The Overseas Highway is a 113-mile highway carrying U. S. Route 1 through the Florida Keys. Large parts of it were built on the former right-of-way of the Overseas Railroad, the Key West Extension of the Florida East Coast Railway. Completed in 1912, the Overseas Railroad was damaged and destroyed in the 1935 Labor Day hurricane; the Florida East Coast Railway was financially unable to rebuild the destroyed sections, so the roadbed and remaining bridges were sold to the state of Florida for $640,000. Since the 1950s the Overseas Highway has been refurbished into a main coastal highway between the cities of Miami and Key West, offering travelers an exotic roadway through a tropical savanna environment and access to the largest area of coral reefs on the U. S. mainland. Many exotic animals such as the American Alligator, American Crocodile and Key Deer inhabit the tropical islands of the Florida Keys. While the Overseas Highway today runs along the former Overseas Railroad right of way, portions of the highway came into existence earlier in a different alignment while the railroad was still operational.
The concept of an Overseas Highway began with the Miami Motor Club in 1921. The Florida land boom of the 1920s was underway and the club wanted to attract tourists to reached fishing areas, which could only be reached by boat or train at the time; the land boom attracted real estate interests who sought vehicular access to the upper keys where there were thousands of acres of undeveloped land. The completion of the railroad further proved. Construction on the original Overseas Highway, designated State Road 4A, lasted through most of the mid 1920s. Opening for traffic on January 25, 1928, the original highway existed in two segments at its greatest extent. One segment ran from the mainland via Card Sound Road to Key Largo and extended as far as Lower Matecumbe Key, while a segment in the lower keys existed from No Name Key to Key West. An automobile ferry service connected the 41 mile gap between No Name Keys. State Road 4A ran alongside of the Overseas Railroad in the upper keys but in the lower keys, it followed a much different path than the railroad and current highway.
The ferry landing on No Name Key was located at the end of what is now Watson Boulevard, which carried State Road 4A across No Name Key and Big Pine Key before it crossed to Little Torch Key. On Little Torch Key, it rejoined the railroad, it would continue along the north side of the railroad to Upper Sugarloaf Key, where it turned south and ran along the current route of County Roads 939 and 939A over Lower Sugarloaf Key and the Saddlebunch Keys. From the Saddlebunch Keys, State Road 4A crossed onto Geiger Key, continuing along what is now Geiger Road and Boca Chica Road. On Boca Chica Key, it followed the shoreline south of Naval Air Station Key West's airstrip to Boca Chica Beach before crossing to Stock Island. On Stock Island, it followed Maloney Avenue and MacDonald Avenue where it rejoined the Overseas Railroad heading into Key West. Most of the State Road 4A bridges in the Lower Keys were of wooden construction and had been in use by the early 1920s. By the early 1930s it was clear that the ferries were insufficient for the travel needs of the keys, Monroe County and the State Road Department began making plans to connect the two portions of State Road 4A to make a continuous highway.
By 1931, the ferries would service a 13-mile road built through Marathon on the Vaca Keys with terminals at Hog and Grassy Keys. In 1933, the state legislature created the Overseas Road and Toll Bridge District to seek federal funding to extend the roadways. Funding was scarce as the country was in the midst of the Great Depression, but funding would come through the Federal Emergency Relief Administration, part of President Franklin D. Roosevelt's New Deal. Hundreds of disgruntled World War I veterans seeking early payment of wartime bonuses were employed for construction on the roadway and bridges as part of a government relief program. Construction on a bridge connecting Lower Matecumbe Key and Long Key was underway when the Category 5 Labor Day Hurricane struck Islamorada on September 2, 1935; the hurricane caused widespread damage throughout the area and destroyed much of the Overseas Railroad in the upper keys. Of the over 400 fatalities from the hurricane, more than half were their families.
