Marine invertebrates exhibit a wide range of modifications to survive in poorly oxygenated waters, including breathing tubes as in mollusc siphons. Fish have gills instead of lungs, although some species of fish, such as the lungfish, have both. Marine mammals (e.g. dolphins, whales, otters, and seals) need to surface periodically to breathe air. (Full article...)
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The deep biosphere is the part of the biosphere that resides below the first few meters of the surface. It extends down at least 5 kilometers below the continental surface and 10.5 kilometers below the sea surface, at temperatures that may reach beyond 120 °C (248 °F) which is comparable to the maximum temperature where a metabolically active organism has been found. It includes all three domains of life and the genetic diversity rivals that on the surface.
The first indications of deep life came from studies of oil fields in the 1920s, but it was not certain that the organisms were indigenous until methods were developed in the 1980s to prevent contamination from the surface. Samples are now collected in deep mines and scientific drilling programs in the ocean and on land. Deep observatories have been established for more extended studies. (Full article...)
The sea mink (Neogale macrodon) is a recently extinct species of mink that lived on the eastern coast of North America around the Gulf of Maine on the New England seaboard. It was most closely related to the American mink (Neogale vison), with continuing debate about whether or not the sea mink should be considered a subspecies of the American mink (as Neogale vison macrodon) or a species of its own. The main justification for a separate species designation is the size difference between the two minks, but other distinctions have been made, such as its redder fur. The only known remains are bone fragments unearthed in Native American shell middens. Its actual size is speculative, based largely on tooth remains.
The sea mink was first described in 1903, after its extinction; information regarding its external appearance and habits stem from speculation and from accounts made by fur traders and Native Americans. It may have exhibited behavior similar to the American mink, in that it probably maintained home ranges, was polygynandrous, and had a similar diet, though more seaward-oriented. It was probably found on the New England coast and the Maritime Provinces, though its range may have stretched further south during the last glacial period. Conversely, its range may have been restricted solely to the New England coast, specifically the Gulf of Maine, or just to the nearby islands. The largest of the minks, the sea mink was more desirable to fur traders and became extinct in the late 19th or early 20th century. (Full article...)
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X. bocki. Black arrow indicates side furrow. a is the anterior tip. p is the posterior tip. Black triangle indicates mouth. White triangle indicates circumferential furrow. The scale bar in the bottom right is 1 cm.
Xenoturbella bocki is a marine benthicworm-like species from the genus Xenoturbella. It is found in saltwater sea floor habitats off the coast of Europe, predominantly Sweden. It was the first species in the genus discovered. Initially it was collected by Swedish zoologist Sixten Bock in 1915, and described in 1949 by Swedish zoologist Einar Westblad. The unusual digestive structure of this species, in which a single opening is used to eat food and excrete waste, has led to considerable study and controversy as to its classification. It is a bottom-dwelling, burrowing carnivore that eats mollusks (likely larval forms, as opposed to hard-shelled adults). (Full article...)
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Five pinniped species, clockwise from top left: New Zealand fur seal (Arctocephalus forsteri), southern elephant seal (Mirounga leonina), Steller sea lion (Eumetopias jubatus), walrus (Odobenus rosmarus), and grey seal (Halichoerus grypus) Pinnipedia is an infraorder of mammals in the orderCarnivora, composed of seals, sea lions, and the walrus. A member of this group is called a pinniped or a seal. They are widespread throughout the ocean and some larger lakes, primarily in colder waters. Pinnipeds range in size from the 1.1 m (3 ft 7 in) and 50 kg (110 lb) Baikal seal to the 6 m (20 ft) and 3,700 kg (8,200 lb) male southern elephant seal, which is also the largest member of Carnivora. Several species exhibit sexual dimorphism, such as the southern elephant seal, where the males can be more than three times as long and six times as massive as the females, or the Ross seal, which has females typically larger than the males. Four seal species are estimated to have over one million members, while six are classified as endangered with population counts as low as 600, and two, the Caribbean monk seal and the Japanese sea lion, went extinct in the 20th century.
The 34 extant species of Pinnipedia are split into 22 genera within 3 families: Odobenidae, comprising the walrus; Otariidae, the eared seals, split between the sea lions and fur seals; and Phocidae, the earless or true seals. Odobenidae and Otariidae are combined into the superfamilyOtarioidea, with Phocidae in Phocoidea. Extinct species have also been placed into the three extant families, as well as the extinct family Desmatophocidae, though most extinct species have not been categorized into a subfamily. Nearly one hundred extinct Pinnipedia species have been discovered, though due to ongoing research and discoveries the exact number and categorization is not fixed. (Full article...)
