Achilles, in Greek mythology, son of the mortal Peleus, king of the Myrmidons, and the Nereid, or sea nymph, Thetis. Achilles was the bravest, handsomest, and greatest warrior of the army of Agamemnon in the Trojan War. According to Homer, Achilles was brought up by his mother at Phthia with his

Max Wolf: In 1906 he discovered Achilles, the first of the Trojan planets, two groups of asteroids that move around the Sun in Jupiter’s orbit: one group 60° ahead of Jupiter, the other 60° behind.

Miroslav Holub: …additional collections by 1971, including Achilles a želva (1960; “Achilles and the Tortoise”), Tak zvané srdce (1963; “The So-Called Heart”), and Ačkoli (1969; Although).

Achilles Painter: …with a painting of “Achilles and Briseis.” The amphora is now in the Vatican Museums. His period of activity coincides with the Parthenon sculptures and with the administration of Pericles.

Achilles Painter was an Athenian vase painter known by and named for an amphora attributed to him with a painting of “Achilles and Briseis.” The amphora is now in the Vatican Museums. His period of activity coincides with the Parthenon sculptures and with the administration of Pericles. The

Achilles paradox, in logic, an argument attributed to the 5th-century-bce Greek philosopher Zeno, and one of his four paradoxes described by Aristotle in the treatise Physics. The paradox concerns a race between the fleet-footed Achilles and a slow-moving tortoise. The two start moving at the same

Achilles Tatius was the author of Leucippe and Cleitophon, one of the Greek prose romances that influenced the development of the novel centuries later. Nothing certain is known of Achilles’ life. Some Byzantine sources called him a rhetor (“teacher of rhetoric”). In the Suda lexicon of the 10th

Achilles tendon, strong tendon at the back of the heel that connects the calf muscles to the heel. The tendon is formed from the gastrocnemius and soleus muscles (the calf muscles) and is inserted into the heel bone. The contracting calf muscles lift the heel by this tendon, thus producing a foot

Achilles: …she held him—the proverbial “Achilles’ heel.”

Alessandro Achillini was an Italian philosopher and physician, an advocate of the teachings of William of Ockham. Achillini was educated at the University of Bologna, where he taught philosophy and medicine from 1484 to 1512, except for two years at Padua. Although sometimes classed as a strict

Aceh, autonomous daerah istimewa (special district) of Indonesia, with the status of propinsi (or provinsi; province), forming the northern extremity of the island of Sumatra. Aceh is surrounded by water on three sides: the Indian Ocean to the west and north and the Strait of Malacca to the east.

Acehnese, one of the main ethnic groups on the island of Sumatra, Indonesia. They were estimated to number roughly 4.2 million in the early 21st century. They speak a language of the Austronesian (Malayo-Polynesian) family. The Acehnese were ruled by Indian princes prior to 500 ce, and in the 13th

Austronesian languages: Major languages: Acehnese, Balinese, and Buginese of western Indonesia; and Malagasy of Madagascar. Each of these languages has more than one million speakers. Javanese alone accounts for about one-quarter of all speakers of Austronesian languages, which is a remarkable disparity in view of the total number of…

Acehnese War, (1873–1904), an armed conflict between the Netherlands and the Muslim sultanate of Aceh (also spelled Acheh, or Atjeh) in northern Sumatra that resulted in Dutch conquest of the Acehnese and, ultimately, in Dutch domination of the entire region. In 1871 the Netherlands and Britain had

Achinsk, city, Krasnoyarsk kray (region), south-central Russia. It lies along the Chulym River, which is a tributary of the Ob. It was founded in 1621 and chartered in 1782. Important as a river-road transfer point until rail lines were constructed, it gained economic importance when an alumina

philosophy of science: Other approaches to explanation: Philosophers such as Peter Achinstein and Bas van Fraassen offered pragmatic theories, according to which what counts as an explanation is contextually determined. Their accounts remained close to the everyday practice of explaining, but, to the extent that they eschewed context-independent conditions on explanation, they encouraged a return…

canna: …Indian shot (Canna indica), and achira (C. discolor) have edible starchy rhizomes and are grown agriculturally in some places; the latter is sometimes listed as a synonym of C. indica.

pleuronectiform: Annotated classification: …20 species Family Achiridae (American soles) Eyes small, dextral; sensory papillae on head; margin of preoperculum represented by a superficial groove; dorsal and anal fins free from caudal fin; right pelvic fin attached to anal fin. 7 genera and about 30 species. Marine and freshwater, along the Atlantic and…

pleuronectiform: Annotated classification: Family Achiropsettidae (southern flounders) Eyes sinistral; body extremely compressed; pectoral fins rudimentary or absent; lateral line straight; branchiostegal membranes separate. 4 genera and 5 species; Antarctic and subantarctic seas. Family Scophthalmidae (turbots) Eyes

Hinduism: Philosophical sutras and the rise of the Six Schools of philosophy: …consisting of chit (consciousness) and achit (what is not conscious; this category includes matter and time), forms the body of brahman, or Vishnu.

