Science and Technology

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Entry Category: Science and Technology - Starting with C

Caddisflies

aka: Trichopterans
Caddisflies (Phylum Arthropoda, Class Insecta, Order Trichoptera) make up the largest and most diverse group of aquatic insects. More specifically, caddisflies are a group of small to medium-sized (2 to 30 mm in length), moth-like insects with two pairs of hairy membranous wings; they have aquatic larval forms that metamorphose into terrestrial adults. The name for the order Trichoptera comes from the name Trichos, which means “hairy,” and ptera, which means “wings.” The word “caddis” dates back to The Compleat Angler, written by Izaak Walton (1594–1683) and published in 1653, in which “cod-worms or caddis” were named as being used for bait. Caddisflies are a favorite food of many fish, and therefore are attractive to anglers, particularly trout fly fishermen, …

Caddo Mountain Salamander

aka: Plethodon caddoensis
The Caddo Mountain salamander (Plethodon caddoensis) is a slender, medium-sized (90–100 millimeters in total length) terrestrial salamander. It is one of twenty or so members of the caudate family Plethodontidae that can be found in Arkansas. Adults of this species possess numerous tiny white spots and/or brassy flecks on the back and tail; the dorsal body color is otherwise uniformly black. The lateral body surfaces are creamy white in appearance. The throat region is distinctly pale or white. Juveniles may lack much of the lateral body coloration. This species is one of three endemic salamanders known to exist in Arkansas and is primarily confined to the Caddo Mountains area of the southern Ouachita National Forest and several outlying areas in …

Carpenter Dam

aka: Lake Hamilton
Carpenter Dam is the second of three dams constructed along the Ouachita River in the vicinity of Hot Springs (Garland County), following Remmel Dam (completed in 1924) and preceding Blakely Mountain Dam (completed in the 1950s). The concrete gravity dam was built by Arkansas Power and Light (AP&L), which later became Entergy, for purposes of producing hydroelectric power. It impounds the 7,200-acre Lake Hamilton. Carpenter Dam was listed on the National Register of Historic Places on September 4, 1992, in recognition of its role in the growth and development of Hot Springs. Flavius Josephus (Flave) Carpenter, an associate of AP&L president Harvey Couch, selected the site for the construction of Carpenter Dam, ten miles upstream from Remmel Dam, and so …

Carps

In Arkansas, carps are an invasive (exotic or non-native) species whose introduction has caused economic and/or environmental damage. To date, there are five species of invasive carps that have entered or have been deliberately introduced into Arkansas for various reasons, and all belong to the order Cypriniformes and the minnow family Cyprinidae. Many of these fish originated from Asia or Europe, were introduced into North America, and pose a major threat to the ecology of native fishes, the environment, and the economy of fisheries in Arkansas. The longer it takes to respond to the damage done to an ecosystem done by these fish, the more money and time must be spent restoring and protecting that ecosystem. Grass Carp The grass …

Cave Crayfishes

aka: Troglobitic Crayfishes
Crayfishes belong to the Phylum Arthropoda, Subphylum Crustacea, Class Malacostraca, Order Decapoda, and Family Cambaridae. Crayfishes are a taxonomically diverse cosmopolitan group with more than 669 species worldwide. There appear to be two centers of geographic diversity, one in southeastern Australia (Southern Hemisphere center) and one in the southeastern United States (Northern Hemisphere center) in the southeastern Appalachian Mountains. Obligate cave-dwelling taxa in the United States occur in five main karst (limestone) geographic regions: (1) the Cumberland Plateau of the southern Appalachians of eastern Kentucky, eastern Tennessee, and northern Alabama; (2) the Interior Lowlands of southern Indiana, western Kentucky, and northwestern Tennessee; (3) the Greenbrier Valley of West Virginia; (4) the Ozark Plateau of southwestern Missouri, northern Arkansas, and eastern …

Cave Fishes

aka: Hypogean, Phreatic, Stygobitic, Subterranean, Troglomorphic, and Troglobitic Fishes
Cavefishes, found in fresh and brackish water, are adapted to living in caves and other subterranean habitats. There are more than 200 species of obligatory cavefishes found on all continents, except for Antarctica. New cavefish species continue to be described annually, and there are certainly undescribed species yet to be discovered. In terms of relative numbers of species on various continents, by far the greatest diversity is in Asia with more than 120 species, followed by South America with more than thirty species, and about thirty species in North America. In comparison, nine species are known from Africa, five from Oceania, and only a single species from Europe. China possesses the greatest diversity with more than eighty species, followed by …

