Portal:Marine_life

Portal:Marine life

A male whale shark at the Georgia Aquarium.

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Marine life, sea life, or ocean life is the plants, animals, and other organisms that live in the salt water of seas or oceans, or the brackish water of coastal estuaries. At a fundamental level, marine life affects the nature of the planet. Marine organisms, mostly microorganisms, produce oxygen and sequester carbon. Marine life, in part, shape and protect shorelines, and some marine organisms even help create new land (e.g. coral building reefs).

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...)

Marine biology is the scientific study of the biology of marine life, organisms in the sea. Given that in biology many phyla, families and genera have some species that live in the sea and others that live on land, marine biology classifies species based on the environment rather than on taxonomy. (Full article...)

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Entries here consist of Good and Featured articles, which meet a core set of high editorial standards.

Image 1

"Ctenophorae" (comb jelly)

Ctenophora (/təˈnɒfərə/; sg.: ctenophore /ˈtɛnəfɔːr, ˈtiːnə-/; from Ancient Greek κτείς (kteis) 'comb', and φέρω (pherō) 'to carry') comprise a phylum of marine invertebrates, commonly known as comb jellies, that inhabit sea waters worldwide. They are notable for the groups of cilia they use for swimming (commonly referred to as "combs"), and they are the largest animals to swim with the help of cilia.

Depending on the species, adult ctenophores range from a few millimeters to 1.5 m (5 ft) in size. Only 186 living species are currently recognised. (Full article...)
Image 2

A fin whale surfacing in Greenland

The fin whale (Balaenoptera physalus), also known as the finback whale or common rorqual, is a species of baleen whale and the second-longest cetacean after the blue whale. The biggest individual reportedly measured 26 m (85 ft) in length, with a maximum recorded weight of 77,000–81,000 kg (170,000–179,000 lb). The fin whale's body is long, slender and brownish-gray in color, with a paler underside to appear less conspicuous from below (countershading).

At least two recognized subspecies exist, one in the North Atlantic and one across the Southern Hemisphere. It is found in all the major oceans, from polar to tropical waters, though it is absent only from waters close to the pack ice at the poles and relatively small areas of water away from the open ocean. The highest population density occurs in temperate and cool waters. Its prey mainly consists of smaller schooling fish, small squid, or crustaceans, including copepods and krill. Mating takes place in temperate, low-latitude seas during the winter. Fin whales are often observed in pods of 6–10 animals, with whom they communicate utilizing frequency-modulated sounds, ranging from 16 to 40 hertz. (Full article...)
Image 3

Sei whale mother and calf

The sei whale (/seɪ/ SAY, Norwegian: [sæɪ]; Balaenoptera borealis) is a baleen whale. It is one of ten rorqual species, and the third-largest member after the blue and fin whales. They can grow up to 19.5 m (64 ft) in length and weigh as much as 28 t (28 long tons; 31 short tons). Two subspecies are recognized: B. b. borealis and B. b. schlegelii. The whale's ventral surface has sporadic markings ranging from light grey to white, and its body is usually dark steel grey in colour. It is among the fastest of all cetaceans, and can reach speeds of up to 50 km/h (31 mph) over short distances.

It inhabits most oceans and adjoining seas, and prefers deep offshore waters. It avoids polar and tropical waters and semi-enclosed bodies of water. The sei whale migrates annually from cool, subpolar waters in summer to temperate, subtropical waters in winter with a lifespan of 70 years. It is a filter feeder, with its diet consisting primarily of copepods, krill, and other zooplankton. It is typically solitary or can be found in groups numbering half a dozen. During the breeding period, a mating pair will remain together. Sei whale vocalizations usually lasts half a second, and occurs at 240–625 hertz. (Full article...)
Image 4

Palatal aspect of the skull from the type specimen

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...)
Image 5

The orca (Orcinus orca), or killer whale, is a toothed whale that is the largest member of the oceanic dolphin family. It is the only extant species in the genus Orcinus. Orcas are recognizable by their black-and-white patterned body. A cosmopolitan species, they are found in diverse marine environments, from Arctic to Antarctic regions to tropical seas.

Orcas are apex predators with a diverse diet. Individual populations often specialize in particular types of prey. This includes a variety of fish, sharks, rays, and marine mammals such as seals and other dolphins and whales. They are highly social; some populations are composed of highly stable matrilineal family groups (pods). Their sophisticated hunting techniques and vocal behaviors, often specific to a particular group and passed along from generation to generation are considered to be manifestations of animal culture. (Full article...)
Image 6
Cetacea is an infraorder that comprises the 94 species of whales, dolphins, and porpoises. It is divided into toothed whales (Odontoceti) and baleen whales (Mysticeti), which diverged from each other in the Eocene some 50 million years ago (mya). Cetaceans are descended from land-dwelling hoofed mammals, and the now extinct archaeocetes represent the several transitional phases from terrestrial to completely aquatic. Historically, cetaceans were thought to have descended from the wolf-like mesonychians, but cladistic analyses confirm their placement with even-toed ungulates in the order Cetartiodactyla.

