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Desert Shrimp
''Eulimnadia texana'', the Texas clam shrimp or desert shrimp, is a species belonging to the Limnadiidae family. It is Endemism, endemic to North America. It is an arid land specialist, living for many years as a cyst and bursting into life at the arrival of rains, maturing rapidly in temporary pools and producing eggs that can remain dormant until the next rains occur, perhaps in many years time. Description Desert shrimps are sexual dimorphism, sexually dimorphic. The males have their front two pairs of thoracic appendages modified into claws while the hermaphrodites have unmodified legs. Distribution and habitat Desert shrimps live in ditches, ponds, pools, and other ephemeral freshwater habitats in northern Outline of Mexico, Mexico and parts of the southern United States, southern and southwestern United States, west of the Mississippi River. Biology Individual shrimps are either male or hermaphrodite. The hermaphrodites can fertilize their own eggs or can mate with males ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpheus Spring Packard
Alpheus Spring Packard Jr. LL.D. (February 19, 1839 – February 14, 1905) was an American entomologist and palaeontologist. He described over 500 new animal species – especially butterflies and moths – and was one of the founders of ''The American Naturalist''.Cockerell (1920) Early life He was the son of Alpheus Spring Packard Sr. (1798–1884) and the brother of William Alfred Packard. He was born in Brunswick, Maine, and was Professor of Zoology and Geology at Brown University in Providence, Rhode Island, from 1878 until his death. He was a vocal proponent of Neo-Lamarckism during the eclipse of Darwinism.Sorenson (1995) Career & Works His chief work was the classification and anatomy of arthropods, and contributions to economic entomology, zoogeography, and the phylogeny and metamorphoses of insects. Packard was appointed to the United States Entomological Commission in 1877 where he served with Charles Valentine Riley and Cyrus Thomas.Mallis (1971) He wrote school text ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biogeography
Biogeography is the study of the distribution of species and ecosystems in geographic space and through geological time. Organisms and biological communities often vary in a regular fashion along geographic gradients of latitude, elevation, isolation and habitat area.Brown University, "Biogeography." Accessed February 24, 2014. . Phytogeography is the branch of biogeography that studies the distribution of plants. Zoogeography is the branch that studies distribution of animals. Mycogeography is the branch that studies distribution of fungi, such as mushrooms. Knowledge of spatial variation in the numbers and types of organisms is as vital to us today as it was to our early human ancestors, as we adapt to heterogeneous but geographically predictable environments. Biogeography is an integrative field of inquiry that unites concepts and information from ecology, evolutionary biology, taxonomy, geology, physical geography, palaeontology, and climatology.Dansereau, Pierre. 1957 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spinicaudata
Clam shrimp are a group of bivalved branchiopod crustaceans that resemble the unrelated bivalved molluscs. They are extant and also known from the fossil record, from at least the Devonian period and perhaps before. They were originally classified in the former order Conchostraca, which later proved to be paraphyletic and was subsumed into the superorder Diplostraca. Clam shrimp now make up three of the seven orders in Diplostraca, Cyclestherida, Laevicaudata, and Spinicaudata, in addition to the fossil family Leaiidae. Characteristics Both valves of the shell are held together by a strong closing muscle. The animals react to danger by contracting the muscle, so that the valves close tightly and the crustacean, as if dead, lies motionlessly at the bottom of the pool. In most species the head is dorsoventrally compressed. The sessile compound eyes are close together and located on the forehead; in the genus ''Cyclestheria'' they are truly fused. In front of them is a simple ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metamorphosis
Metamorphosis is a biological process by which an animal physically develops including birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation. Some insects, fish, amphibians, mollusks, crustaceans, cnidarians, echinoderms, and tunicates undergo metamorphosis, which is often accompanied by a change of nutrition source or behavior. Animals can be divided into species that undergo complete metamorphosis (" holometaboly"), incomplete metamorphosis ("hemimetaboly"), or no metamorphosis (" ametaboly"). Scientific usage of the term is technically precise, and it is not applied to general aspects of cell growth, including rapid growth spurts. Generally organisms with a larva stage undergo metamorphosis, and during metamorphosis the organism loses larval characteristics. References to "metamorphosis" in mammals are imprecise and only colloquial, but historically idealist ideas of transformation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nauplius (larva)
Crustaceans may pass through a number of larval and immature stages between hatching from their eggs and reaching their adult form. Each of the stages is separated by a ecdysis, moult, in which the hard exoskeleton is shed to allow the animal to grow. The larvae of crustaceans often bear little resemblance to the adult, and there are still cases where it is not known what larvae will grow into what adults. This is especially true of crustaceans which live as benthic adults (on the sea bed), more-so than where the larvae are planktonic, and thereby easily caught. Many crustacean larvae were not immediately recognised as larvae when they were discovered, and were described as new genera and species. The names of these genera have become generalised to cover specific larval stages across wide groups of crustaceans, such as ''zoea'' and ''nauplius''. Other terms described forms which are only found in particular groups, such as the ''glaucothoe'' of hermit crabs, or the ''phyllosoma'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Egg (biology)