Centipedes

Centipedes (class Chilopoda) are myriapods that include two subclasses, five living orders, and about 2,800 described species (out of an estimated worldwide fauna of approximately 8,000 species) within about twenty-three families. Their fossil history dates back over 410 million years ago to the late Silurian Period of the Paleozoic Era. In terms of worldwide geographic distribution, centipedes are found north of the Arctic Circle and inhabit all subarctic regions but are most abundant in temperate, desert, and tropical areas, where they are common terrestrial invertebrates. Humans have unintentionally introduced several species onto most oceanic islands. However, one order (Craterostigomorpha) is endemic to New Zealand and Tasmania. Members of the families Oryidae and Scutigeridae and of the subfamily Otostigminae have been …

Central Mudminnows

aka: Umbrids
The central mudminnow (Umbra limi) is a small (51 to 132 mm [2 to 5 in.]) fish that belongs to the Family Umbridae and Order Esociformes. There are three other North American members of the family: the eastern mudminnow (U. pygmaea) of the Eastern Seaboard and Atlantic Coastal Plain, the Alaska blackfish (Dallia pectoralis) that occurs in Alaska and adjacent Siberia, and the Olympic mudminnow (Novumbra hubbsi) of the Olympic Peninsula of Washington. All of these are strictly Northern Hemisphere freshwater species. A third Umbra species, the European Mudminnow (U. krameri), occurs widely throughout Europe. Mudminnows are most closely related to esocids (pikes and pickerels). The fossil record includes specimens that date back to the Oligocene of Eurasia and North …

Centrarchid Fishes

aka: Sunfishes
The Centrarchidae (sunfishes) are a family of North American native freshwater ray-finned fish belonging to the order Perciformes. There are eight genera and thirty-eight species in the family, thirty-four of which (eighty-nine percent) are extant. The group includes several game and pan fishes familiar to anglers, including smallmouth and largemouth basses, bluegills (“bream”), and crappies. The eight genera are: Acantharchus (mud sunfish), Ambloplites (rock basses), Archoplites (Sacramento perch), Centrarchus (flier), Enneacanthus (banded sunfishes), Lepomis (sunfishes), Micropterus (black basses), and Pomoxis (crappies). In Arkansas, there are five genera and twenty-two species of centrarchids, of which eighteen are native and four are introduced. The latter includes the rock bass (Ambloplites rupestris), redbreast sunfish (Lepomis auritus), redeye bass (Micropterus coosae), and shoal bass …

Cestodes

aka: Tapeworms
Cestodes (tapeworms) include flatworms belonging to the phylum Platyhelminthes, class Cestoidea, subclasses Cestodaria (two orders) and Eucestoda (sixteen orders), and about fifty-nine families. The subclass Cestodaria includes monozoic (unsegmented) tapeworms containing only a single set of male and female reproductive organs; these are parasitic in the intestinal tract and body cavity of fishes and turtles. The subclass Eucestoda is made up of polyzoic (segmented) or monozoic cestodes of varying structure and parasitic in the intestines of vertebrates. To date, there are more than 5,000 described species that, as endoparasites, infect all vertebrate classes. The classification of tapeworms remains ambiguous using classical morphological studies alone, and, although some studies have been done recently using molecular tools, further attention is needed to …

Chandler, Florence Clyde

Florence Clyde Chandler was a plant geneticist with a broad background in tree-breeding and the induction of polyploidy (the quality of having one or more extra sets of chromosomes) in flowering plants. Her exceptional success inducing polyploidy in the nuclei by using colchicines resulted in the production of a series of outstanding tetraploid and diploid verbenas. During World War II, she worked at the Guatemalan experimental station as a cinchona (a type of evergreen tree) breeder, where she furthered the successful development of a derivative for quinine, a malaria remedy. Born on September 28, 1901, in Oliver (Scott County) to William Festus Chandler and Nannie Charlotte Shannon, Florence Chandler was educated at the University of Arkansas (UA) in Fayetteville (Washington …

