|
Varanus Ornatus
The ornate monitor (''Varanus niloticus ornatus'') is a monitor lizard that is native to West and Middle Africa. Comprehensive molecular analyses of the group have demonstrated that animals previously assigned to "''Varanus ornatus''" do not constitute a valid taxon and are actually polymorphisms of two different species; ''Varanus stellatus'' (west African Nile monitor) and ''Varanus niloticus'' (Nile monitor).Dowell, S.A, D.M. Portik, V. de Buffrenil, I. Ineich, E. Greenbaum, S.O. Kolokotronis and E.R. Hekkala. (2015). Molecular data from contemporary and historical collections reveal a complex story of cryptic diversification in the ''Varanus (Polydaedalus) niloticus'' Species Group. ''Molecular Phylogenetics and Evolution.'' doi:10.1016/j.ympev.2015.10.004 Consequently, ''Varanus ornatus'' is considered a synonym of ''Varanus niloticus'' and "ornate monitor" is an informal term for forest forms of either species (''V. niloticus'' or ''V. stellatus''). Until 1997, the ornate m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
François Marie Daudin
François Marie Daudin (; 29 August 1776 in Paris – 30 November 1803 in Paris) was a French zoologist. With legs paralyzed by childhood disease, he studied physics and natural history, but ended up being devoted to the latter. Daudin wrote ' (Complete and Elementary Treatise of Ornithology) in 1799–1800. It was one of the first modern handbooks of ornithology, combining Linnean binomial nomenclature with the anatomical and physiological descriptions of Buffon. While an excellent beginning, it was never completed. In 1800, he also published ''Recueil de mémoires et de notes sur des espèces inédites ou peu connues de mollusques, de vers et de zoophytes'' (Collection of memories and notes on new or little-known species of molluscs, worms and zoophytes). Daudin found his greatest success in herpetology. He published ''Histoire naturelle des reinettes, des grenouilles et des crapauds'' (Natural history of tree frogs, frogs and toads) in 1802, and ''Histoire naturelle, gé ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hatchling Varanus Ornatus
In oviparous biology, a hatchling is a newly hatched fish, amphibian, reptile, or bird. A group of mammals called monotremes lay eggs, and their young are hatchlings as well. Fish Fish hatchlings generally do not receive parental care, similar to reptiles. Like reptiles, fish hatchlings can be affected by xenobiotic compounds. For example, exposure to xenoestrogens can feminize fish. As well, hatchlings raised in water with high levels of carbon dioxide demonstrate unusual behaviour, such as being attracted to the scent of predators. This change could be reversed by immersion into gabazine water, leading to the hypothesis that acidic waters affect hatchling brain chemistry. Amphibians The behavior of an amphibian hatchling, commonly referred to as a tadpole, is controlled by a few thousand neurons. 99% of a ''Xenopus'' hatchling's first day after hatching is spent hanging from a thread of mucus secreted from near its mouth will eventually form; if it becomes detached from this t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monitor Lizard
Monitor lizards are lizards in the genus ''Varanus,'' the only extant genus in the family Varanidae. They are native to Africa, Asia, and Oceania, and one species is also found in the Americas as an invasive species. About 80 species are recognized. Monitor lizards have long necks, powerful tails and claws, and well-developed limbs. The adult length of extant species ranges from in some species, to over in the case of the Komodo dragon, though the extinct varanid known as megalania (''Varanus priscus'') may have been capable of reaching lengths more than . Most monitor species are terrestrial, but arboreal and semiaquatic monitors are also known. While most monitor lizards are carnivorous, eating eggs, smaller reptiles, fish, birds, insects, and small mammals, some also eat fruit and vegetation, depending on where they live. Distribution The various species cover a vast area, occurring through Africa, the Indian subcontinent, to China, the Ryukyu Islands in southern Japan, s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
West Africa
West Africa or Western Africa is the westernmost region of Africa. The United Nations defines Western Africa as the 16 countries of Benin, Burkina Faso, Cape Verde, The Gambia, Ghana, Guinea, Guinea-Bissau, Ivory Coast, Liberia, Mali, Mauritania, Niger, Nigeria, Senegal, Sierra Leone, and Togo, as well as Saint Helena, Ascension and Tristan da Cunha ( United Kingdom Overseas Territory).Paul R. Masson, Catherine Anne Pattillo, "Monetary union in West Africa (ECOWAS): is it desirable and how could it be achieved?" (Introduction). International Monetary Fund, 2001. The population of West Africa is estimated at about million people as of , and at 381,981,000 as of 2017, of which 189,672,000 are female and 192,309,000 male. The region is demographically and economically one of the fastest growing on the African continent. Early history in West Africa included a number of prominent regional powers that dominated different parts of both the coastal and internal trade networks, suc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middle Africa
Central Africa is a subregion of the African continent comprising various countries according to different definitions. Angola, Burundi, the Central African Republic, Chad, the Democratic Republic of the Congo, the Republic of the Congo, Equatorial Guinea, Gabon, Rwanda, and São Tomé and Príncipe are members of the Economic Community of Central African States (ECCAS). Six of those states (the Central African Republic, Chad, the Republic of the Congo, Equatorial Guinea, and Gabon) are also members of the Economic and Monetary Community of Central Africa (CEMAC) and share a common currency, the Central African CFA franc. The African Development Bank defines Central Africa as the Central African Republic, Chad, the Democratic Republic of the Congo, the Republic of the Congo, Equatorial Guinea, and Gabon. Middle Africa is an analogous term used by the United Nations in its geoscheme for Africa. It includes the same countries as the African Development Bank's definition, al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taxon