Their deaths caused anger and charges of mismanagement. Just west of Lower Matecumbe Key at Mile Marker 73 on the current highway, eight concrete bridge piers and a small dredged island are all that remains of the veterans' work; the dredged island is now known as Veteran's Key and the piers remain as a tribute to the veterans with a memorial plaque on Craig Key. After the hurricane, the Florida East Coast Railway was financially unable to rebuild the damaged sections of the Overseas Railroad. Seizing a rare opportunity, the state purchased the railroad's entire right of way and remaining infrastructure for a price of $640,000; the Overseas Road and Toll Bridge District abandoned its original highway plans and made new plans to build the highway on the old rail bed from Lower Matecumbe Key to Little Torch Key connecting the two segments of State Road 4A. The railroad's bridges, which withstood the hurricane and were in good condition, were retrofitted with new two-lane wide concrete surfaces for automobile use.
In the case of the Bahia Honda Rail Bridge, a truss bridge, the concrete road surface was built on top of the trusses. The conversion of the railroad bridges to automobile use was accomplished by Cleary B
Fishing is the activity of trying to catch fish. Fish are caught in the wild. Techniques for catching fish include hand gathering, netting and trapping. “Fishing” may include catching aquatic animals other than fish, such as molluscs, cephalopods and echinoderms. The term is not applied to catching farmed fish, or to aquatic mammals, such as whales where the term whaling is more appropriate. In addition to being caught to be eaten, fish are caught as recreational pastimes. Fishing tournaments are held, caught fish are sometimes kept as preserved or living trophies; when bioblitzes occur, fish are caught and released. According to the United Nations FAO statistics, the total number of commercial fishermen and fish farmers is estimated to be 38 million. Fisheries and aquaculture provide direct and indirect employment to over 500 million people in developing countries. In 2005, the worldwide per capita consumption of fish captured from wild fisheries was 14.4 kilograms, with an additional 7.4 kilograms harvested from fish farms.
Fishing is an ancient practice that dates back to at least the beginning of the Upper Paleolithic period about 40,000 years ago. Isotopic analysis of the skeletal remains of Tianyuan man, a 40,000-year-old modern human from eastern Asia, has shown that he consumed freshwater fish. Archaeology features such as shell middens, discarded fish bones, cave paintings show that sea foods were important for survival and consumed in significant quantities. Fishing in Africa is evident early on in human history. Neanderthals were fishing by about 200,000 BC to have a source of food for their families and to trade or sell. People could have developed basketry for fish traps, spinning and early forms of knitting in order to make fishing nets to be able to catch more fish in larger quantities. During this period, most people lived a hunter-gatherer lifestyle and were, of necessity on the move. However, where there are early examples of permanent settlements such as those at Lepenski Vir, they are always associated with fishing as a major source of food.
The British dogger was an early type of sailing trawler from the 17th century, but the modern fishing trawler was developed in the 19th century, at the English fishing port of Brixham. By the early 19th century, the fishermen at Brixham needed to expand their fishing area further than before due to the ongoing depletion of stocks, occurring in the overfished waters of South Devon; the Brixham trawler that evolved there was of a sleek build and had a tall gaff rig, which gave the vessel sufficient speed to make long distance trips out to the fishing grounds in the ocean. They were sufficiently robust to be able to tow large trawls in deep water; the great trawling fleet that built up at Brixham, earned the village the title of'Mother of Deep-Sea Fisheries'. This revolutionary design made large scale trawling in the ocean possible for the first time, resulting in a massive migration of fishermen from the ports in the South of England, to villages further north, such as Scarborough, Grimsby and Yarmouth, that were points of access to the large fishing grounds in the Atlantic Ocean.
The small village of Grimsby grew to become the largest fishing port in the world by the mid 19th century. An Act of Parliament was first obtained in 1796, which authorised the construction of new quays and dredging of the Haven to make it deeper, it was only in the 1846, with the tremendous expansion in the fishing industry, that the Grimsby Dock Company was formed. The foundation stone for the Royal Dock was laid by Albert the Prince consort in 1849; the dock covered 25 acres and was formally opened by Queen Victoria in 1854 as the first modern fishing port. The elegant Brixham trawler spread across the world. By the end of the 19th century, there were over 3,000 fishing trawlers in commission in Britain, with 1,000 at Grimsby; these trawlers were sold to fishermen including from the Netherlands and Scandinavia. Twelve trawlers went on to form the nucleus of the German fishing fleet; the earliest steam powered fishing boats first appeared in the 1870s and used the trawl system of fishing as well as lines and drift nets.
