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Roccella Albida
''Roccella albida'' is a species of saxicolous (rock-dwelling), fruticose lichen in the family Roccellaceae. It is found on the Galápagos Islands. The lichen is characterised by its distinctively shaped, cylindrical or slightly depressed branches that vary in length from 5 to 20 cm and are white to white-greyish in colour, with infrequent soredia. The lichen has a cottony medulla, commonly white or sometimes pale yellowish-brown, and has frequent ascomata (fruiting bodies) with wavy margins. Taxonomy The lichen was formally described as a new species in 2009 by the mycologist Anders Tehler. The species epithet ''albida'' is derived from its whitish thallus, distinguishing it from the more brownish-grey thalli of its closely related species such as '' Roccella galapagoensis'', '' R. margaritifera'', and '' R. nigerrima''. Description ''Roccella albida'' has a distinctively shaped thallus, which forms branches that are (cylindrical and smooth) or slightly (mark ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saxicolous Lichen
A saxicolous lichen is a lichen that grows on rock. The prefix "sax" from the Latin means "rock" or "stone". Characteristics Saxicolous lichens exhibit very slow growth rates. They may develop on rock substrates for long periods of time, given the absence of external disturbances. The importance of the mineral composition of the rock substrate, as well as the elemental geochemistry Geochemistry is the science that uses the tools and principles of chemistry to explain the mechanisms behind major geological systems such as the Earth's crust and its oceans. The realm of geochemistry extends beyond the Earth, encompassing the ... is also important to the distribution of saxicolous lichens, but the relationship between the substrate influence on lichens, either chemical or textural, is still obscure. Communities of saxicolous lichens are often species-rich in terms of number. References Lichenology {{lichen-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secondary Metabolite
Secondary metabolites, also called specialised metabolites, toxins, secondary products, or natural products, are organic compounds produced by any lifeform, e.g. bacteria, fungi, animals, or plants, which are not directly involved in the normal growth, development, or reproduction of the organism. Instead, they generally mediate ecological interactions, which may produce a selective advantage for the organism by increasing its survivability or fecundity. Specific secondary metabolites are often restricted to a narrow set of species within a phylogenetic group. Secondary metabolites often play an important role in plant defense against herbivory and other interspecies defenses. Humans use secondary metabolites as medicines, flavourings, pigments, and recreational drugs. The term secondary metabolite was first coined by Albrecht Kossel, a 1910 Nobel Prize laureate for medicine and physiology in 1910. 30 years later a Polish botanist Friedrich Czapek described secondary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Española Island
Española Island ( Spanish: ''Isla Española'') is part of the Galápagos Islands. The English named it ''Hood Island'' after Viscount Samuel Hood. It is located in the extreme southeast of the archipelago and is considered, along with Santa Fe, one of the oldest, at approximately four million years. A popular tourist stop, Isla Española is the most southerly island in the Galápagos Archipelago. The climate is very dry, like most of the Archipelago. But due to the flatness of the island, it is the driest of these islands, with only a few inches of rain per year. It is about a 10- to 12-hour trip by boat from Isla Santa Cruz. Wildlife Tourists come to see the waved albatrosses (from March to January, almost the entire world population breeds on the island) and the mating dances of blue-footed boobies. Two spots are especially popular with visitors: Bahía Gardner, which has a lovely beach; and Punta Suárez, of interest because of its varied bird-life. This island has it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Santa Cruz Island
Santa Cruz Island ( Spanish: ''Isla Santa Cruz'', Chumash: ''Limuw'') is located off the southwestern coast of Ventura, California, United States. It is the largest island in California and largest of the eight islands in the Channel Islands archipelago and Channel Islands National Park. Forming part of the northern group of the Channel Islands, Santa Cruz is long and wide with an area of . The island's coastline has steep cliffs, large sea caves, coves, and sandy beaches. The highest point is Devils Peak, at over . A central valley splits the island along the Santa Cruz Island Fault, with volcanic rock on the north and older sedimentary rock on the south. This volcanic rock was heavily fractured during an uplift phase that formed the island, and over a hundred large sea caves have been carved into the resulting faults. The largest of these is Painted Cave, among the world's largest. The island is part of Santa Barbara County, California. The 2000 census showed a popul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
San Cristóbal Island
San Cristóbal Island ( es, Isla San Cristóbal) and named previously by the English as ''Chatham Island'', is the easternmost island in the Galápagos archipelago, as well as one of the oldest geologically. It is administratively part of San Cristóbal Canton, Ecuador. Its Spanish (and official Ecuadorian) name "San Cristóbal" comes from the patron saint of seafarers, St. Christopher. English speakers increasingly use that name in preference to the traditional English name of Chatham Island, derived from William Pitt, 1st Earl of Chatham. History San Cristobal Island is composed of three or four fused volcanoes, all extinct. It is home to the oldest permanent settlement of the islands and is the island where Darwin first went ashore in 1835. A small lake called El Junco is the only source of fresh water in the islands. The availability of fresh water is what led to the early settlement of San Cristobal. A penal colony was built on San Cristóbal Island in 1880 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rábida Island
