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Swordtail Fish
The green swordtail (''Xiphophorus hellerii'') is a species of freshwater/brackish fish in family Poeciliidae of order Cyprinodontiformes. A live-bearer, it is closely related to the southern platyfish or 'platy' (''X. maculatus'') and can crossbreed with it. It is native to an area of North and Central America stretching from Veracruz, Mexico, to northwestern Honduras. Description The male green swordtail grows to a maximum overall length of and the female to . The name 'swordtail' is derived from the elongated lower lobe of the male's caudal fin (tailfin). Sexual dimorphism is moderate, with the female being larger than the male, but lacking the 'sword'. The wild form is olive green in color, with a red or brown lateral stripe and speckles on the dorsal and, sometimes, caudal fins. The male's 'sword' is yellow, edged in black below. Captive breeding has produced many color varieties, including black, red, and many patterns thereof, for the aquarium hobby. All varieties ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Johann Jakob Heckel
Johann Jakob Heckel (23 January 1790 – 1 March 1857) was an Austrian taxidermist, zoology, zoologist, and ichthyology, ichthyologist from Mannheim in the Electoral Palatinate. He worked at the Royal natural history cabinet in Vienna which later became the Austrian Museum of Natural History. Life Heckel was born in Mannheim, the son of a namesake music teacher and Sophia née Reinhardt. He also had a namesake brother who studied music and was educated at home and lived in Vienna for a while. Another brother was Karl Ferdinand Heckel (1800-1870) who also studied music. In 1805 the family fled the French to Pressburg and then to Pest. Heckel visited the Georgicon agricultural college in 1806. His father bought a farm in Gumpoldskirchen and after the death of his father in December 1811, his mother took over the farm, assisted by his brother. He married Barbara Baumgartner in 1817 and in 1818 he was working at the Vienna Naturaliencabinet (which later became the Naturhistorisches Mu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sexual Dimorphism
Sexual dimorphism is the condition where sexes of the same species exhibit different Morphology (biology), morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecy, dioecious species, which consist of most animals and some plants. Differences may include secondary sex characteristics, size, weight, color, markings, or behavioral or cognitive traits. Male-male reproductive competition has evolved a diverse array of sexually dimorphic traits. Aggressive utility traits such as "battle" teeth and blunt heads reinforced as battering rams are used as weapons in aggressive interactions between rivals. Passive displays such as ornamental feathering or song-calling have also evolved mainly through sexual selection. These differences may be subtle or exaggerated and may be subjected to sexual selection and natural selection. The opposite of dimorphism is ''monomorphism'', when both biological sexes are phenotype, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Namibia
Namibia, officially the Republic of Namibia, is a country on the west coast of Southern Africa. Its borders include the Atlantic Ocean to the west, Angola and Zambia to the north, Botswana to the east and South Africa to the south; in the northeast, approximating a quadripoint, Zimbabwe lies less than 200 metres (660 feet) away along the Zambezi, Zambezi River near Kazungula, Zambia. Namibia's capital and largest city is Windhoek. Namibia is the driest country in sub-Saharan Africa, and has been inhabited since prehistoric times by the Khoekhoe, Khoi, San people, San, Damara people, Damara and Nama people. Around the 14th century, immigration, immigrating Bantu peoples arrived as part of the Bantu expansion. From 1600 the Ovambo people#History, Ovambo formed kingdoms, such as Ondonga and Oukwanyama. In 1884, the German Empire established rule over most of the territory, forming a colony known as German South West Africa. Between 1904 and 1908, German troops waged a punitive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Otjikoto Lake
Otjikoto Lake is the smaller of only two permanent natural lakes in Namibia. It is a sinkhole lake that was created by a collapsing karst cave. It is located north-west of Tsumeb and only 100 meters from the main road B1. The lake was declared a national monument in 1972. The diameter of the lake is ; its depth is supposedly more than 91.44 meters, according to scans. According to a Namibian tourism information organisation, "the depth varies from sixty two meters at the side to one hundred meters in the center - and in some places leading off from the side - depths of one hundred meters have been recorded", while an article in the Allgemeine Zeitung explains the depth problem: "the lake tapers into a lateral cave system making it impossible to determine its exact depth, estimated to be in access (''sic'') of 142 meters." The lake was known to the San under the name ''Gaisis'' ("ugly"). When the Herero moved into the area, they named it ''Otjikoto'' (Otjiherero: "deep hole"). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zimbabwe
file:Zimbabwe, relief map.jpg, upright=1.22, Zimbabwe, relief map Zimbabwe, officially the Republic of Zimbabwe, is a landlocked country in Southeast Africa, between the Zambezi and Limpopo Rivers, bordered by South Africa to the south, Botswana to the southwest, Zambia to the north, and Mozambique to the east. The capital and largest city is Harare, and the second largest is Bulawayo. A country of roughly 16.6 million people as per 2024 census, Zimbabwe's largest ethnic group are the Shona people, Shona, who make up 80% of the population, followed by the Northern Ndebele people, Northern Ndebele and other #Demographics, smaller minorities. Zimbabwe has 16 official languages, with English, Shona language, Shona, and Northern Ndebele language, Ndebele the most common. Zimbabwe is a member of the United Nations, the Southern African Development Community, the African Union, and the Common Market for Eastern and Southern Africa. The region was long inhabited by the San people, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chinhoyi Caves