These were large boats 80–90 feet in length with a beam of around 20 feet. They travelled at 9 -- 11 knots; the earliest purpose built fishing vessels were designed and made by David Allan in Leith, Scotland in March 1875, when he converted a drifter to steam power. In 1877, he built. Steam trawlers were introduced at Hull in the 1880s. In 1890 it was estimated; the steam drifter was not used in the herring fishery until 1897. The last sailing fishing trawler was built in 1925 in Grimsby. Trawler designs adapted as the way they were powered changed from sail to coal-fired steam by World War I to diesel and turbines by the end of World War II. In 1931, the first powered drum was created by Laurie Jarelainen; the drum was a circular device, set to the side of the boat and would draw in the nets. Since World War II, radio navigation aids and fish finders have been used; the first trawlers fished over the side, rather than over the stern. The first purpose built stern trawler was Fairtry built in 1953 at Scotland.
The ship was much larger than any other trawlers in operation and inaugurated the era of the'super trawler'. As the ship pulled its nets over the stern, it could lift out a much greater haul of up to 60 tons; the ship served as a basis for the expansion of'su
A lagoon is a shallow body of water separated from a larger body of water by barrier islands or reefs. Lagoons are divided into coastal lagoons and atoll lagoons, they have been identified as occurring on mixed-sand and gravel coastlines. There is an overlap between bodies of water classified as coastal lagoons and bodies of water classified as estuaries. Lagoons are common coastal features around many parts of the world. Lagoons are shallow elongated bodies of water separated from a larger body of water by a shallow or exposed shoal, coral reef, or similar feature; some authorities include fresh water bodies in the definition of "lagoon", while others explicitly restrict "lagoon" to bodies of water with some degree of salinity. The distinction between "lagoon" and "estuary" varies between authorities. Richard A. Davis Jr. restricts "lagoon" to bodies of water with little or no fresh water inflow, little or no tidal flow, calls any bay that receives a regular flow of fresh water an "estuary". Davis does state that the terms "lagoon" and "estuary" are "often loosely applied in scientific literature."
Timothy M. Kusky characterizes lagoons as being elongated parallel to the coast, while estuaries are drowned river valleys, elongated perpendicular to the coast; when used within the context of a distinctive portion of coral reef ecosystems, the term "lagoon" is synonymous with the term "back reef" or "backreef", more used by coral reef scientists to refer to the same area. Coastal lagoons are classified as inland bodies of water. Many lagoons do not include "lagoon" in their common names. Albemarle and Pamlico sounds in North Carolina, Great South Bay between Long Island and the barrier beaches of Fire Island in New York, Isle of Wight Bay, which separates Ocean City, Maryland from the rest of Worcester County, Banana River in Florida, Lake Illawarra in New South Wales, Montrose Basin in Scotland, Broad Water in Wales have all been classified as lagoons, despite their names. In England, The Fleet at Chesil Beach has been described as a lagoon. In Latin America, the term laguna in Spanish, which lagoon translates to, may be used for a small fresh water lake in a similar way a creek is considered a small river.
However, sometimes it is popularly used to describe a full-sized lake, such as Laguna Catemaco in Mexico, the third largest lake by area in the country. The brackish water lagoon may be thus explicitly identified as a "coastal lagoon". In Portuguese the same usage is found: lagoa may be a body of shallow sea water, or a small freshwater lake not linked to the sea. Lagoon is derived from the Italian laguna, which refers to the waters around Venice, the Lagoon of Venice. Laguna is attested in English by at least 1612, had been Anglicized to "lagune" by 1673. In 1697 William Dampier referred to a "Lake of Salt water" on the coast of Mexico. Captain James Cook described an island "of Oval form with a Lagoon in the middle" in 1769. Atoll lagoons form as coral reefs grow upwards while the islands that the reefs surround subside, until only the reefs remain above sea level. Unlike the lagoons that form shoreward of fringing reefs, atoll lagoons contain some deep portions. Coastal lagoons form along sloping coasts where barrier islands or reefs can develop off-shore, the sea-level is rising relative to the land along the shore.