Ahithophel, in the Old Testament, one of King David’s most trusted advisers. He took a leading part in the revolt of David’s son Absalom, and Ahithophel’s defection was a severe blow to David. Having consulted Ahithophel about his plans to proceed against David, Absalom then sought advice from

Walter Achiu was an American athlete who was the first person of Asian descent to play in the National Football League (NFL). In the late 1920s, he played multiple positions for the Dayton Triangles, one of the original NFL franchises. Achiu was born in Honolulu to a Chinese father and a Hawaiian

Ahmed I was an Ottoman sultan from 1603 to 1617, whose authority was weakened by wars, rebellions, and misrule. The rebellions he was able to suppress; he executed some of the viziers and exiled many palace dignitaries for bribery and intrigue, and he introduced a new regulation for the improvement

Ahmed II was an Ottoman sultan (1691–95) whose reign was marked by the continuing war with the Holy League (Austria-Poland-Venice). Soon after his accession to the throne, Ahmed’s forces were defeated by the Austrians at Slankamen, Hung. The able grand vizier (chief minister) Köprülü Fazıl Mustafa

Ahmed III was the sultan of the Ottoman Empire from 1703 to 1730. The son of Mehmed IV, he succeeded to the throne in 1703 upon the deposition of his brother Mustafa II. Ahmed III cultivated good relations with England and France and afforded refuge at his court to Charles XII of Sweden after his

Ahmed I was an Ottoman sultan from 1603 to 1617, whose authority was weakened by wars, rebellions, and misrule. The rebellions he was able to suppress; he executed some of the viziers and exiled many palace dignitaries for bribery and intrigue, and he introduced a new regulation for the improvement

Ahmed II was an Ottoman sultan (1691–95) whose reign was marked by the continuing war with the Holy League (Austria-Poland-Venice). Soon after his accession to the throne, Ahmed’s forces were defeated by the Austrians at Slankamen, Hung. The able grand vizier (chief minister) Köprülü Fazıl Mustafa

Ahmed III was the sultan of the Ottoman Empire from 1703 to 1730. The son of Mehmed IV, he succeeded to the throne in 1703 upon the deposition of his brother Mustafa II. Ahmed III cultivated good relations with England and France and afforded refuge at his court to Charles XII of Sweden after his

Gibraltar: …two peaks in northern Africa: Mount Hacho, near the city of Ceuta (the Spanish exclave on the Moroccan coast), or Jebel Moussa (Musa), in Morocco. The Pillars—which, according to Homer, were created when Heracles broke the mountain that had connected Africa and Europe—defined the western limits of navigation for the…

Acholi, ethnolinguistic group of northern Uganda and South Sudan. Numbering more than one million at the turn of the 21st century, they speak a Western Nilotic language of the Eastern Sudanic branch of the Nilo-Saharan family and are culturally and historically related to their traditional enemies,

achondrite, any stony meteorite containing no chondrules (small, roughly spherical objects that formed in the solar nebula). The only exclusions are carbonaceous chondrites of the CI group, which, though they are clearly chondrites, are so heavily altered by water that any evidence for their having

achondroplasia, genetic disorder characterized by an abnormality in the conversion of cartilage into bone. As a consequence, bones that depend on cartilage models for development, particularly long bones such as the femur and humerus, cannot grow. Achondroplasia is the most common cause of

ancient Egypt: The 28th, 29th, and 30th dynasties: Achoris (ruled 393–380 bce), its third ruler, was especially vigorous, and the prosperity of his reign is indicated by many monuments in Upper and Lower Egypt. Once again Egypt was active in international politics, forming alliances with the opponents of Persia and building up its…

