Red mangrove (Rhizophora mangle)

MangroveThe red mangrove has an extensive range, and is found in estuaries and lagoons along the west coast of Africa, on the other side of the Atlantic from northern Brazil through Central America to the southern coast of Florida, and on the Pacific coast from Ecuador to Baja, California. Mangrove forests are an incredibly important ecosystem in the tropical regions of the world. Red mangroves are particularly significant, because as they are found at the water’s edge, their submerged roots provide a nursery habitat to fish and crustaceans. They also provide habitat for a number of mammals, birds, and reptiles, including species of concern like the American crocodile, Florida panther, and West Indian manatee.

About the TreeMangrove leaves

The red mangrove can grow to be anywhere from 3-20 meters tall with thick leaves and flowers with four yellow-green sepals and four creamy white petals.  The seed germinates while still on the tree and can grow to be 30 centimeters in length. Once it reaches this length, it falls into the water and is then carried down the waterway until it latches on to sediments and begins to grow. However, this process can take many months; therefore, as a survival adaptation, the seed can survive up to a year in the water.

Survival Adaptations of the Red Mangrove

Prop Roots

The red mangrove uses prop roots as support and as a means of obtaining oxygen. In the tropical regions of the world the healthy viable soil is very shallow. This means that trees have to grow their roots outwards instead of deeper into the ground like North American trees do. This causes tropical trees to be very unstable on their own; therefore they have to have a means of stabilizing themselves. The red mangrove uses prop roots, which extend from the trunk in every direction, to keep it upright. Also, since the red mangrove is a tree that grows in areas where the ocean meets the land, most of their roots are submerged. But with the use of their aerial prop roots, they can obtain oxygen at all times and can also expel other gasses.

Prevention of Salt Entering the Tissues

The red mangrove lives in areas that have high salinity levels. To survive they must have the ability to either excrete the excess salt or only let in certain levels of salt. It is a species that use root membranes to only allow the right amount of salt into their tissues. “The Red Mangrove is a salt excluder separating freshwater at the root surface by creating a type of non-metabolic ultra filtration system. Transpiration at the leaf surface creates negative pressure in the xylem. This causes a type of “reverse osmosis” to occur at the root surface” (Seacamp Association).

Environmental Benefits of the Red Mangrove


Since red mangroves grow on the coastal areas of the tropical region of the world they are constantly barraged with strong waves. Using prop roots, they can withstand storms and harsh currents. These trees also buffer coastal residential areas from hurricanes and tsunamis. Not only do they help protect human life but they also help stop the erosion of the land. When storms hit the land, waves cause the shore sediment to be pushed into the ocean thereby slowly eroding the land. However, the red mangrove tree roots hold the sediment in place. This accumulated process of holding sediment contributes to the formation of islands. One seed will latch on to a small amount of sand and begin to grow. Eventually, once the seedling has grown prop roots, more sediment will begin to accumulate. Then more seeds will latch on and therefore a larger amount of sediment is accumulated which then continues to grow over time and become an actual island.


The submerged prop roots of the red mangrove are used by marine organisms as a breeding ground and nursery for their young. Since the tree acts as a buffer, the area around the mangle (a group of mangrove trees) is typically calm which makes it a perfect place for organisms lower on the food chain to hide from the bigger predators. Marine organisms are not the only type of animal that takes refuge among its roots. Birds, insects, and even some mammals live in mangles.

Terrestrial Animals of the Mangrove Forests

Mangrove cuckooCoccyzus minor, also known as the mangrove cuckoo, is very common in mangles. It usually nests 2-3 meters above water in a mangrove tree. The nest is a relatively flat platform of twigs and leaves. The female lays 2-4 eggs with both adults sharing in feeding the young bird. The mangrove cuckoo prefers caterpillars and grasshoppers, but will also take other insects, spiders, snails, small lizards, and fruit.

Mangrove warblerThe mangrove warbler (Erithachorides group) tends to be larger than other yellow warbler subspecies groups, averaging 12.5 cm (4.9 in) in length and 11 g (0.39 oz) in weight. It is resident in the mangrove swamps of coastal Central America and northern South America; These birds are found on the oceanic Galápagos Islands. The summer males differ from those of the yellow warbler in that they have a rufous hood or crown. The races in this group vary in the extent and hue of the hood, overlapping extensively with the golden warbler group in this character.