Chordate Parasites

aka: Parasitic Chordates
Although the majority of the world’s parasites are protists, helminths, invertebrates, and other miscellaneous groups of organisms, parasitism has also arisen within animals of the phylum Chordata (subphylum Vertebrata). All chordates, at some time in their development, possess five derived morphological characteristics as follows: (1) a dorsal tubular or hollow nerve cord, (2) a notochord, (3) pharyngeal gill slits or pouches, (4) an endostyle, and (5) a post-anal tail. Some examples of parasitic chordates are remoras (which attach to sharks and rays); the jawless fishes (lampreys and hagfishes), which prey upon other fishes; some birds that practice brood parasitism; and vampire bats. The Superclass Agnatha has both extinct groups and extant species, including the “jawless” fish (lamprey and hagfish) that …

Chowning, Frank Edwin

Frank Chowning was a longtime Little Rock (Pulaski County) attorney. He was also a plant enthusiast whose work with irises, especially his hybridization efforts, earned him an international reputation. Francis Edwin Chowning was born on May 26, 1894, in Rison (Cleveland County) to Nathaniel Barnett Chowning and Deborah Curtis Marks Chowning. Chowning grew up and received his early education in Rison before attending Henderson-Brown College (now Henderson State University) in Arkadelphia (Clark County). His time at Henderson-Brown was interrupted by World War I, during which Chowning served in the U.S. Army, earning the rank of lieutenant while stationed in France. Following the war, he earned his law degree from Vanderbilt University in 1922. He married Martha Speakes Bradford in 1928, …

Chytrid Fungus

Chytrid (pronounced “kit-rid”) fungus belongs to the Kingdom Fungi, Phylum Chytridiomycota, Class Chytridiomycetes, and Order Rhizophydiales, a division of zoosporic organisms. The fungus causes the disease chytridiomycosis, originally generated by Batrachochytrium dendrobatidis (Bd). An amphibian chytrid (discovered in 1998)—which causes an infection of the skin, with an affinity to frogs and toads—is present on every amphibian-inhabited continent. Further, broad lineage and genotypic variation have been found in B. dendrobatidis. The disease has resulted in a serious decline and extinction of more than 200 species of amphibians worldwide and poses the greatest threat to biodiversity of any known disease. By 2021, the fungus had pushed the regression of at least 501 amphibian species, or about one out of every 16 (6.3 …

Cladocerans

aka: Water Fleas
Water fleas (cladocerans) belong to the Phylum Arthropoda, Subphylum Crustacea, Class Branchiopoda, and Order Cladocera. Over 700 species and more than 100 genera have been recognized, but many additional species are surely undescribed. The genus Daphnia alone contains around 150 species. The order forms a monophyletic group, which is divided into four suborders and eleven families as follows: Anomopoda (five families), Ctenopoda (two families), Haplopoda (one family), and Onychopoda (three families). Although a complete survey of the cladocerans of Arkansas has not been given, about twenty species/taxa within five families have been reported. Cladocerans first appeared in the Permian. Until recently, the evolutionary history of cladocerans has been obscured by a mixture of erroneous fossil identifications and assumptions. However, knowledge …

Clegg, Moses Tran

Bacteriologist Moses Tran Clegg attracted international attention in 1909 when he reportedly became the first person to grow the leprosy bacillus in a laboratory. It was hoped that this breakthrough would lead to a vaccine to treat leprosy, also called Hansen’s disease, an infectious, disfiguring, and incurable disease caused by the bacillus Mycobacterium leprae. In addition to this achievement, Clegg also did research for the U.S. government on bubonic plague, amoebic dysentery, infantile paralysis, and cholera, and he coauthored scholarly bulletins on such bacteriological subjects as leprosy, amoebas, and parasitic protozoa. Born on September 1, 1876, in Red Bluff (Jefferson County) to Joseph T. Clegg, who was an allopathic doctor, and Ida Daugherty Clegg, Moses Clegg received his primary education …

Climate and Weather

Officially classified by climatologist Wladimir Köppen as having a humid sub-tropical climate, Arkansas is indeed humid, but numerous weather extremes run through the state. Humid sub-tropical is classified generally as a mild climate with a hot summer and no specific dry season. The Köppen classification is correct in that regard, but the state truly has four seasons, and they can all range from fairly mild to incredibly extreme. The topography of the land and its proximity to the plains to the west and the Gulf of Mexico to the south play a crucial role in its climate and weather. In the United States, warm, moist air travels into the plains from the Gulf of Mexico and interacts with cool, dry …