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The silky shark (Carcharhinus falciformis), also known by numerous names such as blackspot shark, gray whaler shark, olive shark, ridgeback shark, sickle shark, sickle-shaped shark and sickle silk shark, is a species of requiem shark, in the familyCarcharhinidae, named for the smooth texture of its skin. It is one of the most abundant sharks in the pelagic zone, and can be found around the world in tropical waters. Highly mobile and migratory, this shark is most often found over the edge of the continental shelf down to 50 m (164 ft). The silky shark has a slender, streamlined body and typically grows to a length of 2.5 m (8 ft 2 in). It can be distinguished from other large requiem sharks by its relatively small first dorsal fin with a curving rear margin, its tiny second dorsal fin with a long free rear tip, and its long, sickle-shaped pectoral fins. It is a deep, metallic bronze-gray above and white below.
With prey often scarce in its oceanic environment, the silky shark is a swift, inquisitive, and persistent hunter. It feeds mainly on bony fishes and cephalopods, and has been known to drive them into compacted schools before launching open-mouthed, slashing attacks. This species often trails schools of tuna, a favored prey. Its sense of hearing is extremely acute, allowing it to localize the low-frequency noises generated by other feeding animals, and, by extension, sources of food. The silky shark is viviparous, meaning that the developing embryos are sustained by a placental connection to their mother. Significant geographical variation is seen in its life history details. Reproduction occurs year-round except in the Gulf of Mexico, where it follows a seasonal cycle. Females give birth to litters of up to 16 pups annually or biennially. The newborn sharks spend their first months in relatively sheltered reef nurseries on the outer continental shelf, growing substantially before moving into the open ocean. (Full article...)
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Crinoid on the reef of Batu Moncho Island, Indonesia
Crinoids are marine invertebrates that make up the classCrinoidea. Crinoids that are attached to the sea bottom by a stalk in their juvenile form are commonly called sea lilies, while the unstalked forms, called feather stars or comatulids, are members of the largest crinoid order, Comatulida. Crinoids are echinoderms in the phylumEchinodermata, which also includes the starfish, brittle stars, sea urchins and sea cucumbers. They live in both shallow water and in depths as great as 9,000 meters (30,000 ft).
Adult crinoids are characterised by having the mouth located on the upper surface. This is surrounded by feeding arms, and is linked to a U-shaped gut, with the anus being located on the oral disc near the mouth. Although the basic echinoderm pattern of fivefold symmetry can be recognised, in most crinoids the five arms are subdivided into ten or more. These have feathery pinnules and are spread wide to gather planktonic particles from the water. At some stage in their lives, most crinoids have a short stem used to attach themselves to the substrate, but many live attached only as juveniles and become free-swimming as adults. (Full article...)
Archelon is an extinct marine turtle from the Late Cretaceous, and is the largest turtle ever to have been documented, with the biggest specimen measuring 4.6 m (15 ft) from head to tail and 2.2–3.2 t (2.4–3.5 short tons) in body mass. It is known only from the Pierre Shale and has one species, A. ischyros. In the past, the genus also contained A. marshii and A. copei, though these have been reassigned to Protostega and Kansastega, respectively. The genus was named in 1895 by American paleontologist George Reber Wieland based on a skeleton from South Dakota, who placed it into the extinct familyProtostegidae. The leatherback sea turtle (Dermochelys coriacea) was once thought to be its closest living relative, but now, Protostegidae is thought to be a completely separate lineage from any living sea turtle.
Archelon had a leathery carapace instead of the hard shell seen in most sea turtles. The carapace may have featured a row of small ridges, each peaking at 2.5 or 5 cm (1 or 2 in) in height. It had an especially hooked beak and its jaws were adept at crushing, so it probably ate hard-shelled crustaceans, mollusks, and possibly even sponges, while slowly moving over the seafloor. It also potentially consumed other animals, whilst swimming closer to the surface, like jellyfish, squid, or nautiloids. However, its beak may have been better-adapted for shearing flesh, with fish being another possible prey choice. With its large and strong foreflippers, Archelon was likely able to produce powerful strokes necessary for open-ocean travel and, if need be, escape from fellow marine predators. It inhabited the northern Western Interior Seaway, a mild to cool temperate area, dominated by plesiosaurs, hesperornithiform seabirds, and mosasaurs. It may have gone extinct due to the shrinking of the seaway, increased infant mortality rates (in the sea), higher instances of egg and hatchling predation (on land), and a rapidly cooling climate. (Full article...)
