North America is a continent within the Northern Hemisphere and all within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the west and south by the Pacific Ocean, to the southeast by South America and the Caribbean Sea. North America covers an area of about 24,709,000 square kilometers, about 16.5% of the earth's land area and about 4.8% of its total surface. North America is the third largest continent by area, following Asia and Africa, the fourth by population after Asia and Europe. In 2013, its population was estimated at nearly 579 million people in 23 independent states, or about 7.5% of the world's population, if nearby islands are included. North America was reached by its first human populations during the last glacial period, via crossing the Bering land bridge 40,000 to 17,000 years ago; the so-called Paleo-Indian period is taken to have lasted until about 10,000 years ago. The Classic stage spans the 6th to 13th centuries.
The Pre-Columbian era ended in 1492, the transatlantic migrations—the arrival of European settlers during the Age of Discovery and the Early Modern period. Present-day cultural and ethnic patterns reflect interactions between European colonists, indigenous peoples, African slaves and their descendants. Owing to the European colonization of the Americas, most North Americans speak English, Spanish or French, their culture reflects Western traditions; the Americas are accepted as having been named after the Italian explorer Amerigo Vespucci by the German cartographers Martin Waldseemüller and Matthias Ringmann. Vespucci, who explored South America between 1497 and 1502, was the first European to suggest that the Americas were not the East Indies, but a different landmass unknown by Europeans. In 1507, Waldseemüller produced a world map, in which he placed the word "America" on the continent of South America, in the middle of what is today Brazil, he explained the rationale for the name in the accompanying book Cosmographiae Introductio:... ab Americo inventore... quasi Americi terram sive Americam.
For Waldseemüller, no one should object to the naming of the land after its discoverer. He used the Latinized version of Vespucci's name, but in its feminine form "America", following the examples of "Europa", "Asia" and "Africa". Other mapmakers extended the name America to the northern continent, In 1538, Gerard Mercator used America on his map of the world for all the Western Hemisphere; some argue that because the convention is to use the surname for naming discoveries, the derivation from "Amerigo Vespucci" could be put in question. In 1874, Thomas Belt proposed a derivation from the Amerrique mountains of Central America. Marcou corresponded with Augustus Le Plongeon, who wrote: "The name AMERICA or AMERRIQUE in the Mayan language means, a country of perpetually strong wind, or the Land of the Wind, and... the can mean... a spirit that breathes, life itself." The United Nations formally recognizes "North America" as comprising three areas: Northern America, Central America, The Caribbean.
This has been formally defined by the UN Statistics Division. The term North America maintains various definitions in accordance with context. In Canadian English, North America refers to the land mass as a whole consisting of Mexico, the United States, Canada, although it is ambiguous which other countries are included, is defined by context. In the United States of America, usage of the term may refer only to Canada and the US, sometimes includes Greenland and Mexico, as well as offshore islands. In France, Portugal, Romania and the countries of Latin America, the cognates of North America designate a subcontinent of the Americas comprising Canada, the United States, Mexico, Greenland, Saint Pierre et Miquelon, Bermuda. North America has been referred to by other names. Spanish North America was referred to as Northern America, this was the first official name given to Mexico. Geographically the North American continent has many subregions; these include cultural and geographic regions. Economic regions included those formed by trade blocs, such as the North American Trade Agreement bloc and Central American Trade Agreement.
Linguistically and culturally, the continent could be divided into Latin America. Anglo-America includes most of Northern America and Caribbean islands with English-speaking populations; the southern North American continent is composed of two regions. These are the Caribbean; the north of the continent maintains recognized regions as well. In contrast to the common definition of "North America", which encompasses the whole continent, the term "North America" is sometimes used to refer only to Mexico, the United States, Greenland; the term Northern America refers to the northern-most countries and territories of North America: the United States, Bermuda, St. Pierre and Miquelon and Greenland. Although the term does not refer to a unifie
South Carolina is a state in the Southeastern United States and the easternmost of the Deep South. It is bordered to the north by North Carolina, to the southeast by the Atlantic Ocean, to the southwest by Georgia across the Savannah River. South Carolina became the eighth state to ratify the U. S. Constitution on May 23, 1788. South Carolina became the first state to vote in favor of secession from the Union on December 20, 1860. After the American Civil War, it was readmitted into the United States on June 25, 1868. South Carolina is the 40th most extensive and 23rd most populous U. S. state. Its GDP as of 2013 was $183.6 billion, with an annual growth rate of 3.13%. South Carolina is composed of 46 counties; the capital is Columbia with a 2017 population of 133,114. The Greenville-Anderson-Mauldin metropolitan area is the largest in the state, with a 2017 population estimate of 895,923. South Carolina is named in honor of King Charles I of England, who first formed the English colony, with Carolus being Latin for "Charles".