Coastal lagoons do not form along steep or rocky coasts, or if the range of tides is more than 4 metres. Due to the gentle slope of the coast, coastal lagoons are shallow, they are sensitive to changes in sea level due to global warming. A relative drop in sea level may leave a lagoon dry, while a rise in sea level may let the sea breach or destroy barrier islands, leave reefs too deep under water to protect the lagoon. Coastal lagoons are young and dynamic, may be short-lived in geological terms. Coastal lagoons are common. In the United States, lagoons are found along more than 75 percent of the Gulf coasts. Coastal lagoons are connected to the open ocean by inlets between barrier islands; the number and size of the inlets, precipitation and inflow of fresh water all affect the nature of the lagoon. Lagoons with little or no interchange with the open ocean, little or no inflow of fresh water, high evaporation rates, such as Lake St. Lucia, in South Africa, may become saline. Lagoons with no connection to the open ocean and significant inflow of fresh water, such as the Lake Worth Lagoon in Florida in the middle of the 19th century, may be fresh.
On the other hand, lagoons with many wide inlets, such as the Wadden Sea, have strong tidal currents and mixing. Coastal lagoons tend to accumulate sediments from inflowing rivers, from runoff from the shores of the lagoon, from sediment carried into the lagoon through inlets by the tide. Large quantities of sediment may be be deposited in a lagoon when storm waves overwash barrier islands. Mangroves and marsh plants can facilitate the accumulation of sediment in a lagoon. Benthic organisms may destabilize sediments. River-mouth lagoons on mixed sand and gravel beaches form at the river-coast interface where a braided, although sometimes meandering, river interacts with a coastal environment, affected by longshore drift; the lagoons which form on the MSG coastlines are common on the east coast of the South Island of New Zealand and have long been referred to as hapua by the Māori. This classification differentiates hapua from similar lagoons located on the N
Common bottlenose dolphin
The common bottlenose dolphin, or Atlantic bottlenose dolphin, is the most well-known species from the family Delphinidae. Common bottlenose dolphins are the most familiar dolphins due to the wide exposure they receive in captivity in marine parks and dolphinaria, in movies and television programs; the common bottlenose dolphin is the largest species of the beaked dolphins. They inhabit temperate and tropical oceans throughout the world, are absent only from polar waters; until all bottlenose dolphins were considered as a single species, but now the Indo-Pacific bottlenose dolphin and Burrunan dolphin have been split from the common bottlenose dolphin. While named as the bottlenose dolphin, this term is now applied to the genus as a whole; the dolphins inhabit temperate seas worldwide. As considerable genetic variation has been described among members of this species between neighboring populations, many experts consider that additional species may be recognized; the common bottlenose dolphin is grey in color and may be between 2 and 4 m long, weighs between 150 and 650 kg.
Males are larger and heavier than females. In most parts of the world, the adult's length is between 2.5 and 3.5 m with weight ranging between 200 and 500 kg. Newborn calves weigh between 15 and 30 kg, they can live as long as 40–50 years. Sexual maturity varies by population, ranges from 5–14 years of age. Dolphins have a short and well-defined snout that looks like an old-fashioned gin bottle, the source for their common name. Like all whales and dolphins, the snout is not a functional nose, their necks are more flexible than other dolphins' due to five of their seven vertebrae not being fused together as is seen in other dolphin species. Common bottlenose dolphins live in groups called pods that number about 15 individuals, but group size varies from pairs of dolphins to over 100 or occasionally over 1000 animals for short periods of time, their diets consist of eels, squid and wide variety of fishes. They do not chew their food. Dolphin groups work as a team to harvest schools of fish, though they hunt individually.