Rainforest Regeneration in Panama: …are tree species such as Manilkara, almendro, and the suicide tree, characterized by slower growth and lower light requirements, with the capacity for extended persistence under low light conditions. Such trees tend toward high wood densities, relatively delayed attainment of reproductive status, and larger, often animal-dispersed seeds. They also have…

sapodilla, (Manilkara zapota), tropical evergreen tree (family Sapotaceae) and its distinctive fruit, native to southern Mexico, Central America, and parts of the Caribbean. Though of no great commercial importance in any part of the world, the sapodilla is much appreciated in many tropical and

beekeeping: Pests: The larvae of the lesser wax moth, Achroia grisella, cause damage to stored combs similar to that of the greater wax moth. The Mediterranean flour moth larva, Anagasta kuehniella, feeds on pollen in the combs and causes some damage. Control for both of these moths is the same as…

tourmaline: …(Brazilian emerald), or colourless (achroite). Some crystals are pink at one end and green at the other; concentric colour zoning may also occur. The coloured varieties, when transparent and free from flaws, are cut as gems.

biology: The discovery of cells: …solved until the invention of achromatic lenses, which were introduced about 1830. In 1878 a modern achromatic compound microscope was produced from the design of the German physicist Ernst Abbe. Abbe subsequently designed a substage illumination system, which, together with the introduction of a new substage condenser, paved the way…

colour: Tristimulus measurement and chromaticity diagrams: The achromatic point is the central point at x = 13, y = 13 (shown as W in the figure), where visually perceived white is located (as well as the pure grays and black, which vary only in the magnitude of the luminance Y).

bacteria: Diversity of structure of bacteria: …5 μm or more; and Achromatium, which has a minimum width of 5 μm and a maximum length of 100 μm, depending on the species. Giant bacteria can be visible with the unaided eye, such as Thiomargarita namibiensis, which averages 750 μm in diameter; T. magnifica, which averages 700 μm…

colour blindness: Types of colour blindness: …conditions are rare and include achromatopsia (or rod monochromacy; the complete absence of functional cone photopigments) and cone monochromacy (when two of the three cone types are nonfunctional).

Gerrit Achterberg was a Dutch poet whose use of surreal language and imagery influenced a generation of post-World War II poets known as the Experimentalists. His verse, traditional in form, is characterized as romantic and metaphysical. He was a linguistic innovator, often coining new words based

Gelderland: …on the west and the Achterhoek on the east. The hill plateau of the Veluwe is covered with scantily cultivated heaths and some woods, of primarily fir and beech. There are two national parks (Hoge Veluwe and Veluwezoom) and a wildlife reserve. Much of the Veluwe is used for military…

The Diary of a Young Girl, journal by Anne Frank, a Jewish teenager who chronicled her family’s two years (1942–44) in hiding during the German occupation of the Netherlands during World War II. The book was first published in 1947—two years after Anne’s death in a concentration camp—and later

U2: …in 1991 with the album Achtung Baby and a sound heavily influenced by European experimental, electronic, and disco music. With this came a stage show that trafficked in irony and self-deprecating humour, qualities virtually absent from the band’s music in the previous decade; the 1992 Zoo TV tour was one…

Heinz Guderian: His Achtung! Panzer! (1937; Attention! Tanks!) incorporated many of the theories of the British general J.F.C. Fuller and General Charles de Gaulle, who advocated the creation of independent armoured formations with strong air and motorized infantry support, intended to increase mobility on the battlefield by quick penetrations of enemy…

Karl Marx: Early years in London of Karl Marx: …Brumaire des Louis Napoleon” (The Eighteenth Brumaire of Louis Bonaparte), with its acute analysis of the formation of a bureaucratic absolutist state with the support of the peasant class. In other respects the next 12 years were, in Marx’s words, years of “isolation” both for him and for Engels…

Billy Ray Cyrus: …for his 1992 song “Achy Breaky Heart,” a smash hit that crossed over to the pop charts and inspired a line dancing craze. He also acted in several television series, including Hannah Montana (2006–11), a family-friendly show that launched the career of his daughter, the actress and singer Miley…

India: Renewed decentralization: …and picked his half brother Achyuta Deva Raya (reigned 1529–42) to succeed him. Following a brief succession dispute, Achyuta Deva Raya was able to reach the capital from Chandragiri, where Krishna Deva had kept him and other princes confined, and to ascend the throne. Although he probably was not as…

mineral: Crystal habit and crystal aggregation: …slender fibres, parallel or radiating; acicular, slender, needlelike crystals; radiating, individuals forming starlike or circular groups; globular, radiating individuals forming small spherical or hemispherical groups; dendritic, in slender divergent branches, somewhat plantlike; mammillary, large smoothly rounded, masses resembling mammae, formed by radiating crystals; botryoidal,

acid, any substance that in water solution tastes sour, changes the colour of certain indicators (e.g., reddens blue litmus paper), reacts with some metals (e.g., iron) to liberate hydrogen, reacts with bases to form salts, and promotes certain chemical reactions (acid catalysis). Examples of acids

chemical compound: Carboxylic acids: …chlorine or bromine atom; and anhydrides have an attached carboxyl group. Each type of acid derivative has a set of characteristic reactions that qualifies it as a unique functional group, but all acid derivatives can be readily converted to a carboxylic acid under appropriate reaction conditions. Many simple esters are…