South Carolina is known for its 187 miles of coastline, beautiful lush gardens, historic sites and Southern plantations, colonial and European cultures, its growing economic development. The state can be divided into three geographic areas. From east to west: the Atlantic coastal plain, the Piedmont, the Blue Ridge Mountains. Locally, the coastal plain is referred to the other two regions as Upstate; the Atlantic Coastal Plain makes up two-thirds of the state. Its eastern border is a chain of tidal and barrier islands; the border between the low country and the up country is defined by the Atlantic Seaboard fall line, which marks the limit of navigable rivers. The state's coastline contains many salt marshes and estuaries, as well as natural ports such as Georgetown and Charleston. An unusual feature of the coastal plain is a large number of Carolina bays, the origins of which are uncertain; the bays tend to be oval. The terrain is flat and the soil is composed of recent sediments such as sand and clay.
Areas with better drainage make excellent farmland. The natural areas of the coastal plain are part of the Middle Atlantic coastal forests ecoregion. Just west of the coastal plain is the Sandhills region; the Sandhills are remnants of coastal dunes from a time when the land was sunken or the oceans were higher. The Upstate region contains the roots of an eroded mountain chain, it is hilly, with thin, stony clay soils, contains few areas suitable for farming. Much of the Piedmont was once farmed. Due to the changing economics of farming, much of the land is now reforested in Loblolly pine for the lumber industry; these forests are part of the Southeastern mixed forests ecoregion. At the southeastern edge of the Piedmont is the fall line, where rivers drop to the coastal plain; the fall line was an important early source of water power. Mills built to harness this resource encouraged the growth of several cities, including the capital, Columbia; the larger rivers are navigable up to the fall line. The northwestern part of the Piedmont is known as the Foothills.
The Cherokee Parkway is a scenic driving route through this area. This is. Highest in elevation is the Blue Ridge Region, containing an escarpment of the Blue Ridge Mountains, which continue into North Carolina and Georgia, as part of the southern Appalachian Mountains. Sassafras Mountain, South Carolina's highest point at 3,560 feet, is in this area. In this area is Caesars Head State Park; the environment here is that of the Appalachian-Blue Ridge forests ecoregion. The Chattooga River, on the border between South Carolina and Georgia, is a favorite whitewater rafting destination. South Carolina has several major lakes covering over 683 square miles. All major lakes in South Carolina are man-made; the following are the lakes listed by size. Lake Marion 110,000 acres Lake Strom Thurmond 71,100 acres Lake Moultrie 60,000 acres Lake Hartwell 56,000 acres Lake Murray 50,000 acres Russell Lake 26,650 acres Lake Keowee 18,372 acres Lake Wylie 13,400 acres Lake Wateree 13,250 acres Lake Greenwood 11,400 acres Lake Jocassee 7,500 acres Lake Bowen Earthquakes in South Carolina demonstrate the greatest frequency along the central coastline of the state, in the Charleston area.