Dolphins search for prey using echolocation, a form of sonar. They emit clicking sounds and listen for the return echoes to determine the location and shape of nearby items, including potential prey. Dolphins use sound for communication, including squeaks emitted from the blowhole, whistles emitted from nasal sacs below the blowhole, sounds emitted through body language, such as leaping from the water and slapping their tails on the water, their heads contain an oily substance that both acts as an acoustic lens and protects the brain case. The average life expectancy of common bottlenose dolphins is about 17 years old, but in captivity they have been known to live to up to 51 years old; the common bottlenose dolphin can be found in the temperate and tropical oceans worldwide. Some bottlenose populations live closer to the shore and others live further out to sea. Offshore populations are larger and have proportionally shorter fins and beaks. Offshore populations can migrate up to 4,200 km in a season, but inshore populations tend to move less.
However, some inshore populations make long migrations in response to El Niño events. The species has occurred as far as 50° north in eastern Pacific waters as a result of warm water events; the coastal dolphins appear to adapt to shallow waters. It has larger flippers, for maneuverability and heat dispersal, they can be found in harbors, bays and estuaries. Offshore dolphins, are adapted to cooler, deeper waters. Certain qualities in their blood suggest, their larger body protects them against predators and helps them retain heat. The common bottlenose dolphin has a bigger brain than humans. Numerous investigations of bottlenose dolphin intelligence include tests of mimicry, use of artificial language, object categorization, self-recognition; this intelligence has driven considerable interaction with humans. Common bottlenose dolphins are popular in aquarium shows and television programs such as Flipper, they have been trained for military uses such as locating sea mines or detecting and marking enemy divers, as for example in the U.
S. Navy Marine Mammal Program. In some areas, they cooperate with local fishermen by driving fish toward the fishermen and eating the fish that escape the fishermen's nets; some interactions with humans are harmful to the dolphins. Dolphin hunting industry exists in multiple countries including Japan, where common bottlenose dolphins are hunted for food annually in the town of Taiji, the Faroe Islands. Dolphins are sometimes killed inadvertently as a bycatch of tuna fishing. Tião was a well-known solitary male bottlenose dolphin, first spotted in the town of São Sebastião in Brazil around 1994 and allowed humans to interact with it; the dolphin became infamous for killing a swimmer and injuring many others, which earned it the nickname of killer dolphin. The North Sea, Baltic and Black Sea populations of the common bottlenose dolphin are listed on Appendix II of the Convention on the Conservation of Migratory Species of Wild Animals of the Bonn Convention), since they have an unfavorable conservation status or would benefit from international coop
Florida East Coast Railway
The Florida East Coast Railway is a Class II railroad operating in the U. S. state of Florida owned by Grupo México. The FEC was a Class I railroad owned by Florida East Coast Industries from 2000 to 2016, FOXX Holdings between 1983 and 2000, the St. Joseph Paper Company prior to 1983. Built in the last quarter of the 19th century and the first decade of the 20th century, the FEC was a project of Standard Oil principal Henry Flagler, he visited Florida with his first wife, Mary. A key strategist who worked with John D. Rockefeller building the Standard Oil Trust, Flagler noted both great potential and a lack of services during his stay at St. Augustine, he subsequently began what amounted to his second career, developing resorts and communities all along Florida's shores abutting the Atlantic Ocean. The FEC is best known for building the railroad to Key West, completed in 1912; when the FEC's line from the mainland to Key West was damaged by the Labor Day Hurricane of 1935, the State of Florida purchased the remaining right-of-way and bridges south of Dade County, they were rebuilt into road bridges for vehicle traffic and became known as the Overseas Highway.
