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Cambarus Hatfeildi
''Cambarus'' is a large and diverse genus of crayfish from the United States and Canada. The adults range in size from about 5 centimeters (2 in) up to approximately 15 centimeters (6 in). Description The genus ''Cambarus'' is the second largest freshwater crayfish genus inhabiting the Northern Hemisphere, with only sixty fewer species than the genus ''Procambarus''. Though ''Cambarus'' are varied across species, the two terminal elements that make up the male form I gonopod form ninety degree angles with the central appendage, allowing for their identification. Unlike the genus ''Procambarus'' whose first pleopod tends to have three processes at the tip, ''Cambarus'' has only one or two. ''Cambarus'' reach 17–26 mm carapace lengths in their first year, while average adult carapace length ranges from 55–62 mm. As a genus containing nearly 100 species, ''Cambarus's'' coloration is variable. ''Cambarus bartonii'' is dark brown, while species like ''Cambar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wilhelm Ferdinand Erichson
Dr Wilhelm Ferdinand Erichson (26 November 1809 in Stralsund – 18 December 1848 in Berlin) was a trained medical doctor and a German entomologist. He was the author of many articles about insects mainly in ''Archiv für Naturgeschichte''. When writing in Latin, he latinised ''Wilhelm'' to ''Guillelmus'' becoming either ''Guil. F. Erichson'' or ''G.F. Erichson.'' He wrote a paper in 1842 on insect species collected at Woolnorth in Tasmania, Australia, which was the first detailed research published on the biogeography of Australian animals and was very influential in raising scientific interest in Australian fauna. Erichson was the curator of the Coleoptera collections at the ''Museum fur Naturkunde'' in Berlin from 1834 to 1848. Erichson's Scarabaeidae classification is nearly identical to the modern one. Works *''Genera Dytiscorum''. Berlin (1832) *''Die Käfer der Mark Brandenburg''. Two volumes Berlin (1837-1839) Click for pd*''Genera et species Staphylinorum insectorum'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cambarus Dubius
''Cambarus'' is a large and diverse genus of crayfish from the United States and Canada. The adults range in size from about 5 centimeters (2 in) up to approximately 15 centimeters (6 in). Description The genus ''Cambarus'' is the second largest freshwater crayfish genus inhabiting the Northern Hemisphere, with only sixty fewer species than the genus ''Procambarus''. Though ''Cambarus'' are varied across species, the two terminal elements that make up the male form I gonopod form ninety degree angles with the central appendage, allowing for their identification. Unlike the genus ''Procambarus'' whose first pleopod tends to have three processes at the tip, ''Cambarus'' has only one or two. ''Cambarus'' reach 17–26 mm carapace lengths in their first year, while average adult carapace length ranges from 55–62 mm. As a genus containing nearly 100 species, ''Cambarus's'' coloration is variable. '' Cambarus bartonii'' is dark brown, while species like '' Cam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cambarus Aculabrum
''Cambarus aculabrum'' is a rare species of cave-dwelling crayfish known by the common name Benton county cave crayfish.''Cambarus aculabrum''. National Biological Information Infrastructure. It is native to in the United States, where it is known from only four locations. It is a federally listed of the United States.USFWS [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orconectes
''Orconectes'' is a genus of cave dwelling freshwater crayfish, endemic to suitable habitats in the eastern United States. Surface dwelling species, formerly categorised here, were moved to ''Faxonius'' in 2017. Due to their subterranean habitat, they are usually depigmented, often blind, and are long-lived. Ages of 176 years have been claimed for ''O. australis'', though this was reduced to ≤22 years in a 2012 study. Taxonomy The genus ''Orconectes'' was erected in 1872 by Edward Drinker Cope to house ''Astacus pellucidus'' (now ''Orconectes pellucidus'') and his new species, ''Orconectes inermis''. Prior to the 2017 review by Oxford university, the genus contained 85 species in 11 subgenera. The ''Faxonius ''Faxonius'' is a genus of freshwater crayfish in the family Cambaridae. There are more than 90 described species in ''Faxonius''. It includes the rusty crayfish, an invasive species in North America, and three species, ''F. virilis'', ''F. immu ...'' subgenus was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cambarus Robustus
''Cambarus robustus'', known generally as the robust crayfish or Big Water crayfish, is a species of crayfish in the family Cambaridae The Cambaridae are the largest of the four families of freshwater crayfish, with over 400 Species. Most of the species in the family are native the United States east of the Great Divide and Mexico, but fewer range north to Canada, and south to .... It is found in North America. The IUCN conservation status of ''Cambarus robustus'' is "LC", least concern, with no immediate threat to the species' survival. The population is stable. The IUCN status was reviewed in 2010. References Further reading * * * External links * Cambaridae Articles created by Qbugbot Crustaceans described in 1852 Freshwater crustaceans of North America {{Crayfish-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adult
An adult is a human or other animal that has reached full growth. In human context, the term ''adult'' has meanings associated with social and legal concepts. In contrast to a " minor", a legal adult is a person who has attained the age of majority and is therefore regarded as independent, self-sufficient, and responsible. They may also be regarded as a "major". The typical age of attaining legal adulthood is 18, although definition may vary by legal rights, country, and psychological development. Human adulthood encompasses psychological adult development. Definitions of adulthood are often inconsistent and contradictory; a person may be biologically an adult, and have adult behavior, but still be treated as a child if they are under the legal age of majority. Conversely, one may legally be an adult but possess none of the maturity and responsibility that may define an adult character. In different cultures there are events that relate passing from being a child to becomin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exoskeleton