South Carolina averages 10–15 earthquakes a year below magnitude 3. The Charleston Earthquake of 1886 was the largest quake to hit the Southeastern United States; this 7.2 magnitude earthquake destroyed much of the city. Faults in this region are difficult to study at the surface due to thick sedimentation on top of them. Many of the ancient faults are within plates rather than along plate boundaries. South Carolina has a humid subtropical climate, although high-elevation areas in the Upstate area have fewer subtropical characteristics than areas on the Atlantic coastline. In the summer, South Carolina is hot and humid, with daytime temperatures averaging between 86–93 °F in most of the state and overnight lows averaging 70–75 °F on the coast and from 66–73 °F inland. Winter temperatures are much less uniform in South Carolina. Coastal areas of the state have mild winters, with high temperatures approaching an average of 60 °F and overnight lows around 40 °F. Inland, the average January overnight low is around 32 °F i
A chordate is an animal constituting the phylum Chordata. During some period of their life cycle, chordates possess a notochord, a dorsal nerve cord, pharyngeal slits, an endostyle, a post-anal tail: these five anatomical features define this phylum. Chordates are bilaterally symmetric; the Chordata and Ambulacraria together form the superphylum Deuterostomia. Chordates are divided into three subphyla: Vertebrata. There are extinct taxa such as the Vetulicolia. Hemichordata has been presented as a fourth chordate subphylum, but now is treated as a separate phylum: hemichordates and Echinodermata form the Ambulacraria, the sister phylum of the Chordates. Of the more than 65,000 living species of chordates, about half are bony fish that are members of the superclass Osteichthyes. Chordate fossils have been found from as early as the Cambrian explosion, 541 million years ago. Cladistically, vertebrates - chordates with the notochord replaced by a vertebral column during development - are considered to be a subgroup of the clade Craniata, which consists of chordates with a skull.
The Craniata and Tunicata compose the clade Olfactores. Chordates form a phylum of animals that are defined by having at some stage in their lives all of the following anatomical features: A notochord, a stiff rod of cartilage that extends along the inside of the body. Among the vertebrate sub-group of chordates the notochord develops into the spine, in wholly aquatic species this helps the animal to swim by flexing its tail. A dorsal neural tube. In fish and other vertebrates, this develops into the spinal cord, the main communications trunk of the nervous system. Pharyngeal slits; the pharynx is the part of the throat behind the mouth. In fish, the slits are modified to form gills, but in some other chordates they are part of a filter-feeding system that extracts particles of food from the water in which the animals live. Post-anal tail. A muscular tail that extends backwards behind the anus. An endostyle; this is a groove in the ventral wall of the pharynx. In filter-feeding species it produces mucus to gather food particles, which helps in transporting food to the esophagus.
It stores iodine, may be a precursor of the vertebrate thyroid gland. There are soft constraints that separate chordates from certain other biological lineages, but are not part of the formal definition: All chordates are deuterostomes; this means. All chordates are based on a bilateral body plan. All chordates are coelomates, have a fluid filled body cavity called a coelom with a complete lining called peritoneum derived from mesoderm; the following schema is from the third edition of Vertebrate Palaeontology. The invertebrate chordate classes are from Fishes of the World. While it is structured so as to reflect evolutionary relationships, it retains the traditional ranks used in Linnaean taxonomy. Phylum Chordata †Vetulicolia? Subphylum Cephalochordata – Class Leptocardii Clade Olfactores Subphylum Tunicata – Class Ascidiacea Class Thaliacea Class Appendicularia Class Sorberacea Subphylum Vertebrata Infraphylum incertae sedis Cyclostomata Superclass'Agnatha' paraphyletic Class Myxini Class Petromyzontida or Hyperoartia Class †Conodonta Class †Myllokunmingiida Class †Pteraspidomorphi Class †Thelodonti Class †Anaspida Class †Cephalaspidomorphi Infraphylum Gnathostomata Class †Placodermi Class Chondrichthyes Class †Acanthodii Superclass Osteichthyes Class Actinopterygii Class Sarcopterygii Superclass Tetrapoda Class Amphibia Class Sauropsida Class Synapsida Craniates, one of the three subdivisions of chordates, all have distinct skulls.