However, a greater and lasting Flagler legacy was the developments along Florida's eastern coast. During the Great Depression, control was purchased by heirs of the du Pont family. After 30 years of fragile financial condition, the FEC, under leadership of a new president, Ed Ball, took on the labor unions. Ball claimed the company could not afford the same costs as larger Class 1 railroads and needed to invest saved funds in its infrastructure, the condition of, fast becoming a safety issue; the company—using replacement workers—and some of its employees engaged from 1963 until 1977 in one of the longest and more violent labor conflicts of the 20th century. Federal authorities had to intervene to stop the violence, which included bombings and vandalism. However, the courts ruled in the FEC's favor with regard to the right to employ strikebreakers. During this time Ball invested in numerous steps to improve the railroad's physical plant, installed various forms of automation; the FEC was the first US railroad to operate two-man train crews, eliminate cabooses, end all of its passenger services by 1968.
In modern times, the company's primary rail revenues come from its rock trains. In January 2018, passenger rail service Brightline began using FEC tracks for its route from West Palm Beach to Fort Lauderdale; the Florida East Coast Railway was developed by Henry Morrison Flagler, an American tycoon, real estate promoter, railroad developer and John D. Rockefeller's partner in Standard Oil. Formed at Cleveland, Ohio as Rockefeller, Andrews & Flagler in 1867, Standard Oil moved its headquarters in 1877 to New York City. Flagler and his family relocated there as well, he was joined by Henry H. Rogers, another leader of Standard Oil who became involved in the development of America's railroads, including those on nearby Staten Island, the Union Pacific, in West Virginia, where he built the remarkable Virginian Railway to transport coal to Hampton Roads, Virginia. Flagler's non-Standard Oil interests went in a different direction, when in 1878, on the advice of his physician, he traveled to Jacksonville, Florida for the winter with his first wife, quite ill.
Two years after she died in 1881, he married Ida Alice Shourds. After their wedding, the couple traveled to St. Augustine, Florida in 1883. Flagler found the city charming, he recognized Florida's potential to attract out-of-state visitors. Though Flagler remained on the Board of Directors of Standard Oil, he gave up his day-to-day involvement in the firm in order to pursue his Florida interests; when Flagler returned to Florida, in 1885 he began building a grand St. Augustine hotel, the Ponce de Leon Hotel. Flagler realized that the key to developing Florida was a solid transportation system, purchased the 3 ft narrow gauge Jacksonville, St. Augustine and Halifax River Railway on December 31, 1885, he discovered that a major problem facing the existing Florida railway systems was that each operated on different gauge systems, making interconnection impossible. He converted the line to 4 ft 8 1⁄2 in standard gauge in 1890 and the small operation was incorporated in 1892; the earliest predecessor of the FEC was the narrow gauge St. John's Railway, incorporated in 1858, which constructed a now-abandoned line between St. Augustine and Tocoi, a small settlement on the east bank of the St. Johns River, midway between Palatka and Green Cove Springs.
In 1883, Henry Flagler, now retired from Standard Oil, moved to St. Augustine, built the mentioned Ponce de Leon and the Alcazar Hotels, purchased the Casa Monica, just east of the Alcazar, changing the name to Cordova; the east coast of Florida was undeveloped at that time, Flagler found it difficult to obtain the construction materials he needed. His purchase of the JStA&HR Railway was intended to make it faster and easier to supply his building projects; the JStA&HR Railway served the northeastern portion of the state and was the first operation in the Flagler Railroad system. Before Flagler bought the line, the railroad stretched only between South Jacksonville and St. Augustine and lacked a depot sufficient to accommodate travelers to his St. Augustine resorts, he built a modern depot facility as well as schools, h
Sponges, the members of the phylum Porifera, are a basal Metazoa clade as a sister of the Diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through them, consisting of jelly-like mesohyl sandwiched between two thin layers of cells; the branch of zoology that studies sponges is known as spongiology. Sponges have unspecialized cells that can transform into other types and that migrate between the main cell layers and the mesohyl in the process. Sponges do not have digestive or circulatory systems. Instead, most rely on maintaining a constant water flow through their bodies to obtain food and oxygen and to remove wastes. Sponges were first to branch off the evolutionary tree from the common ancestor of all animals, making them the sister group of all other animals; the term sponge derives from the Ancient Greek word σπόγγος. Sponges are similar to other animals in that they are multicellular, lack cell walls and produce sperm cells.
