units: Generation, Transmission, Distribution and Customer Services, Investment, Finance, Information, Communication and Technology, Human Resources and the Legal Counsel. The Tanzania Electric Supply company ltd. is wholly owned by the Government of Tanzania. It is a public corporation governed by the Public Corporations Act, revised edition 2002. There has been much debate to either privatise

1488-406: Is the overview of Tanesco's operations As of March 2015 : Generation Capacity in the interconnected grid system: Transmission network: Distribution network: Tanesco has to import a small amount of its energy from Uganda and Zambia to supply the needs of the bordering regions that are not connected to the national grid. Currently Tanzania only exports electricity to Kenya near

1550-618: Is the sole surviving representative of a formerly diverse group. The concept of phylogenetic endemism has also been used to measure the relative uniqueness of the species endemic to an area. In measurements that incorporate phylogenetic endemism, branches of the evolutionary tree are weighted by how narrowly they are distributed. This captures not only the total number of taxa endemic to the area (taxonomic endemism), but also how distant those species are from their living relatives. Schizoendemics, apoendemics and patroendemics can all be classified as types of neoendemics. Schizoendemics arise from

1612-710: Is when two populations of a species become geographically separated from each other and as a result develop into different species. In isolated areas where there is little possibility for organisms to disperse to new places, or to receive new gene flow from outside, the rate of endemism is particularly high. For example, many endemic species are found on remote islands , such as Hawaii , the Galápagos Islands and Socotra . Populations on an island are isolated, with little opportunity to interbreed with outside populations, which eventually causes reproductive isolation and separation into different species. Darwin's finches in

1674-689: The Horo Horo region, and the Isinya–Singida High Voltage Power Line is under construction. With the recent expansion of the Gas Sector in Tanzania the company has major plans to increase exports to neighbouring countries. In 2009 the Government through Energy and Water Utilities Regulatory Authority (EWURA) approved Small Power Project framework. Since the Government didn't have Renewable energy policy in place nor did they have any major plans for energy generation through renewable fuels,

1736-935: The Balkan Peninsula, Turkey, Alps, Cuba, New Caledonia, South Africa, Zimbabwe, the North American Appalachians, and scattered distribution in California, Oregon, and Washington and elsewhere. For example, Mayer and Soltis considered the widespread subspecies Streptanthus glandulosus subsp. glandulosus which grows on normal soils, to be a paleoendemic, whereas closely related endemic forms of S. glandulosus occurring on serpentine soil patches are neoendemics which recently evolved from subsp. glandulosus . Obligate cave-dwelling species, known as troglobites, are often endemic to small areas, even to single individual caves, because cave habitats are by nature restricted, isolated, and fragmented. A high level of adaptation to

1798-561: The East African Rift Lakes have diversified into many more endemic species than the other fish families in the same lakes, possibly due to such factors. Plants that become endemic on isolated islands are often those which have a high rate of dispersal and are able to reach such islands by being dispersed by birds. While birds are less likely to be endemic to a region based on their ability to disperse via flight, there are over 2,500 species which are considered endemic, meaning that

1860-742: The Galápagos archipelago are examples of species endemic to islands. Similarly, isolated mountainous regions like the Ethiopian Highlands , or large bodies of water far from other lakes, like Lake Baikal , can also have high rates of endemism. Endemism can also be created in areas which act as refuges for species during times of climate change like ice ages . These changes may have caused species to become repeatedly restricted to regions with unusually stable climate conditions, leading to high concentrations of endemic species in areas resistant to climate fluctuations. Endemic species that used to exist in

1922-646: The Kihansi Dam. These spray systems functioned to mimic the fine water spray that had existed prior to the diversion of the Kihansi river, maintaining the microhabitat. The installation was initially successful in maintaining the spray-zone habitat, but after 18 months, marsh and stream-side plants retreated and a weedy species overran the area, changing the overall plant-species composition. The next steps in environmental management included ecological monitoring, mitigation, establishing rights of water authority and Tanesco to implement hydrological resources for conservation of