They include the hagfish. Michael J. Benton commented that "craniates are characterized by their heads, just as chordates, or all deuterostomes, are by their tails". Most craniates are vertebrates; these consist of a series of bony or cartilaginous cylindrical vertebrae with neural arches that protect the spinal cord, with projections that link the vertebrae. However hagfish have incomplete braincases and no vertebrae, are therefore not regarded as vertebrates, but as members of the craniates, the group from which vertebrates are thought to have evolved; however the cladistic exclusion of hagfish from the vertebrates is controversial, as they ma
The Ohio River is a 981-mile long river in the midwestern United States that flows southwesterly from western Pennsylvania south of Lake Erie to its mouth on the Mississippi River at the southern tip of Illinois. It is the second largest river by discharge volume in the United States and the largest tributary by volume of the north-south flowing Mississippi River that divides the eastern from western United States; the river flows through or along the border of six states, its drainage basin includes parts of 15 states. Through its largest tributary, the Tennessee River, the basin includes several states of the southeastern U. S, it is the source of drinking water for three million people. The lower Ohio River just below Louisville is obstructed by rapids known as the Falls of the Ohio where the water level falls 26ft. in 2 miles and is impassible for navigation. The McAlpine Locks and Dam, a shipping canal bypassing the rapids, now allows commercial navigation from the Forks of the Ohio at Pittsburgh to the Port of New Orleans at the mouth of the Mississippi on the Gulf of Mexico.
The name "Ohio" comes from the Ohi: yo', lit. "Good River". Discovery of the Ohio River may be attributed to English explorers from Virginia in the latter half of the 17th century. In his Notes on the State of Virginia published in 1781–82, Thomas Jefferson stated: "The Ohio is the most beautiful river on earth, its current gentle, waters clear, bosom smooth and unbroken by rocks and rapids, a single instance only excepted." In the late 18th century, the river was the southern boundary of the Northwest Territory. It became a primary transportation route for pioneers during the westward expansion of the early U. S; the river is sometimes considered as the western extension of the Mason–Dixon Line that divided Pennsylvania from Maryland, thus part of the border between free and slave territory, between the Northern and Southern United States or Upper South. Where the river was narrow, it was the way to freedom for thousands of slaves escaping to the North, many helped by free blacks and whites of the Underground Railroad resistance movement.
The Ohio River is a climatic transition area, as its water runs along the periphery of the humid subtropical and humid continental climate areas. It is inhabited by flora of both climates. In winter, it freezes over at Pittsburgh but farther south toward Cincinnati and Louisville. At Paducah, Kentucky, in the south, near the Ohio's confluence with the Mississippi, it is ice-free year-round; the name "Ohio" comes from the Seneca language, Ohi:yo', a proper name derived from ohiːyoːh, therefore translating to "Good River". "Great river" and "large creek" have been given as translations. Native Americans, including the Lenni Lenape and Iroquois, considered the Ohio and Allegheny rivers as the same, as is suggested by a New York State road sign on Interstate 86 that refers to the Allegheny River as Ohi:yo'. An earlier Miami-Illinois language name was applied to the Ohio River, Mosopeleacipi. Shortened in the Shawnee language to pelewa thiipi, spelewathiipi or peleewa thiipiiki, the name evolved through variant forms such as "Polesipi", "Peleson", "Pele Sipi" and "Pere Sipi", stabilized to the variant spellings "Pelisipi", "Pelisippi" and "Pellissippi".
Applied just to the Ohio River, the "Pelisipi" name was variously applied back and forth between the Ohio River and the Clinch River in Virginia and Tennessee. In his original draft of the Land Ordinance of 1784, Thomas Jefferson proposed a new state called "Pelisipia", to the south of the Ohio River, which would have included parts of present-day Eastern Kentucky and West Virginia; the river had great significance in the history of the Native Americans, as numerous civilizations formed along its valley. For thousands of years, Native Americans used the river as a major trading route, its waters connected communities. In the five centuries before European conquest, the Mississippian culture built numerous regional chiefdoms and major earthwork mounds in the Ohio Valley, such as Angel Mounds near Evansville, Indiana, as well as in the Mississippi Valley and the Southeast; the Osage, Omaha and Kaw lived in the Ohio Valley, but under pressure from the Iroquois to the northeast, migrated west of the Mississippi River in the 17th century to territory now defined as Missouri and Oklahoma.