Steller's sea cow (Hydrodamalis gigas) is an extinctsirenian described by Georg Wilhelm Steller in 1741. At that time, it was found only around the Commander Islands in the Bering Sea between Alaska and Russia; its range extended across the North Pacific during the Pleistoceneepoch, and likely contracted to such an extreme degree due to the glacial cycle. It is possible indigenous populations interacted with the animal before Europeans. Steller first encountered it on Vitus Bering's Great Northern Expedition when the crew became shipwrecked on Bering Island. Much of what is known about its behavior comes from Steller's observations on the island, documented in his posthumous publication On the Beasts of the Sea. Within 27 years of its discovery by Europeans, the slow-moving and easily-caught mammal was hunted into extinction for its meat, fat, and hide.
Some 18th-century adults would have reached weights of 8–10 t (8.8–11.0 short tons) and lengths up to 9 m (30 ft). It was a member of the family Dugongidae, of which the 3 m (9.8 ft) long dugong (Dugong dugon) is the sole living member. It had a thicker layer of blubber than other members of the order, an adaptation to the cold waters of its environment. Its tail was forked, like that of whales or dugongs. Lacking true teeth, it had an array of white bristles on its upper lip and two keratinous plates within its mouth for chewing. It fed mainly on kelp, and communicated with sighs and snorting sounds. Steller believed it was a monogamous and social animal living in small family groups and raising its young, similar to modern sirenians. (Full article...)
A corallivore is an animal that feeds on coral. Corallivores are an important group of reef organism because they can influence coral abundance, distribution, and community structure. Corallivores feed on coral using a variety of unique adaptations and strategies. Known corallivores include certain mollusks, annelids, fish, crustaceans, flatworms and echinoderms. The first recorded evidence of corallivory was presented by Charles Darwin in 1842 during his voyage on HMS Beagle in which he found coral in the stomach of two Scarusparrotfish. (Full article...)
Giant squid, Architeuthis sp., modified from an illustration by A. E. Verrill, 1880
The giant squid (Architeuthis dux) is a species of deep-ocean dwelling squid in the familyArchiteuthidae. It can grow to a tremendous size, offering an example of abyssal gigantism: recent estimates put the maximum size at around 12–13 m (39–43 ft) for females and 10 m (33 ft) for males, from the posterior fins to the tip of the two long tentacles (longer than the colossal squid at an estimated 9–10 m (30–33 ft), but substantially lighter, as the tentacles make up most of the length). The mantle of the giant squid is about 2 m (6 ft 7 in) long (more for females, less for males), and the length of the squid excluding its tentacles (but including head and arms) rarely exceeds 5 m (16 ft). Claims of specimens measuring 20 m (66 ft) or more have not been scientifically documented.
The number of different giant squid species has been debated, but genetic research suggests that only one species exists. (Full article...)
Image 5Cnidarians are the simplest animals with cells organised into tissues. Yet the starlet sea anemone contains the same genes as those that form the vertebrate head. (from Marine invertebrates)
Image 6Chytrid parasites of marine diatoms. (A) Chytrid sporangia on Pleurosigma sp. The white arrow indicates the operculate discharge pore. (B) Rhizoids (white arrow) extending into diatom host. (C) Chlorophyll aggregates localized to infection sites (white arrows). (D and E) Single hosts bearing multiple zoosporangia at different stages of development. The white arrow in panel E highlights branching rhizoids. (F) Endobiotic chytrid-like sporangia within diatom frustule. Bars = 10 μm. (from Marine fungi)
Image 7Coral reefs provide marine habitats for tube sponges, which in turn become marine habitats for fishes (from Marine habitat)
Image 9Reconstruction of an ammonite, a highly successful early cephalopod that first appeared in the Devonian (about 400 mya). They became extinct during the same extinction event that killed the land dinosaurs (about 66 mya). (from Marine invertebrates)
Image 10Microplastics found in sediments on the seafloor (from Marine habitat)
Image 11Oceanic pelagic food web showing energy flow from micronekton to top predators. Line thickness is scaled to the proportion in the diet. (from Marine food web)
Image 12Whales were close to extinction until legislation was put in place. (from Marine conservation)