Thomas Mapfumo: In 1976 Mapfumo formed the Acid Band, which produced a blend of popular and traditional music as a vehicle to carry thinly veiled political messages; that music was called chimurenga (Shona: “struggle”). The band’s first album, released in 1977, was titled Hokoyo! (“Watch Out!”).

printmaking: Acids and the etching process: The acid bite of the plate is a critical stage in the making of an etching. The printmaker must be familiar with the characteristics of the materials that are being used. On a zinc plate nitric acid is used. In the process of biting, this acid…

dye: Azo dyes: Acid Black 1 is formed by coupling first to diazotized p-nitroaniline in weakly acidic solution and then to diazotized aniline in alkaline solution.

carboxylic acid: Acyl halides: The functional group of an acyl halide (acid halide) is an acyl group (RCO―) bonded to a halogen atom. They are named by changing the suffix -ic acid in the name of the parent carboxylic acid to -yl halide. Because…

acid rain, precipitation possessing a pH of about 5.2 or below primarily produced from the emission of sulfur dioxide (SO2) and nitrogen oxides (NOx; the combination of NO and NO2) from human activities, mostly the combustion of fossil fuels. In acid-sensitive landscapes, acid deposition can reduce

acid dye, any bright-coloured synthetic organic compound whose molecule contains two groups of atoms—one acidic, such as a carboxylic group, and one colour-producing, such as an azo or nitro group. Acid dyes are usually applied in the form of their sodium salts, chiefly on wool but also on silk

acid halide, neutral compound that reacts with water to produce an acid and a hydrogen halide. Acid halides are ordinarily derived from acids or their salts by replacement of hydroxyl groups by halogen atoms. The most important organic acid halides are the chlorides derived from carboxylic acids

Daft Punk: …of house music known as acid house. Their debut album, Homework (1997), won them further acclaim within the dance music scene, and the buoyant single “Around the World”—which featured a looped, electronically processed vocal—helped introduce the act to a wider audience.

lysosome: …variety of hydrolytic enzymes (acid hydrolases) that break down macromolecules such as nucleic acids, proteins, and polysaccharides. These enzymes are active only in the lysosome’s acidic interior; their acid-dependent activity protects the cell from self-degradation in case of lysosomal leakage or rupture, since the pH of the cell is…

nutritional disease: Heartburn and peptic ulcer: When gastric contents, containing hydrochloric acid, flow backward from the stomach, the lining of the esophagus becomes inflamed, leading to the burning sensation known as heartburn. Occasional heartburn (also known as acid indigestion) is a common occurrence, typically

uranium processing: Leaching: Acid leaching is commonly performed by agitating an ore-leach mixture for 4 to as long as 48 hours at ambient temperature. Except in special circumstances, sulfuric acid is the leachant used; it is supplied in amounts sufficient to obtain a final leach liquor at about…

lead processing: The metal and its alloys: Acid lead, made by adding copper to fully refined lead, differs from chemical lead primarily in its higher bismuth content.

Pompe’s disease, hereditary defect in the body’s ability to metabolize glycogen, resulting in a muscle disorder that is usually fatal during the first year of life. The defect responsible, absence of the enzyme alpha-1,4-glucosidase, is extremely rare, occurring in fewer than one in every 150,000

enzyme analysis: …hepatitis and obstructive jaundice; (4) acid phosphatase, an enzyme found in most body tissue but in unusually high concentration in the adult prostate gland; it is released into the circulation in metastatic cancer of the prostate; (5) peptidases, a group of enzyme-digesting proteins found in greater concentrations in the serum…

acid rain, precipitation possessing a pH of about 5.2 or below primarily produced from the emission of sulfur dioxide (SO2) and nitrogen oxides (NOx; the combination of NO and NO2) from human activities, mostly the combustion of fossil fuels. In acid-sensitive landscapes, acid deposition can reduce