Climate Change

The spring of 2019 brought record flooding along the Arkansas River from Van Buren (Crawford County) to its confluence with the Mississippi River in the east. Historic crests occurred at Dardanelle (Yell County), Morrilton (Conway County), Toad Suck Lock and Dam near Conway (Faulkner County), and Pendleton (Desha County) between May 30 and June 6. In July 2019, the National Weather Service reported that the remnants of Hurricane Barry dumped 16.17 inches of rain on Dierks (Howard County), the most rain ever measured in a twenty-four-hour period (1:00 p.m. July 15 through 1:00 p.m. July 16) in Arkansas; the three-day total of 16.59 inches was the most rain associated with a tropical system in recorded state history. Murfreesboro (Pike County) …

Cnidarians

aka: Hydroids
aka: Corals
aka: Jellyfishes
aka: Sea Anemones
Cnidarians (hydroids, jellyfishes, corals, and sea anemones) form a diverse phylum (Cnidaria, old Phylum Coelenterata) that contains more than 10,000 species. The phylum also includes the parasitic Myxozoa. Typical cnidarians inhabit aquatic (predominantly marine) environments. Cnidarians are divided into two major groups: the Anthozoa (corals, sea anemones, and sea pens), which live as sessile polyps, and the subphylum Medusozoa (Hydra, jellyfishes, and sea wasps), many of which form a free-swimming medusa as well as polyps. There are five main classes: Anthozoa, Cubozoa, Hydrozoa, Scyphozoa, and Staurozoa. Only a few cnidarians can be found in Arkansas, including a jellyfish seen in lakes and rivers. In terms of evolutionary relationships, modern molecular phylogenetic results support the notion that anthozoans represent the first …

Coccidia

Coccidians are microorganisms belonging to the Phylum Apicomplexa and Suborder Eimeriorina, which includes eight to thirteen families, about 39 genera, and well over 2,000 species. These protists are intracellular (meaning they function inside the cell) parasites of medical and veterinary importance, including those in the genera Caryospora, Cryptosporidium, Cyclospora, Eimeria, Isospora, Sarcocystis, and Toxoplasma. Most are considered intestinal parasites that infect both invertebrates as well those animals in all vertebrate classes. These parasites cannot complete their life cycle without exploiting a host. Coccidiosis is a general term for the disease they can cause, and it is recognized as a major health concern in wild animal populations, domestic animals, and zoo animals. However, some infections appear not to cause any pathology …

Cockroaches

aka: Blattodea
Cockroaches belong to the Phylum Arthropoda, Subphylum Labiata, Superclass Hexapoda, Class Insecta, and Order Blattodea. The order includes approximately 4,600 species in almost 500 genera and seven families. Very likely at least twice this number remains to be discovered and described worldwide. Some of the most well-known cockroach examples are two pest species belonging to the family Blattidae: the American cockroach (Periplaneta americana) and German cockroach (Blattella germanica). Cockroaches are considered one of the most successful groups of invertebrates because of their adaptability in various environmental conditions and occupy a very wide range of habitats from caves to mountains to rainforests to deserts. As a group, cockroaches also exhibit a remarkable diversity of form, coloration, size, and behavior. Although no …

Collembollans

aka: Springtails
Springtails (collembolans) belong to the phylum Arthropoda and subphylum Hexapoda. They form the largest (about thirty-five families and 9,000 different species) of the three lineages of modern hexapods that are no longer considered to be included in the class Insecta (the other two are the proturan and dipluran apterygotes). Since each has internal mouthparts, the three are sometimes grouped together into a class called Entognatha. However, they do not appear to be any more closely related to one another than they all are to insects, which have external mouthparts. Indeed, they do share some features of insects, such as a body divided into three parts, a head with antennae, a three-segmented thorax, and each segment having a pair of jointed …

Cotter Bridge

aka: R. M. Ruthven Bridge
Completed in 1930, the R. M. Ruthven Bridge, originally named and often still called the Cotter Bridge, is located near Cotter (Baxter County) on the business route of U.S. Highway 62 and crosses the White River between Baxter and Marion counties. Recognizable for its Rainbow Arches, it was the first landmark in Arkansas to become a National Historic Civil Engineering Landmark and is one of only a small number of bridges designated as such. East-west travelers through northern Arkansas often encountered problems crossing the White River. Although ferries operated at several places along the river, the river had a tendency to flood rapidly, grounding the ferries and hindering traffic sometimes for several days. The fastest detour was to cross 100 …