The discovery and traversal of the Ohio River by Europeans admits of several possibilities, all in the latter half of the 17th century. Virginian Englishman Abraham Wood's trans-Appalachian expeditions between 1654 and 1664; the first person to traverse the length of the river, from the headwaters of the Allegheny to its mouth on the Mississippi, was a Dutch trader from New York, Arnout Viele, in 1692. In 1749, Great Britain established the Ohio Company to trade in the area. Exploration of the territory and trade with the Indians in the region near the Forks brought British colonials from both Pennsylvania and Virginia across the mountains, both colonies claimed the territory; the movement across the Allegheny Mountains of British settlers and the claims of the area near modern day Pittsburgh led to conflict with the French, who had forts in the Ohio River Valley. This conflict was called the Indian War. In 17
The channel catfish is North America's most numerous catfish species. It is the official fish of Kansas, Iowa and Tennessee, is informally referred to as a "channel cat". In the United States, they are the most fished catfish species with around 8 million anglers targeting them per year; the popularity of channel catfish for food has contributed to the rapid expansion of aquaculture of this species in the United States. Channel catfish are native to the Nearctic, being well distributed in lower Canada and the eastern and northern United States, as well as parts of northern Mexico, they have been introduced into some waters of landlocked Europe and parts of Malaysia and as many parts of Indonesia. They thrive in small and large rivers, natural lakes, ponds. Channel "cats" are cavity nesters, meaning they lay their eggs in crevices, hollows, or debris, to protect them from swift currents. In Canada, the species is though not limited to the Great Lakes watershed from Lake Nipigon southward. Channel catfish possess keen senses of smell and taste.
At the pits of their nostrils are sensitive odor-sensing organs with a high concentration of olfactory receptors. In channel catfish, these organs are sensitive enough to detect several amino acids at about one part per 100 million in water. In addition, the channel catfish has taste buds distributed over the surface of its entire body; these buds are concentrated on the fish's four pair of barbels surrounding the mouth — about 25 buds per square millimeter. This combination of exceptional senses of taste and smell allows the channel catfish to find food in dark, stained, or muddy water with relative ease, they possess a Weberian apparatus, which amplifies sound waves that would otherwise not be perceivable. A member of the American catfish genus Ictalurus, channel catfish have a top-end size of about 40–50 pounds; the world record channel catfish weighed 58 pounds, was taken from the Santee-Cooper Reservoir in South Carolina, on July 7, 1964. Realistically, a channel catfish over 20 lb is a spectacular specimen, most catfish anglers view a 10-lb fish as a admirable catch.
Furthermore, the average size channel catfish an angler could expect to find in most waterways would be between 2 and 4 pounds. Channel catfish coexist in the same waterways with its close relative, the blue catfish, somewhat less common, but tends to grow much larger; as channel catfish grow longer, they increase in weight. The relationship between length and weight is not linear; the relationship between length and weight for nearly all species of fish can be expressed by an equation of the form: W = b Invariably, b is close to 3.0 for all species, L 1 is the length of a typical fish weighing 1 kg. For channel catfish, b = 3.2293, somewhat higher than for many common species, L 1 = 45.23 cm. Catfish have enhanced capabilities of taste perception, hence called the “swimming tongue”, due to the presence of taste buds all over the external body surface and inside the oropharyngeal cavity, they have high sensitivity to amino acids, which explains their unique communication methods as follows. The catfish has a facial taste system, responsive to L-alanine and L-arginine.
More their facial taste system senses heightened levels of L-amino acids in freshwater. Feeding behavior to food is due to amino acids released by food; this is reported to cause maxillary and mandibular barbell movements, which orient the catfish’s posture and food search. When the food stimulates the taste receptors, it causes more excitation which see as exaggerated biting, turning, or mastication; the channel catfish is adapted to limited light conditions. Members of the genus Ictalurus, which inhabit muddy waters, do not depend on visual cues. Instead, they are known to rely on chemotaxic cues. Sound production may be another important means of communication among channel catfish and other species living in turbid habitats; the North American channel catfish is an ostariophysan, or a bony fish occupying a freshwater habitat. These fishes are known to produce club cells and alarm substances for communication purposes. Both the fish’s habitat and the presence of chemosensory cells covering the body are the results of favored selection for this method of communication.