Whale populations were drastically reduced in the 20th century from intensive whaling, and the activity was globally banned in 1982. Smaller cetaceans are at risk of accidentally getting caught by fishing vessels using, namely, seine fishing, drift netting, or gill netting operations. (Full article...)
Image 7

A coral outcrop on the Great Barrier Reef, Australia

Corals are colonial marine invertebrates within the class Anthozoa of the phylum Cnidaria. They typically form compact colonies of many identical individual polyps. Coral species include the important reef builders that inhabit tropical oceans and secrete calcium carbonate to form a hard skeleton.

A coral "group" is a colony of very many genetically identical polyps. Each polyp is a sac-like animal typically only a few millimeters in diameter and a few centimeters in height. A set of tentacles surround a central mouth opening. Each polyp excretes an exoskeleton near the base. Over many generations, the colony thus creates a skeleton characteristic of the species which can measure up to several meters in size. Individual colonies grow by asexual reproduction of polyps. Corals also breed sexually by spawning: polyps of the same species release gametes simultaneously overnight, often around a full moon. Fertilized eggs form planulae, a mobile early form of the coral polyp which, when mature, settles to form a new colony. (Full article...)
Image 8

A stove-pipe sponge

Sponges (also known as sea sponges), the members of the phylum Porifera (/pəˈrɪfərə/; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts.^{[excessive citations]} 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.

Sponges have unspecialized cells that can transform into other types and that often migrate between the main cell layers and the mesohyl in the process. Sponges do not have complex nervous, digestive or circulatory systems like humans. Instead, most rely on maintaining a constant water flow through their bodies to obtain food and oxygen and to remove wastes. Believed to be some of the most basal animals alive today, sponges were possibly the first to branch off the evolutionary tree from the last common ancestor of all animals, which would make them the sister group of all other animals. (Full article...)
Image 9

Bala shark, a bony fish

A fish (pl.: fish or fishes) is an aquatic, anamniotic, gill-bearing vertebrate animal with swimming fins and a hard skull, but lacking limbs with digits. Fish can be grouped into the more basal jawless fish and the more common jawed fish, the latter including all living cartilaginous and bony fish, as well as the extinct placoderms and acanthodians. Most fish are cold-blooded, their body temperature varying with the surrounding water, though some large active swimmers like white shark and tuna can hold a higher core temperature. Many fish can communicate acoustically with each other, such as during courtship displays.

The earliest fish appeared during the Cambrian as small filter feeders; they continued to evolve through the Paleozoic, diversifying into many forms. The earliest fish with dedicated respiratory gills and paired fins, the ostracoderms, had heavy bony plates that served as protective exoskeletons against invertebrate predators. The first fish with jaws, the placoderms, appeared in the Silurian and greatly diversified during the Devonian, the "Age of Fishes". (Full article...)
Image 10

The holotype and only specimen

Orcinus meyeri is a fossil species of Orcinus (killer whales) found in the Early Miocene deposits of southern Germany, known from two jaw fragments and 18 isolated teeth. It was originally described as Delphinus acutidens in 1859, but reclassified in 1873. Its validity is disputed, and it may be a synonymous with the ancient sperm whale Physeterula dubusi. It was found in the Alpine town of Stockach in the Molasse basin, which was a coastal area with strong tidal currents. (Full article...)

More recognized articles

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 family Architeuthidae. 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...)