In biology, a taxon (back-formation from ''taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and given a particular ranking, especially if and when it is accepted or becomes established. It is very common, however, for taxonomists to remain at odds over what belongs to a taxon and the criteria used for inclusion. If a taxon is given a formal scientific name, its use is then governed by one of the nomenclature codes specifying which scientific name is correct for a particular grouping. Initial attempts at classifying and ordering organisms (plants and animals) were set forth in Carl Linnaeus's Linnaean taxonomy, system in ''Systema Naturae'', 10th edition (1758), as well as an unpublished work by Bernard de Jussieu, Bernard and Antoine Laurent de Jussieu. The idea of a unit-based system of biological classification was first mad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymorphism (biology)
In biology, polymorphism is the occurrence of two or more clearly different morphs or forms, also referred to as alternative ''phenotypes'', in the population of a species. To be classified as such, morphs must occupy the same habitat at the same time and belong to a panmictic population (one with random mating). Ford E.B. 1965. ''Genetic polymorphism''. Faber & Faber, London. Put simply, polymorphism is when there are two or more possibilities of a trait on a gene. For example, there is more than one possible trait in terms of a jaguar's skin colouring; they can be light morph or dark morph. Due to having more than one possible variation for this gene, it is termed 'polymorphism'. However, if the jaguar has only one possible trait for that gene, it would be termed "monomorphic". For example, if there was only one possible skin colour that a jaguar could have, it would be termed monomorphic. The term polyphenism can be used to clarify that the different forms arise from the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Varanus Stellatus
The West African Nile monitor (''Varanus niloticus stellatus'') is a species of monitor lizard that is native to West African forests and adjacent savannah (east to northern Cameroon). It has also been introduced to Florida, United States, where it is considered invasive.Yong, Ed (20 April 2016)Florida’s Dragon Problem The Atlantic. Retrieved 15 September 2019. This cryptic species has traditionally been included in the Nile monitor (''V. niloticus''), but from 1997 to 2015 it was often considered as the western population of the ornate monitor (''V. ornatus''). Compared to the other members of the Nile monitor species complex (which also includes the ornate monitor of Central Africa), the West African Nile monitor has a genetic sequence divergence of more than 8%, meaning that they separated about 7.7 million years ago. This is a larger divergence than between humans and chimpanzees. Despite this, the Reptile Database continues to place it within the Nile monitor, bu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Varanus Niloticus
The Nile monitor (''Varanus niloticus'') is a large member of the monitor family (Varanidae) found throughout most of Sub-Saharan Africa and along the Nile, with invasive populations in North America. The population in West African forests and savannahs is sometimes recognized as a separate species, the West African Nile monitor (''V. stellatus'').Dowell, S.A, D.M. Portik, V. de Buffrenil, I Ineich, E Greenbaum, S.O. Kolokotronis and E.R. Hekkala. 2016. Molecular data from contemporary and historical collections reveal a complex story of cryptic diversification in the Varanus (Polydaedalus) niloticus Species Group. Molecular Phylogenetics and Evolution 94(Part B): 591-604. It is one of the largest lizards in the world reaching and even surpassing the perentie by size. Other common names include the African small-grain lizard, as well as iguana and various forms derived from it, such as guana, water leguaan or river leguaan (leguan, leguaan, and likkewaan mean monitor lizard in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subspecies
In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species have subspecies, but for those that do there must be at least two. Subspecies is abbreviated subsp. or ssp. and the singular and plural forms are the same ("the subspecies is" or "the subspecies are"). In zoology, under the International Code of Zoological Nomenclature, the subspecies is the only taxonomic rank below that of species that can receive a name. In botany and mycology, under the International Code of Nomenclature for algae, fungi, and plants, other infraspecific ranks, such as variety, may be named. In bacteriology and virology, under standard bacterial nomenclature and virus nomenclature, there are recommendations but not strict requirements for recognizing other important infraspecific ranks. A taxonomist decides whether ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ocelli
A simple eye (sometimes called a pigment pit) refers to a form of eye or an optical arrangement composed of a single lens and without an elaborate retina such as occurs in most vertebrates. In this sense "simple eye" is distinct from a multi-lensed "compound eye", and is not necessarily at all simple in the usual sense of the word. The structure of an animal's eye is determined by the environment in which it lives, and the behavioural tasks it must fulfill to survive. Arthropods differ widely in the habitats in which they live, as well as their visual requirements for finding food or conspecifics, and avoiding predators. Consequently, an enormous variety of eye types are found in arthropods. They possess a wide variety of novel solutions to overcome visual problems or limitations. Use of the term ''simple eye'' is flexible, and must be interpreted in proper context; for example, the eyes of humans and of other large animals such as most cephalopods, are ''camera eyes'' and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