Image 15The distribution of anthropogenic stressors faced by marine species threatened with extinction in various marine regions of the world. Numbers in the pie charts indicate the percentage contribution of an anthropogenic stressors’ impact in a specific marine region. (from Marine food web)
Image 21Ernst Haeckel's 96th plate, showing some marine invertebrates. Marine invertebrates have a large variety of body plans, which are currently categorised into over 30 phyla. (from Marine invertebrates)
Image 22Common-enemy graph of Antarctic food web. Potter Cove 2018. Nodes represent basal species and links indirect interactions (shared predators). Node and link widths are proportional to number of shared predators. Node colors represent functional groups. (from Marine food web)
Image 23Food web structure in the euphotic zone. The linear food chain large phytoplankton-herbivore-predator (on the left with red arrow connections) has fewer levels than one with small phytoplankton at the base. The microbial loop refers to the flow from the dissolved organic carbon (DOC) via heterotrophic bacteria (Het. Bac.) and microzooplankton to predatory zooplankton (on the right with black solid arrows). Viruses play a major role in the mortality of phytoplankton and heterotrophic bacteria, and recycle organic carbon back to the DOC pool. Other sources of dissolved organic carbon (also dashed black arrows) includes exudation, sloppy feeding, etc. Particulate detritus pools and fluxes are not shown for simplicity. (from Marine food web)
Mycoloop links between phytoplankton and zooplankton
Chytrid‐mediated trophic links between phytoplankton and zooplankton (mycoloop). While small phytoplankton species can be grazed upon by zooplankton, large phytoplankton species constitute poorly edible or even inedible prey. Chytrid infections on large phytoplankton can induce changes in palatability, as a result of host aggregation (reduced edibility) or mechanistic fragmentation of cells or filaments (increased palatability). First, chytrid parasites extract and repack nutrients and energy from their hosts in form of readily edible zoospores. Second, infected and fragmented hosts including attached sporangia can also be ingested by grazers (i.e. concomitant predation). (from Marine fungi)
Image 28Ocean Conservation Namibia rescuing a seal that was entangled in discarded fishing nets. (from Marine conservation)
Image 35Archaea were initially viewed as extremophiles living in harsh environments, such as the yellow archaea pictured here in a hot spring, but they have since been found in a much broader range of habitats. (from Marine prokaryotes)
Model of the energy generating mechanism in marine bacteria
(1) When sunlight strikes a rhodopsin molecule (2) it changes its configuration so a proton is expelled from the cell (3) the chemical potential causes the proton to flow back to the cell (4) thus generating energy (5) in the form of adenosine triphosphate. (from Marine prokaryotes)
Image 43Some representative ocean animal life (not drawn to scale) within their approximate depth-defined ecological habitats. Marine microorganisms exist on the surfaces and within the tissues and organs of the diverse life inhabiting the ocean, across all ocean habitats. (from Marine habitat)
Image 59The deep sea amphipodEurythenes plasticus, named after microplastics found in its body, demonstrating plastic pollution affects marine habitats even 6000m below sea level. (from Marine habitat)
Image 61On average there are more than one million microbial cells in every drop of seawater, and their collective metabolisms not only recycle nutrients that can then be used by larger organisms but also catalyze key chemical transformations that maintain Earth’s habitability. (from Marine food web)
Image 62This algae bloom occupies sunlit epipelagic waters off the southern coast of England. The algae are maybe feeding on nutrients from land runoff or upwellings at the edge of the continental shelf. (from Marine habitat)
Image 63Dickinsonia may be the earliest animal. They appear in the fossil record 571 million to 541 million years ago. (from Marine invertebrates)
Image 66The pelagic food web, showing the central involvement of marine microorganisms in how the ocean imports nutrients from and then exports them back to the atmosphere and ocean floor (from Marine food web)
Image 67Cryptic interactions in the marine food web. Red: mixotrophy; green: ontogenetic and species differences; purple: microbial cross‐feeding; orange: auxotrophy; blue: cellular carbon partitioning. (from Marine food web)
Image 68Anthropogenic stressors to marine species threatened with extinction (from Marine food web)
Image 69Ocean or marine biomass, in a reversal of terrestrial biomass, can increase at higher trophic levels. (from Marine food web)
