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Xibalbanus Tulumensis
''Xibalbanus tulumensis'' (previously ''Speleonectes tulumensis'' – ''Speleonectes'' = 'cave swimmer'; ''tulumensis'' = 'occurring at Tulum' – ''Xibalbanus'' = 'from Xibalba') is a venomous, hermaphroditic crustacean found in anchialine caves on the Yucatán Peninsula in the Caribbean Sea. This blind remipede liquefies the body contents of other crustaceans with a venom similar to that of rattlesnakes, and which includes digestive enzymes and a paralysing toxin. In her 1987 description, Smithsonian biologist Jill Yager wrote 'Body elongate, slender, without eyes or pigment. Cephalic shield small, tapering slightly at anterior end. Trunk segment numbers increasing with age, maximum number examined was 36 segments'. The numerous legs are used as oars for swimming. The species is long, and found in cenotes close to the sea, with salty seawater lying beneath the fresh water, and grading smoothly from one type to the other ( halocline). Stygobites are organisms found in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Troglomorphism
Troglomorphism is the morphological adaptation of an animal to living in the constant darkness of caves, characterised by features such as loss of pigment, reduced eyesight or blindness, and frequently with attenuated bodies and/or appendages. The terms troglobitic, stygobitic, stygofauna, troglofauna, and hypogean or hypogeic, are often used for cave-dwelling organisms. A 2012 study by a team from the National University of Singapore found that reductive changes in freshwater cave crabs evolved at the same rate as constructive changes. This shows that both selection and evolution have a role in advancing reductive changes (e.g smaller eyes) and constructive changes (e.g larger claws), making troglomorphic adaptations subject to strong factors that affect an organism's morphology. Troglomorphism occurs in molluscs, velvet worms, arachnids, myriapods, crustaceans, insects, fish, amphibians (notably cave salamanders) and reptiles. To date no mammals or birds have been found to live ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Contributions To Zoology
''Contributions to Zoology'' (formerly known as ''Bijdragen tot de Dierkunde'') is a scientific journal that started in 1848 as a publication of the Committee in charge of the library of the Dutch Royal Zoological Society "Natura Artis Magistra" and became integrated in the library of the University of Amsterdam in 1939. Since 2019 the journal is published by Brill publishers, Leiden. The journal has been freely available online since 1997. The current editor-in-chief is Ronald Vonk from Naturalis Biodiversity Center, Leiden. Contributions to Zoology solicits high-quality papers in all systematics-related branches of comparative zoology (including paleozoology). Preference is given to manuscripts dealing with conceptual issues and to integrative papers (e.g., ecology and biodiversity, morphology and phylogeny and character state evolution, phylogeny and historical biogeography, systematics and bioinformatics, bioinformatics and biodiversity, habitat disturbance and biogeography ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nature (journal)
''Nature'' is a British weekly scientific journal founded and based in London, England. As a multidisciplinary publication, ''Nature'' features peer-reviewed research from a variety of academic disciplines, mainly in science and technology. It has core editorial offices across the United States, continental Europe, and Asia under the international scientific publishing company Springer Nature. ''Nature'' was one of the world's most cited scientific journals by the Science Edition of the 2019 '' Journal Citation Reports'' (with an ascribed impact factor of 42.778), making it one of the world's most-read and most prestigious academic journals. , it claimed an online readership of about three million unique readers per month. Founded in autumn 1869, ''Nature'' was first circulated by Norman Lockyer and Alexander Macmillan as a public forum for scientific innovations. The mid-20th century facilitated an editorial expansion for the journal; ''Nature'' redoubled its efforts in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypodermic Needle
A hypodermic needle (from Greek ὑπο- (''hypo-'' = under), and δέρμα (''derma'' = skin)), one of a category of medical tools which enter the skin, called sharps, is a very thin, hollow tube with one sharp tip. It is commonly used with a syringe, a hand-operated device with a plunger, to inject substances into the body (e.g., saline solution, solutions containing various drugs or liquid medicines) or extract fluids from the body (e.g., blood). Large-bore hypodermic intervention is especially useful in catastrophic blood loss or treating shock. A hypodermic needle is used for rapid delivery of liquids, or when the injected substance cannot be ingested, either because it would not be absorbed (as with insulin), or because it would harm the liver. It is also useful to deliver certain medications that cannot be delivered orally due to vomiting. There are many possible routes for an injection, with intramuscular (into a muscle) and intravenous (into a vein) being th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arthropod
Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a Segmentation (biology), segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and Arthropod cuticle, cuticle made of chitin, often Mineralization (biology), mineralised with calcium carbonate. The arthropod body plan consists of segments, each with a pair of appendages. Arthropods are bilaterally symmetrical and their body possesses an exoskeleton, external skeleton. In order to keep growing, they must go through stages of moulting, a process by which they shed their exoskeleton to reveal a new one. Some species have wings. They are an extremely diverse group, with up to 10 million species. The haemocoel, an arthropod's internal cavity, through which its haemolymph – analogue of blood – circulates, accommodates its interior Organ (anatomy), organs; it has an open circulatory system. Like their exteriors, the internal or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligotrophic
An oligotroph is an organism that can live in an environment that offers very low levels of nutrients. They may be contrasted with copiotrophs, which prefer nutritionally rich environments. Oligotrophs are characterized by slow growth, low rates of metabolism, and generally low population density. Oligotrophic environments are those that offer little to sustain life. These environments include deep oceanic sediments, caves, glacial and polar ice, deep subsurface soil, aquifers, ocean waters, and leached soils. Examples of oligotrophic organisms are the cave-dwelling olm; the bacterium " ''Candidatus'' Pelagibacter communis", which is the most abundant organism in the oceans with an estimated 2 × 1028 individuals in total; and the lichens with their extremely low metabolic rate. Etymologically, the word "oligotroph" is a combination of the Greek adjective ''oligos'' (ὀλίγος) meaning "few" and the adjective ''trophikos'' (τροφικός)) meaning "feeding". Plant adapta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smithsonian Institution
The Smithsonian Institution ( ), or simply the Smithsonian, is a group of museums and education and research centers, the largest such complex in the world, created by the U.S. government "for the increase and diffusion of knowledge". Founded on August 10, 1846, it operates as a trust instrumentality and is not formally a part of any of the three branches of the federal government. The institution is named after its founding donor, British scientist James Smithson. It was originally organized as the United States National Museum, but that name ceased to exist administratively in 1967. Called "the nation's attic" for its eclectic holdings of 154 million items, the institution's 19 museums, 21 libraries, nine research centers, and zoo include historical and architectural landmarks, mostly located in the District of Columbia. Additional facilities are located in Maryland, New York, and Virginia. More than 200 institutions and museums in 45 states,States without Smithsonian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Old Dominion University
Old Dominion University (Old Dominion or ODU) is a public research university in Norfolk, Virginia. It was established in 1930 as the Norfolk Division of the College of William & Mary and is now one of the largest universities in Virginia with an enrollment of 24,286 students for the 2021 academic year. Old Dominion University also enrolls over 700 international students from 89 countries. Its main campus covers straddling the city neighborhoods of Larchmont, Highland Park, and Lambert's Point, approximately from Downtown Norfolk. Old Dominion University is classified among "R1: Doctoral Universities – Very high research activity". According to the National Science Foundation, ODU spent $60.3 million on research and development in 2018. It contributes nearly $2 billion annually in economic impact to the regional economy. The university offers 168 undergraduate and graduate degree programs to approximately 24,000 students across seven colleges and three schools. Old D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grand Bahama Island
Grand Bahama is the northernmost of the islands of the Bahamas, with the town of West End located east of Palm Beach, Florida. It is the third largest island in the Bahamas island chain of approximately 700 islands and 2,400 cays. The island is roughly in area and approximately long west to east and at its widest point north to south. Administratively, the island consists of the Freeport Bonded Area and the districts of East Grand Bahama and West Grand Bahama. Nearly half of the homes on the island were damaged or destroyed in early September 2019 by Hurricane Dorian. Climate Grand Bahama Island has a tropical monsoon climate, with a hot and wet season from May through October, and warm and dry season from November through April. In Freeport the summer high temperatures average , with average lows of . During the winter, the average high temperature is , and the average low is . The rainy season in the Bahamas is from May to October. The hurricane season runs from J ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tethys Sea
The Tethys Ocean ( el, Τηθύς ''Tēthús''), also called the Tethys Sea or the Neo-Tethys, was a prehistoric ocean that covered most of the Earth during much of the Mesozoic Era and early Cenozoic Era, located between the ancient continents of Gondwana and Laurasia, before the opening of the Indian and Atlantic oceans during the Cretaceous Period. It was preceded by the Paleo-Tethys Ocean, which lasted between the Cambrian and the Early Triassic, while the Neotethys formed during the Late Triassic and lasted until the early Eocene (about 50 million years ago) when it completely closed. A portion known as the Paratethys formed during the Late Jurassic, was isolated during the Oligocene (34 million years ago) and lasted up to the Pliocene (about 5 million years ago), when it largely dried out. Many major seas and lakes of Europe and Western Asia, including the Mediterranean Sea, the Black Sea, the Caspian Sea, and the Aral Sea are thought to be remnants of the Pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