Catfishes are capable of recognizing individual specific pheromones. Through these pheromones, a catfish can identify not only the species and sex of a conspecific, but its age, reproductive state, or hierarchical social status. Territoriality in channel catfish is identifiable by a change in body odor, recognizable by other members of the same species; this chemical change in the amino-acid composition of the skin mucus can be noted by chromatographic methods, are not long-lasting. Changes may be the result of the release of the contents of the club cells; these cells do not open directly to the surface of the skin, but injury caused by fighting and other agonistic behaviors may release the cells’ contents. Since catfish have a dominance hierarchy system, information relative to the change of status of any fish is important in recognition of the social strata. In the channe
The striped bass called Atlantic striped bass, linesider, rock or rockfish, is an anadromous Perciforme fish of the family Moronidae found along the Atlantic coast of North America. It has been introduced into inland recreational fisheries across the United States. Striped bass found in the Gulf of Mexico are a separate strain referred to as Gulf Coast striped bass; the striped bass is the state fish of Maryland, Rhode Island, South Carolina, the state saltwater fish of New York, New Jersey and New Hampshire. The history of the striped bass fishery in North America dates back to the Colonial period. Many written accounts by some of the first European settlers describe the immense abundance of striped bass, along with alewives and spawning up most rivers in the coastal Northeast; the striped bass is a typical member of the Moronidae family in shape, having a streamlined, silvery body marked with longitudinal dark stripes running from behind the gills to the base of the tail. Common mature size is 20 to 40 pounds.
The largest specimen recorded was 124 pounds, netted in 1896. Striped bass are believed to live for up to 30 years; the maximum weight can be north of eighty pounds. The average size in length is twenty to thirty five inches and five to just shy of twenty pounds. Striped bass are native to the Atlantic coastline of North America from the St. Lawrence River into the Gulf of Mexico to Louisiana, they are anadromous fish that migrate between salt water. Spawning takes place in fresh water. Striped bass have been introduced to the Pacific Coast of North America and into many of the large reservoir impoundments across the United States by state game and fish commissions for the purposes of recreational fishing and as a predator to control populations of gizzard shad; these include: Elephant Butte Lake in New Mexico. Striped bass have been introduced into waters in Ecuador, Latvia, Russia, South Africa, Turkey for sport fishing and aquaculture; the spawning success of striped bass has been studied in the San Francisco Bay-Delta water system, with a finding that high total dissolved solids reduce spawning.
At levels as low as 200 mg/l TDS, an observable diminution of spawning productivity occurs. They can be found in lakes, ponds and wetlands. Though the population of striped bass was growing and repopulating in the late 1980s and throughout the 1990s, a study executed by the Wildlife and Fisheries Program at West Virginia University found that the rapid growth of the striped bass population was exerting a tremendous pressure on its prey; this pressure on their food source was putting their own population at risk due to the population of prey not coming back to the same spawning areas. In the United States, the striped bass was designated as a protected game fish in 2007, executive agencies were directed to use existing legal authorities to prohibit the sale of striped bass caught in federal waters in the Atlantic Ocean and Gulf of Mexico. In Canada, the province of Quebec designated the striped bass population of the Saint Lawrence as extirpated in 1996. Analysis of available data implicated dredging in the disappearance.
In 2002, a reintroduction program was successful. Striped bass spawn in fresh water, although they have been adapted to freshwater habitat, they spend their adult lives in saltwater. Four important bodies of water with breeding stocks of striped bass are: Chesapeake Bay, Massachusetts Bay/Cape Cod, Hudson River, Delaware River. Many of the rivers and tributaries that emptied into the Atlantic, had at one time, bred stock of striped bass; this occurred until the 1860s. One of the largest breeding areas is the Chesapeake Bay, where populations from Chesapeake and Delaware bays have intermingled; the few successful spawning populations of freshwater striped bass include Lake Texoma, Lake Weiss, the Colorado River and its reservoirs downstream from and including Lake Powell, the Arkansas River, as well as Lake Marion that retained a landlocked breeding population when the dam was built. Stocking of striped bass was discontinued at Lake Mead in 1973 once natural reproduction was verified. Striped bass have been hybridized with white bass to produce hybrid striped bass known as wiper, whiterock bass, sunshine bass, palmetto bass, Cherokee bass.