Mangrove isopodSphaeroma terebrans, a mangrove isopod, inhabits the red mangrove forests. They burrow into the prop roots for food and protection. This behavior can cause death in that particular limb of the tree. The prop roots that survive will branch out of the burrowed hole. Sphaeroma terebrans is typically 8-10 millimeters long and is found throughout the Gulf of Mexico, Florida, and Central America. These isopods will also bore into boats, wooden pilings and other wooden structures.

Mangrove tree crabAratus pisonii, commonly known as the mangrove tree crab, is a species of crab which lives in mangrove trees in tropical and subtropical parts of the Americas. It feeds mostly on the leaves, but it is an omnivore and prefers animal matter when possible. This species is quite small with the males averaging around 2 centimeters long and females slightly smaller. The eyes are set far apart and the carapace is wider at the front than at the back. It is mottled brown and olive color which helps the crab to blend in with its surroundings. This crab is completely terrestrial, meaning it does not ever live in the water. Because of this the Aratus pisonii will ascend the tree when the tide comes in and then burrows in the mud when the tide goes back out.

Mangrove oysterThe mangrove oyster, or Crassostrea gasar, is a true oyster in the Ostreidae family. The mangrove oyster is found in tropical intertidal zones, where it grows on the bark of the stilt sections of mangrove trees, which are exposed during low tides and covered during high tides. It can also be found on some other suitable intertidal substrates in its range. This oyster has evolved to survive exposed to the air during low tides. The mangrove oyster is found on Caribbean and Atlantic South American shorelines, and West African shorelines.

The Coral Reefs of Central America

What is a coral reef?

graph of coral reefA coral reef is a collection of coral polyps encased in calcium carbonate. With every new generation of coral polyps, more calcium carbonate will build up and the reef grows larger. However, it has taken thousands of years for the coral reefs to have grown to the size they are today. The individual coral polyps look very similar to sea anemones but are on a much smaller scale. Also like sea anemones they belong to the same cnidarian class, class Anthozoa. Coral polyps, like all cnidarians, have stinging cells in their tentacles called nematocysts. They use nematocysts to stun microscopic prey and then move it to their mouths which is in the center of the tentacles. Coral polyps also have a symbiotic relationship with dinoflagellates. Dinoflagellates live inside of the polyps and use the energy from the sun to make ATP and then give it to the polyp. Also the dinoflagellates give the coral its color and without them the coral would look bleached and would eventually starve. As a whole, coral reefs act as nurseries for marine life. All kinds of creatures live under the protection of the coral reef. Here it is typically harder for large predators to prey on the smaller organisms. This helps the creatures to safely lay eggs and raise their young. Coral reefs also act as buffers for mangrove forests during storms. They also help stop the harsh waves that erode land masses.

hard brain coralHard Coral

Hard corals are made of a rigid calcium carbonate (limestone) and appear very much like rocks. Each polyp secretes a hard exoskeleton made up of calcium carbonate and a chalky internal skeleton that stays in place even after they die. As each generation of polyps dies and their exoskeleton remains, the coral grows a bit larger and because each polyp is so small, hard corals grow at a very very slow rate. Hard corals are scientifically known as “scleractinians.”

Brain Coral is a common name given to corals in the family Faxildae, so called due to their generally spheroid shape and grooved surface which resembles a brain. Each head of coral is formed by a colony of genetically identical polyps which secrete a hard skeleton of calcium carbonate; this makes them important coral reef builders. Brain corals are found in shallow warm-water reefs in all the world’s oceans. The lifespan of the largest brain coral is about 900 years. Colonies can grow as large as 1.8 meters or more in height. Brain corals extend their tentacles at night to catch food. During the day, they use their tentacles for protection by wrapping them over the grooves on their surface. The surface is hard and offers good protection against fish and storms.

Staghorn coralStaghorn coral (Acropora cervicornis) is a branching coral with cylindrical branches ranging from a few centimeters to over 2 meters in length.This coral exhibits the fastest growth of all known western Atlantic corals, with branches increasing in length by 10-20 centimeters per year and is one of the three most important Caribbean corals in terms of its contribution to reef growth and fish habitat.