Image 76Schematic representation of the changes in abundance between trophic groups in a temperate rocky reef ecosystem. (a) Interactions at equilibrium. (b) Trophic cascade following disturbance. In this case, the otter is the dominant predator and the macroalgae are kelp. Arrows with positive (green, +) signs indicate positive effects on abundance while those with negative (red, -) indicate negative effects on abundance. The size of the bubbles represents the change in population abundance and associated altered interaction strength following disturbance. (from Marine food web)
Image 77
Estimates of microbial species counts in the three domains of life
Bacteria are the oldest and most biodiverse group, followed by Archaea and Fungi (the most recent groups). In 1998, before awareness of the extent of microbial life had gotten underway, Robert M. May estimated there were 3 million species of living organisms on the planet. But in 2016, Locey and Lennon estimated the number of microorganism species could be as high as 1 trillion. (from Marine prokaryotes)
Image 79Conceptual diagram of faunal community structure and food-web patterns along fluid-flux gradients within Guaymas seep and vent ecosystems. (from Marine food web)
Image 80Estuaries occur when rivers flow into a coastal bay or inlet. They are nutrient rich and have a transition zone which moves from freshwater to saltwater. (from Marine habitat)
Image 81In the open ocean, sunlit surface epipelagic waters get enough light for photosynthesis, but there are often not enough nutrients. As a result, large areas contain little life apart from migrating animals. (from Marine habitat)
Image 82Ocean surface chlorophyll concentrations in October 2019. The concentration of chlorophyll can be used as a proxy to indicate how many phytoplankton are present. Thus on this global map green indicates where a lot of phytoplankton are present, while blue indicates where few phytoplankton are present. – NASA Earth Observatory 2019. (from Marine food web)
Image 84Halfbeak as larvae are one of the organisms adapted to the unique properties of the microlayer (from Marine habitat)
Image 85Phylogenetic and symbiogenetic tree of living organisms, showing a view of the origins of eukaryotes and prokaryotes (from Marine fungi)
Image 86Marine Species Changes in Latitude and Depth in three different ocean regions(1973-2019) (from Marine food web)
Image 87Jellyfish are easy to capture and digest and may be more important as food sources than was previously thought. (from Marine food web)
Image 88
Different bacteria shapes (cocci, rods and spirochetes) and their sizes compared with the width of a human hair. A few bacteria are comma-shaped (vibrio). Archaea have similar shapes, though the archaeon Haloquadratum is flat and square.
The unit μm is a measurement of length, the micrometer, equal to 1/1,000 of a millimeter
Image 89A 2016 metagenomic representation of the tree of life using ribosomal protein sequences. The tree includes 92 named bacterial phyla, 26 archaeal phyla and five eukaryotic supergroups. Major lineages are assigned arbitrary colours and named in italics with well-characterized lineage names. Lineages lacking an isolated representative are highlighted with non-italicized names and red dots. (from Marine prokaryotes)
Image 92A microbial mat encrusted with iron oxide on the flank of a seamount can harbour microbial communities dominated by the iron-oxidizing Zetaproteobacteria (from Marine prokaryotes)
Image 94Sandy shores provide shifting homes to many species (from Marine habitat)
Image 95Conference events, such as the events hosted by the United Nations, help to bring together many stakeholders for awareness and action. (from Marine conservation)
Image 96A protected sea turtle area that warns of fines and imprisonment on a beach in Miami, Florida. (from Marine conservation)
Image 97Some lobe-finned fishes, like the extinct Tiktaalik, developed limb-like fins that could take them onto land (from Marine vertebrate)
Image 101Waves and currents shape the intertidal shoreline, eroding the softer rocks and transporting and grading loose particles into shingles, sand or mud (from Marine habitat)
Image 102640 µm microplastic found in the deep sea amphipod Eurythenes plasticus (from Marine habitat)
Image 103
Bacterioplankton and the pelagic marine food web
Solar radiation can have positive (+) or negative (−) effects resulting in increases or decreases in the heterotrophic activity of bacterioplankton. (from Marine prokaryotes)
Image 104Only 29 percent of the world surface is land. The rest is ocean, home to the marine habitats. The oceans are nearly four kilometres deep on average and are fringed with coastlines that run for nearly 380,000 kilometres.