Unlike other animals, they lack true organs. Some of them are radially symmetrical; the shapes of their bodies are adapted for maximal efficiency of water flow through the central cavity, where it deposits nutrients, leaves through a hole called the osculum. Many sponges have internal skeletons of spongin and/or spicules of calcium carbonate or silicon dioxide. All sponges are sessile aquatic animals. Although there are freshwater species, the great majority are marine species, ranging from tidal zones to depths exceeding 8,800 m. While most of the 5,000–10,000 known species feed on bacteria and other food particles in the water, some host photosynthesizing microorganisms as endosymbionts and these alliances produce more food and oxygen than they consume. A few species of sponge that live in food-poor environments have become carnivores that prey on small crustaceans. Most species use sexual reproduction, releasing sperm cells into the water to fertilize ova that in some species are released and in others are retained by the "mother".
The fertilized eggs form larvae to settle. Sponges are known for regenerating from fragments that are broken off, although this only works if the fragments include the right types of cells. A few species reproduce by budding; when conditions deteriorate, for example as temperatures drop, many freshwater species and a few marine ones produce gemmules, "survival pods" of unspecialized cells that remain dormant until conditions improve and either form new sponges or recolonize the skeletons of their parents. The mesohyl functions as an endoskeleton in most sponges, is the only skeleton in soft sponges that encrust hard surfaces such as rocks. More the mesohyl is stiffened by mineral spicules, by spongin fibers or both. Demosponges use spongin, in many species, silica spicules and in some species, calcium carbonate exoskeletons. Demosponges constitute about 90% of all known sponge species, including all freshwater ones, have the widest range of habitats. Calcareous sponges, which have calcium carbonate spicules and, in some species, calcium carbonate exoskeletons, are restricted to shallow marine waters where production of calcium carbonate is easiest.
The fragile glass sponges, with "scaffolding" of silica spicules, are restricted to polar regions and the ocean depths where predators are rare. Fossils of all of these types have been found in rocks dated from 580 million years ago. In addition Archaeocyathids, whose fossils are common in rocks from 530 to 490 million years ago, are now regarded as a type of sponge; the single-celled choanoflagellates resemble the choanocyte cells of sponges which are used to drive their water flow systems and capture most of their food. This along with phylogenetic studies of ribosomal molecules have been used as morphological evidence to suggest sponges are the sister group to the rest of animals; some studies have shown that sponges do not form a monophyletic group, in other words do not include all and only the descendants of a common ancestor. Recent phylogenetic analyses suggest that comb jellies rather than sponges are the sister group to the rest of animals; the few species of demosponge that have soft fibrous skeletons with no hard elements have been used by humans over thousands of years for several purposes, including as padding and as cleaning tools.
By the 1950s, these had been overfished so that the industry collapsed, most sponge-like materials are now synthetic. Sponges and their microscopic endosymbionts are now being researched as possible sources of medicines for treating a wide range of diseases. Dolphins have been observed using sponges as tools while foraging. Sponges constitute the phylum Porifera, have been defined as sessile metazoans that have water intake and outlet openings connected by chambers lined with choanocytes, cells with whip-like flagella. However, a few carnivorous sponges have lost the choanocytes. All known living sponges can remold their bodies, as most types of their cells can move within their bodies and a few can change from one type to another. If a few sponges are able to produce mucus – which acts as a microbial barrier in all other animals – no sponge with the ability to secrete a functional mucus layer has been recorded. Without such a mucus layer their living tissue is covered by a layer of microbial symbionts, which can contribute up to 40–50% of the sponge wet mass.