Elkhorn coralElkhorn coral (Acropora palmata) is considered to be one of the most important reef-building corals in the Caribbean. This species of coral is structurally complex with many large branches. The coral structure closely resembles that of elk antlers, and is a popular choice as a home for lobsters, parrotfish, snappers and other reef fish. Elkhorn coral colonies are incredibly fast growing with an average growth rate of 5 to 10 centimeters per year and can eventually grow up to 3.7 meters in diameter.

Soft Coral

Soft corals are also composed of some rigid calcium carbonate, but it is blended with protein so it is less rigid than hard corals. These corals are “rooted,” but because they have no exoskeletons, they sway back and forth with the currents, appearing to be more like plants blowing in the breeze.

gorgonian coralGorgonian: This family of soft coral is also called sea whips or sea fans. Individual tiny polyps form colonies that are normally erect, flattened, branching, and reminiscent of a fan. Others may be whiplike, bushy or even encrusting. A colony can be several meters high and across but only a few centimeters thick. They may be brightly colored, often purple, red, or yellow. Gorgonians are found primarily in shallow waters, though some have been found at depths of several thousand meters. The size, shape, and appearance of the gorgonians are highly correlated with their location. The more fan-shaped and flexible gorgonians tend to populate shallower areas with strong currents, while the taller, thinner and stiffer gorgonians can be found in deeper, calmer waters.

tree coralTree Corals (family-Nephtheidae): These flowery soft corals are commonly seen on many of our shores. They are usually attached to hard surfaces including boulders, jetty pilings and coral rubble. These soft corals look like bushes. The common tissue is generally rubbery but rough to the touch. A thick ‘main trunk’ attaches to a hard surface on one end, with many small branches on the other end which is why they are referred to as Tree Coral. The Carnation Coral Dendronephthya belong to this family of soft corals.

Organisms of the Coral Reef

Bony Fish

French angelfishThe Pomacanthus paru, also known as the french angelfish, is one of many fish that are commonly found in coral reefs. This fish is found in the Western Atlantic from New York down to the Bahamas, and also the Gulf of Mexico and the Caribbean. They live at depths between 2 and 100 meters. They typically grow to be about 41 centimeters. The french angelfish is commonly found in shallow reefs and are normally found in pairs. It feeds on sponges, algae, bryozoans, zoantharia, gorgonians, and tunicates. The adult background coloration is black but the scales of the body are rimmed with golden yellow. Also the pectoral fins have a orange-yellow bar, the chin is whitish and the outer part of the iris is yellow.

parrotfishThe stoplight parrotfish (Sparisoma viride) is a species of parrotfish inhabiting coral reefs in Florida, Caribbean Sea, Gulf of Mexico, Bermuda and as far south as Brazil. Like most of its relatives, it is able to change sex. Its typical length is between 30 and 46 cm, but it can reach 61 cm at times. It is normally found during the day at depths between 4.6 and 24.4 m. Stoplight parrotfish live on reefs, depending on the shelter, protection, and nutrition that densely packed coral provides. In particular, the 1-2 cm wide tubes of branched finger coral (Porites porites) provide shelter and protection as well as a food source (algae) to juveniles. Young may also be found in seagrass beds. Adults often reside in shallower waters, usually over reef bases. These fish are most commonly found in clear waters at depths of 3-50 m.

Cartilaginous fish

nurse sharkGinglymostoma cirratum, also known as the nurse shark, is a shark in the family Ginglymostomatidae. Nurse sharks can reach a length of 4.3 meters and a weight of 330 kg. The nurse shark is a common inshore bottom-dwelling shark, found in tropical and subtropical waters on the continental and insular shelves. It is frequently found at depths of one meter or less but may occur down to 75 meters. Its common habitats are reefs, channels between mangrove islands, and sand flats. It can be seen in the Western Atlantic from Rhode Island down to southern Brazil, in the Eastern Atlantic from Cameroon to Gabon (and possibly ranges further north and south), and around the islands of the Caribbean. The nurse shark is not widely commercially fished but because of its sluggish behavior it is an easy target for local fisheries. Its skin is exceptionally tough and is prized for leather; its flesh is consumed fresh and salted and its liver is utilized for oil. It is not taken as a game fish. It has been reported in some unprovoked attacks on humans but is not generally perceived as a threat. Divers have often provoked the shark, however, by grabbing a motionless specimen by the tail.