acid rain, precipitation possessing a pH of about 5.2 or below primarily produced from the emission of sulfur dioxide (SO2) and nitrogen oxides (NOx; the combination of NO and NO2) from human activities, mostly the combustion of fossil fuels. In acid-sensitive landscapes, acid deposition can reduce

emissions trading: Acid rain and greenhouse gases: …large-scale practical application in the Acid Rain Program run by the U.S. Environmental Protection Agency in the 1990s. In 1990, amendments to the U.S. Clean Air Act of 1970 called for a halving of emissions of sulfur dioxide (SO2) within two decades, along with a parallel ambitious reduction in emissions…

felsic and mafic rocks, division of igneous rocks on the basis of their silica content. Chemical analyses of the most abundant components in rocks usually are presented as oxides of the elements; igneous rocks typically consist of approximately 12 major oxides totaling over 99 percent of the rock.

acid-base catalysis, acceleration of a chemical reaction by the addition of an acid or a base, the acid or base itself not being consumed in the reaction. The catalytic reaction may be acid-specific (acid catalysis), as in the case of decomposition of the sugar sucrose into glucose and fructose in

acid–base reaction: Acid–base equilibria: Certain general principles apply to any solvent with both acidic and basic properties—for example, water, alcohols, ammonia, amines, and acetic acid. Denoting the solvent molecule by SH, proton transfer can give rise to the ions SH2+ and S−, sometimes called lyonium and lyate…

acid–base reaction, a type of chemical process typified by the exchange of one or more hydrogen ions, H+, between species that may be neutral (molecules, such as water, H2O; or acetic acid, CH3CO2H) or electrically charged (ions, such as ammonium, NH4+; hydroxide, OH−; or carbonate, CO32−). It also

titration: …the sample and titrant, include: acid-base titrations, precipitation titrations, complex-formation titrations, and oxidation-reduction (redox) titrations. In acid-base titration (i.e., the titration of an acid with a base, or vice versa), the indicator is a substance that can exist in two forms, an acid form and a basic form, which differ…

lead processing: The metal and its alloys: Acid lead, made by adding copper to fully refined lead, differs from chemical lead primarily in its higher bismuth content.

Mars: Sparsely cratered plains: These include Chryse Planitia and Acidalia Planitia (centered on 30° W longitude), Amazonis Planitia (160° W), and Utopia Planitia (250° W). The only significant relief in this huge area is a large ancient impact basin, informally called the Utopia basin (40° N, 250° W).

bacteria: pH: …sulfide deposits are attacked by A. ferrooxidans to generate sulfuric acid, which lowers the pH to 2.0 or even 0.7. However, acid tolerance of A. ferrooxidans applies only to sulfuric acid, since these bacteria die when exposed to equivalent concentrations of other acids such as hydrochloric acid. Many bacteria cannot…

buffer: …the ionization constant of acetic acid and the expressions in brackets are the concentrations of the respective substances. The hydrogen ion concentration of the buffer solution is dependent on the relative amounts of acetic acid and acetate ion (or sodium acetate) present, known as the buffer ratio. The addition of…

acid–base reaction: Acid–base equilibria: …quantity pKa, sometimes called the acidity exponent, and defined by the relation pKa = −log10Ka. Values of pKa are generally of a more convenient magnitude.

acid–base reaction: Concentrated aqueous acids: …is commonly measured by the acidity function, H0, a quantity measured by the effect of the solvent on a basic indicator I. It is defined by H0 + pKih+ − log10 [IH+]/[I] and becomes equal to the pH in dilute solution. The acidity function H0 frequently is found to be…

extremophile: …organisms may be described as acidophilic (optimal growth between pH 1 and pH 5); alkaliphilic (optimal growth above pH 9); halophilic (optimal growth in environments with high concentrations of salt); thermophilic (optimal growth between 60 and 80 °C [140 and 176 °F]); hyperthermophilic (optimal growth above 80 °C [176 °F]);…

extremophile: …organisms may be described as acidophilic (optimal growth between pH 1 and pH 5); alkaliphilic (optimal growth above pH 9); halophilic (optimal growth in environments with high concentrations of salt); thermophilic (optimal growth between 60 and 80 °C [140 and 176 °F]); hyperthermophilic (optimal growth above 80 °C [176 °F]);…

acidosis, abnormally high level of acidity, or low level of alkalinity, in the body fluids, including the blood. There are two primary types of acidosis: respiratory acidosis and metabolic acidosis. Respiratory acidosis results from inadequate excretion of carbon dioxide from the lungs. This may be

Brønsted-Lowry theory, a theory, introduced independently in 1923 by the Danish chemist Johannes Nicolaus Brønsted and the English chemist Thomas Martin Lowry, stating that any compound that can transfer a proton to any other compound is an acid, and the compound that accepts the proton is a base.