Rábida Island (), is one of the Galápagos Islands. The island has also been known as Jervis Island named in honour of the 18th-century British admiral John Jervis. In Ecuador it is officially known as Isla Rábida. Wildlife In addition to flamingos and the bachelor sea lion colony, pelicans, white-cheeked pintails, boobies, and nine species of finch have been reported. The rich wildlife attracts a number of tourists cruises. In 1971 the Galápagos National Park Service successfully eradicated goats from Rábida. This introduced species upset the natural environment and led to the extinction of several native creatures including geckos, land iguanas, and rice rats. Conservation and Restoration During January 2011, invasive rodents were removed from the island by The Galápagos National Park, assisted by Island Conservation to benefit Galapagos penguins and ''Scalesia stewartii'' (a tree forming daisy and the plant equivalent of one of Darwin's finches Darwin's finch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pinzón Island
Pinzón Island (Spanish: ''Isla Pinzón''), sometimes called Duncan Island (after Adam Duncan, 1st Viscount Duncan), is an island in the Galápagos Islands, Ecuador. Pinzón is home to giant Galápagos tortoises of the endemic subspecies '' Chelonoidis duncanensis'', Galápagos sea lions and other endemic species. It has no visitor facilities and a permit is required to visit. It has an area of 18 km2 and a maximum altitude of 458 meters. Pinzón marks the geographical center of the Galápagos Islands, but neither of the two main Galápagos tree species are present. A unique species of daisy tree is found in the humid zone. Restoration During January 2012, invasive rodents were removed from the island by The Galápagos National Park, assisted by Island Conservation to benefit the Pinzón giant tortoise. An infestation of non-native rat Rats are various medium-sized, long-tailed rodents. Species of rats are found throughout the order Rodentia, but stereotypical ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Floreana Island
Floreana Island (Spanish: ''Isla Floreana'') is an island of the Galápagos Islands. It was named after Juan José Flores, the first president of Ecuador, during whose administration the government of Ecuador took possession of the archipelago. It was previously called Charles Island (after King Charles II of England), and Santa María after one of the caravels of Columbus. The island has an area of . It was formed by volcanic eruption. The island's highest point is Cerro Pajas at , which is also the highest point of the volcano like most of the smaller islands of Galápagos. History Since the 19th century, whalers kept a wooden barrel at Post Office Bay, so that mail could be picked up and delivered to their destination by ships on their way home, mainly to Europe and the United States. Cards and letters are still placed in the barrel without any postage. Visitors sift through the letters and cards in order to deliver them by hand. Due to its relatively flat surface, su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Santa Fe Island
Santa Fe Island (Spanish: ''Isla Santa Fe''), also called Barrington Island after admiral Samuel Barrington, is a small island of which lies in the centre of the Galápagos archipelago, to the south-east of Santa Cruz Island. Visitor access is by a wet landing in Barrington Bay on the north-eastern side of the island. Environment Geologically, the island is one of the oldest of the archipelago; volcanic rocks of about 4 million years old have been found. The vegetation of the island is characterized by brush, palo santo trees and stands of a large subvariety of the Galápagos prickly pear cactus, ''Opuntia galapageia'' subvar. ''barringtonensis''. Santa Fe is home to two endemic species and two endemic subspecies: the Barrington land iguana (''Conolophus pallidus''), the Barrington leaf-toed gecko (''Phyllodactylus barringtonensis''), www.reptile-database.org. the Santa Fe marine iguana (''Amblyrhynchus cristatus trillmichi'') and the Santa Fe rice rat (''Aegialomys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endemism
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, the Cape sugarbird is found exclusively in southwestern South Africa and is therefore said to be ''endemic'' to that particular part of the world. An endemic species can be also be referred to as an ''endemism'' or in scientific literature as an ''endemite''. For example ''Cytisus aeolicus'' is an endemite of the Italian flora. ''Adzharia renschi'' was once believed to be an endemite of the Caucasus, but it was later discovered to be a non-indigenous species from South America belonging to a different genus. The extreme opposite of an endemic species is one with a cosmopolitan distribution, having a global or widespread range. A rare alternative term for a species that is endemic is "precinctive", which applies t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High-performance Thin-layer Chromatography
High-performance thin-layer chromatography (HPTLC) is an enhanced form of thin-layer chromatography (TLC). A number of enhancements can be made to the basic method of thin-layer chromatography to automate the different steps, to increase the resolution achieved, and to allow more accurate quantitative measurements. Automation is useful to overcome the uncertainty in droplet size and position when the sample is applied to the TLC plate by hand. One approach to automation has been the use of piezoelectric devices and inkjet printers for applying the sample. The spot capacity (analogous to peak capacity in HPLC) can be increased by developing the plate with two different solvents, using two-dimensional chromatography Two-dimensional chromatography is a type of chromatographic technique in which the injected sample is separated by passing through two different separation stages. Two different chromatographic columns are connected in sequence, and the effluent fr .... The procedu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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