cnidarianscyphozoaAnthozoa is a class within the phylum Cnidaria. Corals and sea anemones are the two cnidarians that fall under the class Anthozoa. Unlike other cnidarians, anthozoans do not have a medusa stage in their development. Instead, they release sperm and eggs that form a planula, which attaches to some substrate on which the cnidarian grows. Some anthozoans can also reproduce asexually through budding. Like those of other cnidarians, the individual polyps have a cylindrical body crowned by a ring of tentacles surrounding the mouth. The mouth leads into a tubular pharynx which descends for some distance into the body before opening into the gastrovascular cavity that fills the interior of the body and tentacles. Unlike other cnidarians, however, the cavity is subdivided by a number of radiating partitions, or mesenteries. The gonads are also located within the cavity walls. All cnidarian species can feed by catching prey with nematocysts; sea anemones are capable of catching fish and corals of catching plankton. Some of the species also harbor a type of algae, dinoflagellates called zooxanthellae, in a symbiotic relationship. The reef building corals, known as hermatypic corals, rely on this symbiotic relationship particularly. The zooxanthellae benefit by using nitrogenous waste and carbon dioxide produced by the host, and the cnidarian gains photosynthetic capability and increased calcium carbonate production in hermatypic corals.

graphThe Scyphozoa are a class within the phylum Cnidaria, sometimes referred to as the "true jellyfish." Most species of Scyphozoa have two life history phases, including the planktonic medusa or jellyfish form, which is most evident in the warm summer months, and an inconspicuous but longer-lived bottom-dwelling polyp, which seasonally gives rise to new medusae. Most of the large, often colorful and conspicuous jellyfish found in coastal waters throughout the world are Scyphozoa. They typically range from 2 to 40 cm in diameter. Scyphozoans usually display a four-part symmetry and have an internal gelatinous material called mesoglea, which provides the same structural integrity as a skeleton. The mesoglea includes mobile amoeboid cells originating from the epidermis. The mouth opens into a central stomach, from which four interconnected diverticula radiate outwards. In many species, this is further elaborated by a system of radial canals, with or without an additional ring canal towards the edge of the dome. Some genera, such as Cassiopea or upside-down jellyfish, even have additional, smaller mouths in the oral arms. The lining of the digestive system includes further stinging nematocysts, along with cells that secrete digestive enzymes. Most species appear to be gonochorists, with separate male and female individuals. The gonads are located in the stomach lining, and the mature gametes are expelled through the mouth. After fertilization, some species brood their young in pouches on the oral arms, but they are more commonly planktonic.The fertilized egg produces a planular larva which, in most species, quickly attaches itself to the sea bottom. The larva develops into the hydroid stage of the lifecycle, a tiny sessile polyp called a scyphistoma. The scyphistoma reproduces asexually, producing similar polyps by budding, and then either transforming into a medusa, or budding several medusae off from its upper surface. The medusae are initially microscopic, and may take years to reach sexual maturity.

Box JellyfishBox jellyfish (class Cubozoa) are cnidarians distinguished by their cube-shaped medusae. Some species of box jellyfish produce extremely potent venom: Chironex fleckeri, Carukia barnesi and Malo kingi. Stings from these and a few other species in the class are extremely painful and can be fatal to humans. The medusa form of a box jellyfish has a squarish, box-like bell. From each of the four lower corners of this hangs a short pedalium or stalk which bears one or more long, slender, hollow tentacles. The rim of the bell is folded inwards to form a shelf known as a velarium which restricts the bell's aperture and creates a powerful jet when the bell pulsates. As a result, box jellyfish can move more rapidly than other jellyfish; in fact, speeds of up to six meters per minute have been recorded. In the center of the underside of the bell is a mobile appendage called the manubrium which somewhat resembles an elephant's trunk. At its tip is the mouth. The interior of the bell is known as the gastrovascular cavity. It is divided by four equidistant septa into a central stomach and four gastric pockets. The eight gonads are located in pairs on either side of the four septa. The margins of the septa bear bundles of small gastric filaments which house nematocysts and digestive glands and help to subdue prey. Each septum is extended into a septal funnel that opens onto the oral surface and facilitates the flow of fluid into and out of the animal.