The Chinhoyi Caves (previously the Sinoia Caves) are a group of limestone and dolomite caves in north central Zimbabwe. Designated a National Park in 1955, and managed by the Zimbabwe Parks & Wildlife Management Authority. Location The caves are located in Makonde District, Mashonaland West Province, in north central Zimbabwe. They lie approximately , by road, northwest of Chinhoyi (formerly Sinoia), the nearest large town, and the location of the district and provincial headquarters. This location lies about , northwest of Harare, the capital. The caves lie on the main road, Highway A-1, between Harare and Chirundu, at the International border with the Republic of Zambia, about , further northwest of the caves. Overview The cave system is composed of limestone and dolomite. The main cave contains a pool of cobalt blue water, which is popularly called ''Sleeping Pool'' or ''Chirorodziva'' ("Pool of the Fallen"). Divers have discovered a submarine passage leading from the ''Bat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South Africa
South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic Ocean, South Atlantic and Indian Ocean; to the north by the neighbouring countries of Namibia, Botswana, and Zimbabwe; to the east and northeast by Mozambique and Eswatini; and it encloses Lesotho. Covering an area of , the country has Demographics of South Africa, a population of over 64 million people. Pretoria is the administrative capital, while Cape Town, as the seat of Parliament of South Africa, Parliament, is the legislative capital, and Bloemfontein is regarded as the judicial capital. The largest, most populous city is Johannesburg, followed by Cape Town and Durban. Cradle of Humankind, Archaeological findings suggest that various hominid species existed in South Africa about 2.5 million years ago, and modern humans inhabited the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transvaal Province
The Province of Transvaal (), commonly referred to as the Transvaal (; ), was a province of South Africa from 1910 until 1994, when a new constitution subdivided it following the end of apartheid. The name "Transvaal" refers to the province's geographical location to the north of the Vaal River. Its capital was Pretoria, which was also the country's executive capital. History In 1910, four British colonies united to form the Union of South Africa. The Transvaal Colony, which had been formed out of the bulk of the old South African Republic after the Second Boer War, became the Transvaal Province in the new union. Half a century later, in 1961, the union ceased to be part of the Commonwealth of Nations and became the Republic of South Africa. The PWV (Pretoria- Witwatersrand- Vereeniging) conurbation in the Transvaal, centred on Pretoria and Johannesburg, became South Africa's economic powerhouse, a position it still holds today as Gauteng Province. In 1994, after the fall o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
KwaZulu-Natal Province
KwaZulu-Natal (, also referred to as KZN) is a Provinces of South Africa, province of South Africa that was created in 1994 when the government merged the Zulu people, Zulu bantustan of KwaZulu ("Place of the Zulu" in Zulu language, Zulu) and Natal Province. It is located in the southeast of the country, with a long shoreline on the Indian Ocean. It shares borders with three other provinces and the countries of Mozambique, Eswatini and Lesotho. Its capital is Pietermaritzburg, and its largest city is Durban, which is also the Port of Durban, city with the largest port in sub-saharan Africa. It is the second-most populous province in South Africa, after Gauteng. Two areas in KwaZulu-Natal have been declared UNESCO World Heritage Sites: the iSimangaliso Wetland Park and the uKhahlamba Drakensberg Park. These areas are important to the surrounding ecosystems. During the 1830s and early 1840s, the northern part of what is now KwaZulu-Natal was established as the Zulu Kingdom. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Africa
Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surface area.Sayre, April Pulley (1999), ''Africa'', Twenty-First Century Books. . With nearly billion people as of , it accounts for about of the world's human population. Demographics of Africa, Africa's population is the youngest among all the continents; the median age in 2012 was 19.7, when the worldwide median age was 30.4. Based on 2024 projections, Africa's population will exceed 3.8 billion people by 2100. Africa is the least wealthy inhabited continent per capita and second-least wealthy by total wealth, ahead of Oceania. Scholars have attributed this to different factors including Geography of Africa, geography, Climate of Africa, climate, corruption, Scramble for Africa, colonialism, the Cold War, and neocolonialism. Despite this lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Introduced Species
An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived there by human activity, directly or indirectly, and either deliberately or accidentally. Non-native species can have various effects on the local ecosystem. Introduced species that become established and spread beyond the place of introduction are considered naturalized. The process of human-caused introduction is distinguished from biological colonization, in which species spread to new areas through "natural" (non-human) means such as storms and rafting. The Latin expression neobiota captures the characteristic that these species are ''new'' biota to their environment in terms of established biological network (e.g. food web) relationships. Neobiota can further be divided into neozoa (also: neozoons, sing. neozoon, i.e. animals) and ne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annelid
The annelids (), also known as the segmented worms, are animals that comprise the phylum Annelida (; ). The phylum contains over 22,000 extant species, including ragworms, earthworms, and leeches. The species exist in and have adapted to various ecologies – some in marine environments as distinct as tidal zones and hydrothermal vents, others in fresh water, and yet others in moist terrestrial environments. The annelids are bilaterally symmetrical, triploblastic, coelomate, invertebrate organisms. They also have parapodia for locomotion. Most textbooks still use the traditional division into polychaetes (almost all marine), oligochaetes (which include earthworms) and leech-like species. Cladistic research since 1997 has radically changed this scheme, viewing leeches as a sub-group of oligochaetes and oligochaetes as a sub-group of polychaetes. In addition, the Pogonophora, Echiura and Sipuncula, previously regarded as separate phyla, are now regarded as sub-grou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