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1984-465: The Kihansi River waterfall. These wetlands were characterized by dense, grassy vegetation including Panicum grasses, Selaginella kraussiana clubmosses, and snail ferns ( Tectaria gemmifera ). Areas within the spray zones of the waterfall experienced near-constant temperatures and 100% humidity. Currently, an artificial gravity-fed sprinkler system is in place to mimic the original conditions of

2046-724: The Kihansi spray toad and spray wetlands habitat. An ex situ breeding program is maintained by North American zoos in the effort to reintroduce the species back into the wild. The program was initiated in 2001 by the Bronx Zoo when almost 500 Kihansi spray toads were taken from their native gorge and placed in six U.S. zoos as a possible hedge against extinction. Initially its unusual life style and reproduction mode caused problems in captivity, and only Bronx Zoo and Toledo Zoo were able to maintain populations. By December 2004, fewer than 70 remained in captivity, but when their exact requirements were discovered greater survival and breeding success

2108-537: The above, the World Wildlife Fund has split the world into a few hundred geographical ' ecoregions '. These have been designed to include as many species as possible that only occur in a single ecoregion, and these species are thus 'endemics' to these ecoregions. Since plenty of these ecoregions have a high prevalence of endemics existing within them, many National Parks have been formed around or within them to further promote conservation. The Caparaó National Park

2170-420: The center returned a test population of 48 toads to the Kihansi gorge, having found means to co-inhabit the toads with substrates presumed to contain chytrid fungus. The substrates were extracted from the Kihansi gorge spray wetlands, and mixed with captive toads with their surrogate species from the wild. Reintroduction commenced because its substrate appeared to not harbor any infectious agents that could threaten

2232-587: The colony. In 1931 electricity was handed to two private companies, Tanganyika Electric Supply Company Ltd. (Tanesco) and Dar es Salaam and District Electric Supply Company Ltd (Danesco). Commercial operations for Tanesco began in 1933 with the first diesel generator in the Tanga Region . The first dam was completed in 1936 on the Pangani River . By 1959 the total capacity was 17.5MW and the company had 400 km of supply lines. On 12 February 1948 Tanesco secured

2294-725: The company or list the company on the Dar-es-salaam Stock Exchange . The government however encourages the public sector to enter the market and compete with Tanesco, however, the government is adamant to maintain its public status to help keep the cost of electricity always low for the majority of the population. The key trends for TANESCO's consolidated Group over recent years are shown below (as at year ending 30 June): Grid & Off-Grid Installed Capacity – 2012 by Fuel Type TANESCO's core business are: to generate, transmit, distribute and supply electricity in Tanzanian mainland and sell bulk power to Zanzibar . The following

2356-663: The concept by using WWF ecoregions and reptiles, finding that most reptile endemics occur in WWF ecoregions with high biodiversity. Other conservation efforts for endemics include keeping captive and semi-captive populations in zoological parks and botanical gardens. These methods are ex situ ("off-site") conservation methods. The use of such methods may not only offer refuge and protection for individuals of declining or vulnerable populations, but it may also allow biologists valuable opportunities to research them as well. TANESCO The Tanzania Electric Supply Company Limited (TANESCO)

2418-583: The concept. In their view, everything is endemic, even cosmopolitan species are endemic to Earth, and earlier definitions restricting endemics to specific locations are wrong. Thus the subdivisions neoendemics and paleoendemics are without merit regarding the study of distributions, because these concepts consider that an endemic has a distribution limited to one place. Instead, they propose four different categories: holoendemics, euryendemics, stenoendemics and rhoendemics. In their scheme cryptoendemics and euendemics are further subdivisions of rhoendemics. In their view,

2480-518: The concepts of neoendemics and paleoendemics in 1965 to describe the endemics of California. Endemic taxa can also be classified into autochthonous, allochthonous, taxonomic relicts and biogeographic relicts. Paleoendemism refers to species that were formerly widespread but are now restricted to a smaller area. Neoendemism refers to species that have recently arisen, such as through divergence and reproductive isolation or through hybridization and polyploidy in plants, and have not dispersed beyond

2542-551: The contract to sell surplus power from the hydro dam to Mombasa , Kenya. At independence (1961) the government acquired some shares from both of the utilities. However, with Tanzania's economic policy shifting towards Ujamaa , by 1975 the government acquired all the shares and merged the two utilities to form a state own utility called the Tanzania Electric Supply Company Ltd. From 1975 the firm responsible for generating, transmitting and distributing power on