hydrozoaHydrozoa are a taxonomic class of individually very small, predatory animals, some solitary and some colonial, most living in salt water. The colonies of the colonial species can be large, and in some cases the specialized individual animals cannot survive outside the colony. A few genera within this class live in freshwater. Hydrozoans are related to jellyfish and corals and belong to the phylum Cnidaria. Most hydrozoan species include both a polypoid and a medusoid stage in their lifecycles, although a number of them have only one or the other. For example, Hydra has no medusoid stage, while Liriope lacks the hydroid stage. The hydroid form is usually colonial, with multiple polyps connected by tubelike hydrocauli. The hollow cavity in the middle of the polyp extends into the associated hydrocaulus, so that all the individuals of the colony are intimately connected. Where the hydrocaulus runs along the substrate, it form a horizontal root-like stolon that anchors the colony to the bottom. The medusae of hydrozoans are smaller than those of typical jellyfish, ranging from 0.5 to 6 cm in diameter. Although most hydrozoans have a medusoid stage, this is not always free-living, and in many species, exists solely as a sexually reproducing bud on the surface of the hydroid colony. Sometimes, these medusoid buds may be so degenerated as to entirely lack tentacles or mouths, essentially consisting of an isolated gonad.


molluscaThe Bivalvia are the bivalve mollusks and include oysters, clams, and scallops. The example to the right is the rock piddock, Pholas chiloensis. This bivalve burrows into rock, shells, or wood. It is responsible for many of the burrows you see in the beachrock. Members of the phylum Mollusca often have a muscular foot which they use to push their way through a substrate. Although externally often symmetrical about a plane between the shells, internally they have no obvious symmetry.

cephalopodCephalopods are exclusively marine animals that are characterized by bilateral body symmetry, a prominent head, and a set of arms or tentacles modified from the primitive molluscan foot. The two most common cephalopods are the octopi and the squid. Cephalopods are widely regarded as the most intelligent of the invertebrates, and have well developed senses and large brains (larger than those of gastropods). The nervous system of cephalopods is the most complex of the invertebrates and their brain-to-body-mass ratio falls between that of endothermic and ectothermic vertebrates. The brain is protected in a cartilaginous cranium. The giant nerve fibers of the cephalopod mantle have been widely used for many years as experimental material in neurophysiology; their large diameter (due to lack of myelination) makes them relatively easy to study compared with other animals. Cephalopods are social creatures; when isolated from their own kind, they will sometimes shoal with fish. Most cephalopods possess chromatophores - colored pigment cells that expand and contract in accordance with their counterparts to produce color and pattern - which they can use in a startling array of fashions. As well as providing camouflage with their background, some cephalopods bioluminesce, shining light downwards to disguise their shadows from any predators that may lurk below. The bioluminescence is produced by bacterial symbionts; the host cephalopod is able to detect the light produced by these organisms. Bioluminescence may also be used to entice prey, and some species use colorful displays to impress mates, startle predators, or even communicate with one another. It is not certain whether bioluminescence is actually of epithelial origin or if it is a bacterial production.


brittle starstarBrittle stars or ophiuroids are echinoderms in the class Ophiuroidea and are closely related to starfish. They crawl across the sea floor using their flexible arms for locomotion. The ophiuroids generally have five long, slender, whip-like arms which may reach up to 60 cm in length on the largest specimens. Of all echinoderms, the Ophiuroidea may have the strongest tendency toward five-segment radial (pentaradial) symmetry. The body outline is similar to that of starfish, in that ophiuroids have five arms joined to a central body disk. However, in ophiuroids, the central body disk is sharply marked off from the arms. The disk contains all of the viscera. That is, the internal organs of digestion and reproduction never enter the arms, as they do in the Asteroidea. The underside of the disk contains the mouth, which has five toothed jaws formed from skeletal plates. The madreporite is usually located within one of the jaw plates, and not on the upper side of the animal as it is in starfish. The ophiuroid coelom is strongly reduced, particularly in comparison to other echinoderms. The vessels of the water vascular system end in tube feet. The water vascular system generally has one madreporite. Others, such as certain Euryalina or basket stars, have one per arm on the aboral surface. Still other forms have no madreporite at all. Suckers and ampullae are absent from the tube feet. Gas exchange and excretion occur through cilia-lined sacs called bursae; each opens between the arm bases on the underside of the disk. Typically ten bursae are found, and each fits between two stomach digestive pouches. Water flows through the bursae by means of cilia or muscular contraction. Oxygen is transported through the body by the hemal system, a series of sinuses and vessels distinct from the water vascular system.