Cassandre: …he designed two other typefaces, Acier Noir (1935) and Piegnot (1937). In 1939 he abandoned poster art and henceforth devoted himself to designing stage sets and to painting.

pottery: Porcelain: …by the figure modelling of Michel Victor Acier, who came to the factory to share the position of Modellmeister with Kändler in 1764. From 1774 to 1814 the Neoclassical style was increasingly used, and the designs of Sèvres and of Wedgwood (Wedgwoodarbeit) were copied.

Luxembourg: Manufacturing and trade: …the late 1970s ARBED (Aciéries Réunies de Burbach-Eich-Dudelange) SA was Luxembourg’s only remaining steelmaker. In 2001 ARBED merged with the Spanish company Aceralia and the French company Usinor to form Arcelor, which subsequently joined Mittal to create ArcelorMittal, the world’s largest steel company at the time of its formation…

epigraphy: Ancient Rome: …bce; pieces of the laws Lex Acilia Repetundarum (123 bce) and Lex Agraria (111 bce) were found in the 16th century on opposite sides of what was once a large bronze tablet; the local laws of the town of Bantia (on the borderlands of Lucania and Apulia in southern Italy)…

Marcus Porcius Cato: …Cato served with distinction under Manius Acilius Glabrio at Thermopylae in the war against the Seleucid king Antiochus III. Shortly thereafter he included Glabrio in his denunciation of the supporters of the Scipios. He then attacked Lucius Scipio and Scipio Africanus the Elder and broke their political influence. This success…

pharmaceutical industry: Isolation of insulin: …destroyed by enzymes from the acinar cells. By this time Banting had enlisted the support of Charles H. Best, a fourth-year medical student. Together they tied off the pancreatic ducts through which acinar cells release the digestive enzymes. This insult caused the acinar cells to die. Subsequently, the remainder of…

Ronda, town, Málaga provincia (province), in the Andalusia comunidad autónoma (autonomous community), southern Spain. It lies in the Ronda Mountains west of Málaga city. The town is situated on two hills divided by a deep ravine (El Tajo de Ronda) containing the Grande River, which is an affluent

feline: Evolution and classification: Acinonychinae Genus Acinonyx (cheetah) 1 almost exclusively African species. Assorted ReferencesAmazon Rain Forestclassification and characteristics

cheetah, (Acinonyx jubatus), one of the world’s most-recognizable cats, known especially for its speed. Cheetahs’ sprints have been measured at a maximum of 114 km (71 miles) per hour, and they routinely reach velocities of 80–100 km per hour while pursuing prey. Nearly all the cheetahs remaining

Achinsk, city, Krasnoyarsk kray (region), south-central Russia. It lies along the Chulym River, which is a tributary of the Ob. It was founded in 1621 and chartered in 1782. Important as a river-road transfer point until rail lines were constructed, it gained economic importance when an alumina

respiratory disease: Morphological classification of respiratory disease: …terminal bronchiole opens into an acinus, so called because the structure resembles a cluster of grapes, and from this point onward the gas-exchanging portion of the lung is reached. The alveoli, or air sacs, which are divided into groups or lobules by fibrous partitions, or septa, are small hexagonal structures…

chondrostean: Distribution: The Baikal sturgeon (A. baerii) occurs in Lake Baikal and in nearby regions of Russia (Siberia), China, and Kazakhstan. A smaller species, the sterlet (A. ruthenus), inhabits the Black and Caspian seas. The starry

chondrostean: Distribution: The lake sturgeon of North America (A. fulvescens) occurs in the Mississippi River valley, in Lake Huron, and northward into Canada. The white, Oregon, or Sacramento sturgeon (A. transmontanus) inhabits the waters of the Pacific coast of North America from California to

sturgeon: Distribution: The Russian sturgeon, A. guldenstadtii, is one of the most valuable species inhabiting the rivers of Russia and occurs eastward to Lake Baikal. It is about the same size as the common sturgeon and is found particularly in the rivers feeding the Black and Caspian seas.…

hausen, large species of sturgeon

chondrostean: Distribution: A closely related form (A. oxyrinchus) is found along the east coast of North America from the St. Lawrence River to the Gulf of Mexico. The Baikal sturgeon (A. baerii) occurs in Lake Baikal and in nearby regions of Russia (Siberia), China, and Kazakhstan. A