This inability to prevent microbes from penetrating their porous tissue could be a major reason why they have never evolved a more complex anatomy. Like cnidarians (jellyfish, e
Inline skating is a multi-disciplinary sport and can refer to a number of activities practiced using Inline skates. Inline skates have two to five polyurethane wheels, arranged in a single line by a metal or plastic frame on the underside of a boot; the in-line design allows for greater maneuverability than traditional roller skates. Following this basic design principle, inline skates can be modified to varying degrees to accommodate niche disciplines. Inline skating is referred to by the proprietary eponym "rollerblading", or just "blading", due to the popular brand of inline skates, Rollerblade; the German branch of SKF developed and produced inline-skates in 1978 with wheels for hockey or for the street. The product was stopped after one year as the management do not wanted a consumer product in the portfolio. Other inline skates were developed as a substitute for ice skates, Life magazine published a photo of American skater Eric Heiden, training for the 1980 Olympics, using such skates on a Wisconsin road.
In 1980, a group of ice hockey players in Minneapolis, Minnesota were looking for a way to practice during the summer. Scott and Brennan Olson formed the company Rollerblade, Inc. to sell skates with four polyurethane wheels arranged in a straight line on the bottom of a padded boot. They sold the company in 1984 to Bob Naegele jr. who advertised to the general public and sold millions. Aggressive skating is a sub discipline focused on the execution of tricks in the action sports cannon. Aggressive inline skates are specially modified to accommodate the jumping of large gaps. Aggressive skates are identifiable by a prominent gap in between the second and third wheels which allows for grinds perpendicular to the direction of the wheels. A hard plastic surface on the sole of the boot known as a "Sole plate" or "Soul Plate" allows grinds parallel to the direction of the wheels. From these grind surfaces comes a lexicon of well known grind stances, though sliding can occur on any surface of the boot or wheels.
Aggressive skates have much smaller wheels than a traditional inline skates. The small size allows for more freedom. Additionally these small wheels feature a flat profile to accommodate the impact from jumping tall heights. Park skating refers to doing tricks within a skatepark, meaning a space, designed for skating and laid out as such. Street skating refers to tricks performed on non-allocated obstacles. Artistic roller skaters use either inline skates; the sport looks similar to its counterpart on ice, but more affordable in warmer climates. Inline figure skating has been included in the world championships since 2002. Recreational skaters skate on roads, bike lanes, or paved trails, they might be skating solo for transportation or fitness, skating with friends, or participating in an organized event. Because urban areas tend to have more hazards from traffic, many cities have organized social groups to make skating safer. Fitness skaters tend to skate more and go longer distances. Fitness skates have faster bearings and larger wheels to generate speed and cover ground more efficiently.
Skaters in this category tend to skate 10-15 mph on average. Some challenge themselves to feats of endurance skating for 30+ miles. Freestyle skating is a form of inline skating performed on flat ground and refers collectively to the disciplines for which competitions are organized by the International Freestyle Skaters Association. IFSA has defined three disciplines which must be offered by any competition they sanction: freestyle slalom, speed slalom, free jump. Two additional disciplines, high jump and jam, are defined, but are at present considered optional. Hockey performed in a special rink on inline skates Originally thought up by ice hockey players who wanted to continue training in their off season. Hockey rollerblades have wheel sizes in the 70-78mm range; the toe end of the boot is characteristically squared off. The feel of the boot is the same as ice skates, so the switch off between hockey skates and hockey is diminished- leading to better in-training simulations of ice hockey. Five-a-side football on skates taking place in an indoor sports hall or outside space with appropriate demarcation Also known as inline racing, speed skating is the sport of skating with the intent to beat the opponent's time score or get to the finish line first.
A term used to refer to inline skates on a vert ramp, a half pipe with some vertical in it between 6in to 24in. Vert skating is a form of gymnastics performed with skates; the purpose of vert skating is to perform spins or flips. It flips; the intent of the skater is to build speed until they are of sufficient height above the edge of the ramp to perform various aerial acrobatics. In competitions skaters have limited time less than a minute, to impress the judges by landing numerous and difficult tricks. Vert skating was once part of the X Games. Vert ramps are present in many skateparks. Inline skating at Curlie