These hybrids have been stocked in many freshwater areas across the US. Striped bass are of significant value for sport fishing, have been introduced to many waterways outside their natural range. A variety of angling methods are used, including trolling and surf casting with topwater lures a good pick for surf casting, as well as bait casting with live and dead bait. Striped bass will take a number of live and fresh baits, includ
Predation is a biological interaction where one organism, the predator and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation and parasitoidism, it is distinct from scavenging on dead prey, though many predators scavenge. Predators may search for prey or sit and wait for it; when prey is detected, the predator assesses. This may involve pursuit predation, sometimes after stalking the prey. If the attack is successful, the predator kills the prey, removes any inedible parts like the shell or spines, eats it. Predators are adapted and highly specialized for hunting, with acute senses such as vision, hearing, or smell. Many predatory animals, both vertebrate and invertebrate, have sharp claws or jaws to grip and cut up their prey. Other adaptations include aggressive mimicry that improve hunting efficiency. Predation has a powerful selective effect on prey, the prey develop antipredator adaptations such as warning coloration, alarm calls and other signals, mimicry of well-defended species, defensive spines and chemicals.
Sometimes predator and prey find themselves in an evolutionary arms race, a cycle of adaptations and counter-adaptations. Predation has been a major driver of evolution since at least the Cambrian period. At the most basic level, predators eat other organisms. However, the concept of predation is broad, defined differently in different contexts, includes a wide variety of feeding methods. A parasitoid, such as an ichneumon wasp, lays its eggs on its host. Zoologists call this a form of parasitism, though conventionally parasites are thought not to kill their hosts. A predator can be defined to differ from a parasitoid in two ways: it kills its prey immediately. There are other borderline cases. Micropredators are small animals that, like predators, feed on other organisms. However, since they do not kill their hosts, they are now thought of as parasites. Animals that graze on phytoplankton or mats of microbes are predators, as they consume and kill their food organisms. However, when animals eat seeds or eggs, they are consuming entire living organisms, which by definition makes them predators, albeit unconventional ones: for instance, a mouse that eats grass seeds has no adaptations for tracking and subduing prey and its teeth are not adapted to slicing through flesh.
Scavengers, organisms that only eat organisms found dead, are not predators, but many predators such as the jackal and the hyena scavenge when the opportunity arises. Among invertebrates, social wasps are both scavengers of other insects. While examples of predators among mammals and birds are well known, predators can be found in a broad range of taxa, they are common among insects, including mantids, dragonflies and scorpionflies. In some species such as the alderfly, only the larvae are predatory. Spiders are predatory, as well as other terrestrial invertebrates such as scorpions. In marine environments, most cnidarians, ctenophora and flatworms are predatory. Among crustaceans, crabs and barnacles are predators, in turn crustaceans are preyed on by nearly all cephalopods. Seed predation is restricted to mammals and insects and is found in all terrestrial ecosystems. Egg predation includes both specialist egg predators such as some colubrid snakes and generalists such as foxes and badgers that opportunistically take eggs when they find them.
Some plants, like the pitcher plant, the Venus fly trap and the sundew, are carnivorous and consume insects. Some carnivorous fungi catch nematodes using either active traps in the form of constricting rings, or passive traps with adhesive structures. Many species of protozoa and bacteria prey on other microorganisms. Among freshwater and marine zooplankton, whether single-celled or multi-cellular, predatory grazing on phytoplankton and smaller zooplankton is common, found in many species of nanoflagellates, ciliates, rotifers, a diverse range of meroplankton animal larvae, two groups of crustaceans, namely copepods and cladocerans. To feed, a predator must search for and kill its prey; these actions form a foraging cycle. The predator must decide. If it chooses pursuit, its physical capabilities determine the mode of pursuit. Having captured the prey, it may need to expend energy handling it (e.g. killing it, removing any shell or