An exoskeleton (from Greek ''éxō'' "outer" and ''skeletós'' "skeleton") is an external skeleton that supports and protects an animal's body, in contrast to an internal skeleton (endoskeleton) in for example, a human. In usage, some of the larger kinds of exoskeletons are known as " shells". Examples of exoskeletons within animals include the arthropod exoskeleton shared by chelicerates, myriapods, crustaceans, and insects, as well as the shell of certain sponges and the mollusc shell shared by snails, clams, tusk shells, chitons and nautilus. Some animals, such as the turtle, have both an endoskeleton and an exoskeleton. Role Exoskeletons contain rigid and resistant components that fulfill a set of functional roles in many animals including protection, excretion, sensing, support, feeding and acting as a barrier against desiccation in terrestrial organisms. Exoskeletons have a role in defense from pests and predators, support and in providing an attachment framework f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chitin
Chitin ( C8 H13 O5 N)n ( ) is a long-chain polymer of ''N''-acetylglucosamine, an amide derivative of glucose. Chitin is probably the second most abundant polysaccharide in nature (behind only cellulose); an estimated 1 billion tons of chitin are produced each year in the biosphere. It is a primary component of cell walls in fungi (especially basidiomycetes and filamentous fungi), the exoskeletons of arthropods such as crustaceans and insects, the radulae, cephalopod beaks and gladii of molluscs and in some nematodes and diatoms. It is also synthesised by at least some fish and lissamphibians. Commercially, chitin is extracted from the shells of crabs, shrimps, shellfishes and lobsters, which are major by-products of the seafood industry. The structure of chitin is comparable to cellulose, forming crystalline nanofibrils or whiskers. It is functionally comparable to the protein keratin. Chitin has proved useful for several medicinal, industrial and biotechnological purpos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecdysis
Ecdysis is the moulting of the cuticle in many invertebrates of the clade Ecdysozoa. Since the cuticle of these animals typically forms a largely inelastic exoskeleton, it is shed during growth and a new, larger covering is formed. The remnants of the old, empty exoskeleton are called exuviae. After moulting, an arthropod is described as ''teneral'', a ''callow''; it is "fresh", pale and soft-bodied. Within one or two hours, the cuticle hardens and darkens following a tanning process analogous to the production of leather. During this short phase the animal expands, since growth is otherwise constrained by the rigidity of the exoskeleton. Growth of the limbs and other parts normally covered by the hard exoskeleton is achieved by transfer of body fluids from soft parts before the new skin hardens. A spider with a small abdomen may be undernourished but more probably has recently undergone ecdysis. Some arthropods, especially large insects with tracheal respiration, expand thei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetic Diversity
Genetic diversity is the total number of genetic characteristics in the genetic makeup of a species, it ranges widely from the number of species to differences within species and can be attributed to the span of survival for a species. It is distinguished from ''genetic variability'', which describes the tendency of genetic characteristics to vary. Genetic diversity serves as a way for populations to adapt to changing environments. With more variation, it is more likely that some individuals in a population will possess variations of alleles that are suited for the environment. Those individuals are more likely to survive to produce offspring bearing that allele. The population will continue for more generations because of the success of these individuals. The academic field of population genetics includes several hypotheses and theories regarding genetic diversity. The neutral theory of evolution proposes that diversity is the result of the accumulation of neutral substitutions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cambarus Jonesi
''Cambarus'' is a large and diverse genus of crayfish from the United States and Canada. The adults range in size from about 5 centimeters (2 in) up to approximately 15 centimeters (6 in). Description The genus ''Cambarus'' is the second largest freshwater crayfish genus inhabiting the Northern Hemisphere, with only sixty fewer species than the genus ''Procambarus''. Though ''Cambarus'' are varied across species, the two terminal elements that make up the male form I gonopod form ninety degree angles with the central appendage, allowing for their identification. Unlike the genus ''Procambarus'' whose first pleopod tends to have three processes at the tip, ''Cambarus'' has only one or two. ''Cambarus'' reach 17–26 mm carapace lengths in their first year, while average adult carapace length ranges from 55–62 mm. As a genus containing nearly 100 species, ''Cambarus's'' coloration is variable. ''Cambarus bartonii'' is dark brown, while species like ''Cambarus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algae
Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular microalgae, such as ''Chlorella,'' ''Prototheca'' and the diatoms, to multicellular forms, such as the giant kelp, a large brown alga which may grow up to in length. Most are aquatic and autotrophic (they generate food internally) and lack many of the distinct cell and tissue types, such as stomata, xylem and phloem that are found in land plants. The largest and most complex marine algae are called seaweeds, while the most complex freshwater forms are the ''Charophyta'', a division of green algae which includes, for example, ''Spirogyra'' and stoneworts. No definition of algae is generally accepted. One definition is that algae "have chlorophyll ''a'' as their primary photosynthetic pigment and lack a sterile covering of cells around thei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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