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2604-587: The cool climates of mountain peaks are geographically isolated. For example, in the Alpes-Maritimes department of France, Saxifraga florulenta is an endemic plant that may have evolved in the Late Miocene and could have once been widespread across the Mediterranean Basin . Volcanoes also tend to harbor a number of endemic species. Plants on volcanoes tend to fill a specialized ecological niche , with

2666-476: The exception of tympanic membranes and air-filled middle ear cavities. Females are often duller in coloration, and males normally have more significant markings Additionally, males exhibit dark inguinal patches on their sides where their hind legs meet their abdomens. Abdominal skin is translucent, and developing offspring can often be seen in the bellies of gravid females. The toad breeds by using internal fertilization, in which females retain larvae internally in

2728-491: The government encouraged Renewable energy projects (mini hydro, biomass, solar and wind) with capacity range between 0.1 MW to 10 MW to be developed. Since introduction of SPPs only mini hydro and biomass power projects are in operation; the high cost of setup, fluctuating foreign exchange prices and low tariffs have discouraged investment. The SPP framework also ties in with The Rural Energy Agency (REA) and they are responsible for financing of rural electrification projects. This

2790-552: The mainland. Furthermore, Tanesco is also responsible in selling bulk electricity to Zanzibar based ZECO Electric Company. The government liberalised private sector investment in electricity generation in 1992. In 2002 as part of the Companies Act, 2002 of Tanzania, Tanesco was incorporated as a limited liability company; however all its shares were still held by the government. Due to the high dependence on Hydroelectric dams and poor hydrology between 2005 and 2008, Tanesco lead to

2852-593: The oviduct until their offspring are born. Prior to its extirpation, the Kihansi spray toad was endemic only to a two-hectare (5-acre) area at the base of the Kihansi River waterfall in the Udzungwa escarpment of the Eastern Arc Mountains in Tanzania . The Kihansi Gorge is about 4 km (2.5 mi) long with a north–south orientation. A number of wetlands made up the habitat of this species, all fed by spray from

2914-656: The pool remains isolated. Other areas very similar to the Galapagos Islands of the Pacific Ocean exist and foster high rates of endemism. The Socotra Archipelago of Yemen, located in the Indian Ocean, has seen a new endemic species of parasitic leech, Myxobdella socotrensis, appear. This species is restricted to freshwater springs, where it may attach to and feed upon native crabs. Mountains can be seen as ' sky islands ': refugia of endemics because species that live in

2976-404: The presence of endemic species in an area is a good method to find geographical regions that can be considered priorities for conservation. Endemism can thus be studied as a proxy for measuring biodiversity of a region. The concept of finding endemic species that occur in the same region to designate 'endemism hotspots' was first proposed by Paul Müller in a 1973 book. According to him, this

3038-527: The procurement of their first Emergency Power Project (EPP). The first EPP was the expansion of the Ubungo Power Station with Songas. From 2011 to 2013 TANESCO experienced a shortage of power generation due to poor hydrology and again procurement of costly EPPs was then undertaken. By the end of 2016, TANESCO sought an increase by 8.53 percent of the energy tariff, due to its difficult financial situation. In 2017, The president John Magufuli , dismissed

3100-460: The raise firing the director manager of TANESCO Felchesmi Mramba. Tanesco's management operations is conducted at their headquarters Umeme Park and is located in Ubungo , Dar es salaam . The Management of the company is under the managing director. Currently the managing director is Eng. Boniface Gissima Nyamo-Hanga appointed by the president Samia Suluhu Hassan in September 2023. The company

3162-435: The species in the wild might take time because it needs to adapt slowly to the wild habitat in which it needs to search for food, evade predators, and overcome disease, in contrast to the controlled environment they lived in during captivity. Endemic Endemism is an important concept in conservation biology for measuring biodiversity in a particular place and evaluating the risk of extinction for species. Endemism