Marine Arthropods

lobsterReef lobsters, Enoplometopus, are a genus of small lobsters that live on reefs in the Indo-Pacific, Caribbean and warmer parts of the east Atlantic Ocean. Species of Enoplometopus occur from coral reefs at depths of less than 1 meter to rocky reefs at depths of 300 meters. They are brightly colored, with stripes, rings, or spots. They are typically mainly red, orange, purplish and white. Reef lobsters are small, nocturnal (spending the day in caves or crevices), and very timid. The species can be distinguished by their coloration and morphology. Reef lobsters are distinguished from clawed lobsters (family Nephropidae) by having full chelae (claws) only on the first pair of pereiopods, the second and third pairs being only subchelate (where the last segment of the appendage can press against a short projection from the penultimate one). Clawed lobsters have full claws on the first three pereiopods. Males, unlike those of nephropoid lobsters, have an extra lobe on the second pleopod, which is assumed to have some function in reproduction. Reef lobsters have a shallow cervical groove while clawed lobsters have a deep cervical groove.

The Destruction of the Red Mangroves and the Tropical Coral Reefs

With global warming having a more pronounced effect on the world, all of the ecosystems are starting to die. Global warming causes the temperature of the water to rise and also the acidity of the water to rise. This is due to increased carbon dioxide levels in the atmosphere. As the ocean absorbs the carbon dioxide, carbonic acid is produced resulting in less calcium carbonate being available to shellfish and corals. For example, larval shellfish such as oysters can’t properly make their shell and they end up dying. The rising temperatures causes the delicate dinoflagellates that live inside the coral polyps to flee, seeking cooler water. When the dinoflagellates leave it takes the color out of the coral, this is called coral bleaching. Also with the acidity rising, the calcium carbonate “houses” around the polyps have started to disintegrate. These two issues have caused mass death of coral reefs world-wide. With the death of the coral reefs, more intense waves crash into the mangrove forests. This causes too much wave action and so destroys the habitats and also causes a greater amount of erosion to occur. The erosion causes the destruction of the trees and the surrounding habitats that the trees support and also harms humans with the rate of erosion. Besides the natural side of things destroying the trees and reefs, humans have their hand in it directly as well. Humans have ripped out whole forests of mangroves and replaced them with shrimp farms. 

But some people have started to help these ecosystems. Scientists are finding new ways to prevent the harmful effect of chemicals on the world and other people are trying to not use chemicals to preserve the ecosystems. When pesticides are used on plants the harmful chemicals are eventually washed into the ocean and destroy habitats and causes thousands of marine organisms to die. Because of this, scientists are attempting to get farmers to not use the pesticides and come up with new organic tools for the farmers to use on their crops. In an effort to save the mangrove forests, governments have established protected areas that humans are not to enter so that the trees will be safe. Also people help the trees by planting the seeds in other areas where they have a better chance to survive.

Works Cited

"FLMNH Ichthyology Department: South Florida Aquatic Environments." FLMNH Ichthyology Department: South Florida Aquatic Environments. Web. 13 Mar. 2015. < >.

"Global Warming and Mangroves - National Wildlife Federation." Global Warming and Mangroves - National Wildlife Federation. Web. 13 Mar. 2015. < >.

Kricher, John C. Tropical Ecology. Princeton, N.J.: Princeton UP, 2011. Print.

"Mangrove Ecosystems Life in the Mangrove Forest." Mangrove Ecosystems Life in the Mangrove Forest. 1 Jan. 2003. Web. 13 Mar. 2015. < >.

Sponsel, Leslie E. Tropical Deforestation: The Human Dimension. New York: Columbia UP, 1996. Print.

"Mangrove Morphology & Physiology." Mangrove Morphology & Physiology. Web. 3 June 2015. 

"Coral Identification: Types Of Coral (Part 1- Hard Coral)." Aquaviews SCUBA Blog. 8 June 2010. Web. 3 June 2015. 

"Coral Identification: Types Of Coral (Part 2- Soft Coral)." Aquaviews SCUBA Blog. 7 June 2010. Web. 3 June 2015. 

"MOLLUSCA." MOLLUSCA. Web. 3 June 2015. 

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