An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote) and to incubate from it an embryo within the egg until the embryo has become an animal fetus that can survive on its own, at which point the animal hatches. Most arthropods such as insects, vertebrates (excluding live-bearing mammals), and mollusks lay eggs, although some, such as scorpions, do not. Reptile eggs, bird eggs, and monotreme eggs are laid out of water and are surrounded by a protective shell, either flexible or inflexible. Eggs laid on land or in nests are usually kept within a warm and favorable temperature range while the embryo grows. When the embryo is adequately developed it hatches, i.e., breaks out of the egg's shell. Some embryos have a temporary egg tooth they use to crack, pip, or break the eggshell or covering. The largest recorded egg is from a whale shark and was in size. Whale shark eggs typically hatch within the mother. At and up to , the o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mojave Desert
The Mojave Desert ( ; mov, Hayikwiir Mat'aar; es, Desierto de Mojave) is a desert in the rain shadow of the Sierra Nevada mountains in the Southwestern United States. It is named for the indigenous Mojave people. It is located primarily in southeastern California and southwestern Nevada, with small portions extending into Arizona and Utah. The Mojave Desert, together with the Sonoran, Chihuahuan, and Great Basin deserts, forms a larger North American Desert. Of these, the Mojave is the smallest and driest. The Mojave Desert displays typical basin and range topography, generally having a pattern of a series of parallel mountain ranges and valleys. It is also the site of Death Valley, which is the lowest elevation in North America. The Mojave Desert is often colloquially called the "high desert", as most of it lies between . It supports a diversity of flora and fauna. The desert supports a number of human activities, including recreation, ranching, and military training. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Filter Feeder
Filter feeders are a sub-group of suspension feeding animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized filtering structure. Some animals that use this method of feeding are clams, krill, sponges, baleen whales, and many fish (including some sharks). Some birds, such as flamingos and certain species of duck, are also filter feeders. Filter feeders can play an important role in clarifying water, and are therefore considered ecosystem engineers. They are also important in bioaccumulation and, as a result, as indicator organisms. Fish Most forage fish are filter feeders. For example, the Atlantic menhaden, a type of herring, lives on plankton caught in midwater. Adult menhaden can filter up to four gallons of water a minute and play an important role in clarifying ocean water. They are also a natural check to the deadly red tide. Extensive article on the role of menhaden in the ecosystem and possible resul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Omnivore
An omnivore () is an animal that has the ability to eat and survive on both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize the nutrients and energy of the sources absorbed. Often, they have the ability to incorporate food sources such as algae, fungi, and bacteria into their diet. Omnivores come from diverse backgrounds that often independently evolved sophisticated consumption capabilities. For instance, dogs evolved from primarily carnivorous organisms ( Carnivora) while pigs evolved from primarily herbivorous organisms (Artiodactyla). Despite this, physical characteristics such as tooth morphology may be reliable indicators of diet in mammals, with such morphological adaptation having been observed in bears. The variety of different animals that are classified as omnivores can be placed into further sub-categories depending on their feeding behaviors. Frugivor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biological Sciences
Biology is the scientific study of life. It is a natural science with a broad scope but has several unifying themes that tie it together as a single, coherent field. For instance, all organisms are made up of cells that process hereditary information encoded in genes, which can be transmitted to future generations. Another major theme is evolution, which explains the unity and diversity of life. Energy processing is also important to life as it allows organisms to move, grow, and reproduce. Finally, all organisms are able to regulate their own internal environments. Biologists are able to study life at multiple levels of organization, from the molecular biology of a cell to the anatomy and physiology of plants and animals, and evolution of populations.Based on definition from: Hence, there are multiple subdisciplines within biology, each defined by the nature of their research questions and the tools that they use. Like other scientists, biologists use the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eulimnadia
''Eulimnadia'' is a genus of branchiopods in the family Limnadiidae. There are about 13 described species in ''Eulimnadia''. Species * ''Eulimnadia agassizii'' Packard, 1874 * ''Eulimnadia antillarum'' (Baird, 1852) * ''Eulimnadia antlei'' Mackin, 1940 * ''Eulimnadia astraova'' Belk, 1989 * ''Eulimnadia cylindrova'' Belk, 1989 * ''Eulimnadia diversa'' Mattox, 1937 * ''Eulimnadia francescae'' * ''Eulimnadia inflecta'' * ''Eulimnadia oryzae'' * ''Eulimnadia stoningtonensis'' * ''Eulimnadia texana'' (Packard, 1871) * '' Eulimnadia thompsoni'' * ''Eulimnadia ventricosa ''Eulimnadia'' is a genus of branchiopods in the family Limnadiidae. There are about 13 described species in ''Eulimnadia''. Species * ''Eulimnadia agassizii'' Packard, 1874 * ''Eulimnadia antillarum'' (Baird, 1852) * ''Eulimnadia antlei'' Macki ...'' References Further reading * Diplostraca Branchiopoda genera {{branchiopoda-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleontology
Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene epoch (roughly 11,700 years before present). It includes the study of fossils to classify organisms and study their interactions with each other and their environments (their paleoecology). Paleontological observations have been documented as far back as the 5th century BC. The science became established in the 18th century as a result of Georges Cuvier's work on comparative anatomy, and developed rapidly in the 19th century. The term itself originates from Greek (, "old, ancient"), (, ( gen. ), "being, creature"), and (, "speech, thought, study"). Paleontology lies on the border between biology and geology, but differs from archaeology in that it excludes the study of anatomically modern humans. It now uses techniques drawn from a wide range of sciences, including biochemistry, mathematics, and engineering. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