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3224-480: The species is restricted to an area less than five million hectares (twelve million acres). Microorganisms were traditionally not believed to form endemics. The hypothesis 'everything is everywhere', first stated in Dutch by Lourens G.M. Baas Becking in 1934, describes the theory that the distribution of organisms smaller than 2 mm is cosmopolitan where habitats occur that support their growth. Endemism can reflect

3286-555: The spray zones. The species' global range covered an area of less than two hectares around the Kihansi Falls, and no additional populations have been located after searching for it around other waterfalls on the escarpment of the Udzungwa Mountains. Prior to extinction, there was a population of around 17,000 individuals and fluctuating naturally. The population hit a high in May 1999, dropped to lower numbers in 2001 and 2002, hit

3348-463: The survival of the species. In 2017 a reintroduction program will be launched and currently a few Kihansi spray toads will be successfully reintroduced in Tanzania. Despite strict protocols in the breeding facilities, toads are occasionally attacked by chytrid fungus, resulting in mass deaths at the Kihansi facility. Air conditioning and water filtration system malfunctions have also contributed to toad mortality. Researchers suggest that reintroduction of

3410-424: The term 'aneuendemics' in 1991 for species that have more or fewer chromosomes than their relatives due to aneuploidy . Pseudoendemics are taxa that have possibly recently evolved from a mutation. Holoendemics is a concept introduced by Richardson in 1978 to describe taxa that have remained endemic to a restricted distribution for a very long time. In a 2000 paper, Myers and de Grave further attempted to redefine

3472-565: The threatened nature of a geographic region. A similar pattern had been found regarding mammals, Lasioglossum bees, Plusiinae moths, and swallowtail butterflies in North America: these different groups of taxa did not correlate geographically with each other regarding endemism and species richness. Especially using mammals as flagship species proved to be a poor system of identifying and protecting areas of high invertebrate biodiversity. In response to this, other scientists again defended

3534-425: The waterfall into the gorge by 90 percent, hugely reducing the volume of the spray, particularly in the dry season, as well as altering vegetational composition. This led to the spray toad's microhabitat being compromised, as it reduced the amount of water spray, which the toads were reliant on. The sprinkler system that mimicked the natural water spray was not yet operational when the Kihansi Dam opened. In 2003 there

3596-527: Was a final population crash in the species. This coincided with a breakdown of the sprinkler system during the dry season, the appearance of the disease chytridiomycosis , and the brief opening of the Kihansi Dam to flush out sediments, which contained pesticides used in maize farming operations upstream. The last confirmed record of wild Kihansi spray toads was in 2004. Between July 2000 and March 2001, gravity-fed artificial spray systems were built and placed in three areas of spray wetlands that were affected by

3658-585: Was achieved. In November 2005, the Toledo Zoo opened an exhibit for the Kihansi spray toad, and for some time this was the only place in the world where it was on display to the public. The Toledo Zoo now has several thousand Kihansi spray toads, the majority off-exhibit. The Bronx Zoo also has several thousand Kihansi spray toads, and it opened a small exhibit for some of these in February 2010. In 2010 Toledo Zoo transferred 350 toads to Chattanooga Zoo , which has created

3720-509: Was first used in botany by Vaughan MacCaughey in Hawaii in 1917. A species is considered to be endemic to the area where it is found naturally, to the exclusion of other areas; presence in captivity or botanical gardens does not disqualify a species from being endemic. In theory, the term "endemic" could be applied on any scale; for example, the cougar is endemic to the Americas, and all known life

3782-555: Was formed in the Atlantic Forest , a biodiversity hotspot located in Brazil, in order to help protect valuable and vulnerable species. Other scientists have argued that endemism is not an appropriate measure of biodiversity, because the levels of threat or biodiversity are not actually correlated to areas of high endemism. When using bird species as an example, it was found that only 2.5% of biodiversity hotspots correlate with endemism and

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3844-464: Was used in biology in 1872 to mean a species restricted to a specific location by Charles Darwin . The less common term 'precinctive' has been used by some entomologists as the equivalent of 'endemic'. Precinctive was coined in 1900 by David Sharp when describing the Hawaiian insects, as he was uncomfortable with the fact that the word ' endemic ' is often associated with diseases. 'Precinctive'

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