Image 109Antarctic marine food web. Potter Cove 2018. Vertical position indicates trophic level and node widths are proportional to total degree (in and out). Node colors represent functional groups. (from Marine food web)
Image 110
Diagram of a mycoloop (fungus loop)
Parasitic chytrids can transfer material from large inedible phytoplankton to zooplankton. Chytrids zoospores are excellent food for zooplankton in terms of size (2–5 μm in diameter), shape, nutritional quality (rich in polyunsaturated fatty acids and cholesterols). Large colonies of host phytoplankton may also be fragmented by chytrid infections and become edible to zooplankton. (from Marine fungi)
Image 112Phylogenetic tree representing bacterial OTUs from clone libraries and next-generation sequencing. OTUs from next-generation sequencing are displayed if the OTU contained more than two sequences in the unrarefied OTU table (3626 OTUs). (from Marine prokaryotes)
Image 113An in situ perspective of a deep pelagic food web derived from ROV-based observations of feeding, as represented by 20 broad taxonomic groupings. The linkages between predator to prey are coloured according to predator group origin, and loops indicate within-group feeding. The thickness of the lines or edges connecting food web components is scaled to the log of the number of unique ROV feeding observations across the years 1991–2016 between the two groups of animals. The different groups have eight colour-coded types according to main animal types as indicated by the legend and defined here: red, cephalopods; orange, crustaceans; light green, fish; dark green, medusa; purple, siphonophores; blue, ctenophores and grey, all other animals. In this plot, the vertical axis does not correspond to trophic level, because this metric is not readily estimated for all members. (from Marine food web)
Image 114The Ocean Cleanup is one of many organizations working toward marine conservation such at this interceptor vessel that prevents plastic from entering the ocean. (from Marine conservation)
Image 120Elevation-area graph showing the proportion of land area at given heights and the proportion of ocean area at given depths (from Marine habitat)
Image 121Sponges have no nervous, digestive or circulatory system (from Marine invertebrates)
Image 122Scanning electron micrograph of a strain of Roseobacter, a widespread and important genus of marine bacteria. For scale, the membrane pore size is 0.2 μm in diameter. (from Marine prokaryotes)
Image 123Cycling of marine phytoplankton. Phytoplankton live in the photic zone of the ocean, where photosynthesis is possible. During photosynthesis, they assimilate carbon dioxide and release oxygen. If solar radiation is too high, phytoplankton may fall victim to photodegradation. For growth, phytoplankton cells depend on nutrients, which enter the ocean by rivers, continental weathering, and glacial ice meltwater on the poles. Phytoplankton release dissolved organic carbon (DOC) into the ocean. Since phytoplankton are the basis of marine food webs, they serve as prey for zooplankton, fish larvae and other heterotrophic organisms. They can also be degraded by bacteria or by viral lysis. Although some phytoplankton cells, such as dinoflagellates, are able to migrate vertically, they are still incapable of actively moving against currents, so they slowly sink and ultimately fertilize the seafloor with dead cells and detritus. (from Marine food web)
Image 124Sea ice food web and the microbial loop. AAnP = aerobic anaerobic phototroph, DOC = dissolved organic carbon, DOM = dissolved organic matter, POC = particulate organic carbon, PR = proteorhodopsins. (from Marine food web)
Image 22Ecosystem services delivered by epibenthicbivalve reefs. Reefs provide coastal protection through erosion control and shoreline stabilization, and modify the physical landscape by ecosystem engineering, thereby providing habitat for species by facilitative interactions with other habitats such as tidal flat benthic communities, seagrasses and marshes. (from Marine ecosystem)
... The insides of the sharksintestines are spiral shaped. Because of this, some sharks have spiral-shaped droppings.
... Even though the basking shark is considered to be slow and very large, it can actually breach the water, i.e. jump fully out, as some whales do.
... because whales and dolphins are streamlined to swim in water, they do not have external organs. This makes it almost impossible to tell the sex of a whale or dolphin when watching them on the sea surface.
... dolphins often leap clear of the water when travelling at speed. This is because the density of water is much greater than that of air and they are able to travel faster by leaping out of the water.
... in spite of their enormous mass, baleen whales are capable of leaping completely out of the water, particularly the Humpback Whale.
... Shark skin is so rough that in the past it was used to make a type of sandpaper, called shagreen.
The Magellanic penguin (Spheniscus magellanicus) is a South American penguin, breeding in coastal Argentina, Chile and the Falkland Islands, with some migrating to Brazil. It is the most numerous of the Spheniscus penguins. Its nearest relatives are the African Penguin, the Humboldt Penguin and the Galápagos Penguin.
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![Image 29Pennate diatom from an Arctic meltpond, infected with two chytrid-like [zoo-]sporangium fungal pathogens (in false-colour red). Scale bar = 10 µm. (from Marine food web)](/wiki/File:Pennate_diatom_infected_with_two_chytrid-like_fungal_pathogens.png)
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