List of selected articles

Image 1The European eel being critically endangered impacts other animals such as this Grey Heron that also eats eels. (from Marine conservation)
Image 2This timeline contains clickable links
Image 3Prochlorococcus, an influential bacterium which produces much of the world's oxygen (from Marine food web)
Image 4The range of sizes shown by prokaryotes (bacteria and archaea) and viruses relative to those of other organisms and biomolecules (from Marine prokaryotes)
Image 5Sponges have no nervous, digestive or circulatory system (from Marine invertebrates)
Image 6Phytoplankton (from Marine food web)
Image 7Earth's magnetic field (from Marine prokaryotes)
Image 8
Coastlines can be volatile habitats
(from Marine habitat)
Image 9Some lobe-finned fishes, like the extinct Tiktaalik, developed limb-like fins that could take them onto land (from Marine vertebrate)
Image 10Anthropogenic stressors to marine species threatened with extinction (from Marine food web)
Image 11Pennate diatom from an Arctic meltpond, infected with two chytrid-like [zoo-]sporangium fungal pathogens (in false-colour red). Scale bar = 10 µm. (from Marine fungi)
Image 12Chytrid 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 13
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 14Pelagibacter ubique of the SAR11 clade is the most abundant bacteria in the ocean and plays a major role in the global carbon cycle. (from Marine prokaryotes)
Image 15
Eukaryote versus prokaryote
(from Marine prokaryotes)
Image 16Reconstruction 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 17 Opabinia, an extinct stem group arthropod appeared in the Middle Cambrian (from Marine invertebrates)
Image 18 Kimberella, an early mollusc important for understanding the Cambrian explosion. Invertebrates are grouped into different phyla (body plans). (from Marine invertebrates)
Image 19Diatoms (from Marine food web)
Image 20The 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 21Marine protected areas are one area of legislation that helps marine ecosystems to thrive. (from Marine conservation)
Image 22Waves 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 23Mature forests have a lot of biomass invested in secondary growth which has low productivity (from Marine food web)
Image 24
Mudflat pollution
(from Marine habitat)
Image 25Sandy shores provide shifting homes to many species (from Marine habitat)
Image 26
Driftwood
(from Marine fungi)
Image 27Giant kelp is a foundation species for many kelp forests. (from Marine food web)
Image 28
Export processes in the Ocean from remote sensing
(from Marine prokaryotes)
Image 29
Generalized or hypothetical ancestral mollusc
(from Marine invertebrates)
Image 30Kelp forests provide habitat for many marine organisms (from Marine habitat)
Image 31Ocean 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 32Illegal, unreported and unregulated fishing (IUU) being prevented by a Japanese fisheries patrol. (from Marine conservation)
Image 33Halfbeak as larvae are one of the organisms adapted to the unique properties of the microlayer (from Marine habitat)
Image 34Sea spray containing marine microorganisms, including prokaryotes, can be swept high into the atmosphere where they become aeroplankton, and can travel the globe before falling back to earth. (from Marine prokaryotes)
Image 35Arrow worms are predatory components of plankton worldwide. (from Marine invertebrates)
Image 36An 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 37Sea 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 38Mangroves provide nurseries for fish (from Marine habitat)
Image 39Marine Species Changes in Latitude and Depth in three different ocean regions(1973-2019) (from Marine food web)
Image 40This 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 41Cyanobacteria blooms can contain lethal cyanotoxins (from Marine prokaryotes)
Image 42A protected sea turtle area that warns of fines and imprisonment on a beach in Miami, Florida. (from Marine conservation)
Image 43Coral reefs have a great amount of biodiversity. (from Marine conservation)
Image 44Oil spills have a significant impact on the marine environment such as this image from space of the Deepwater Horizon oil spill in the Gulf of Mexico. (from Marine conservation)
Image 45Reconstruction of Otavia antiqua, possibly the first animal about 760 million years ago (from Marine invertebrates)
Image 46Estuaries 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 47In 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 48
Lichen covered rocks
(from Marine fungi)
Image 49Predator fish sizing up schooling forage fish (from Marine food web)
Image 50The extinct Pteraspidomorphi, ancestral to jawed vertebrates (from Marine vertebrate)
Image 51
The global continental shelf, highlighted in light green, defines the extent of marine coastal habitats, and occupies 5% of the total world area
(from Marine habitat)
Image 52
Roles of fungi in the marine carbon cycle
Roles of fungi in the marine carbon cycle by processing phytoplankton-derived organic matter. Parasitic fungi, as well as saprotrophic fungi, directly assimilate phytoplankton organic carbon. By releasing zoospores, the fungi bridge the trophic linkage to zooplankton, known as the mycoloop. By modifying the particulate and dissolved organic carbon, they can affect bacteria and the microbial loop. These processes may modify marine snow chemical composition and the subsequent functioning of the biological carbon pump. (from Marine fungi)
Image 53Fishing down the food web (from Marine food web)
Image 54Only 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 55Topological positions versus mobility: (A) bottom-up groups (sessile and drifters), (B) groups at the top of the food web. Phyto, phytoplankton; MacroAlga, macroalgae; Proto, pelagic protozoa; Crus, Crustacea; PelBact, pelagic bacteria; Echino, Echinoderms; Amph, Amphipods; HerbFish, herbivorous fish; Zoopl, zooplankton; SuspFeed, suspension feeders; Polych, polychaetes; Mugil, Mugilidae; Gastropod, gastropods; Blenny, omnivorous blennies; Decapod, decapods; Dpunt, Diplodus puntazzo; Macropl, macroplankton; PlFish, planktivorous fish; Cephalopod, cephalopods; Mcarni, macrocarnivorous fish; Pisc, piscivorous fish; Bird, seabirds; InvFeed1 through InvFeed4, benthic invertebrate feeders. (from Marine food web)
Image 56Oceanic 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 57Elevation-area graph showing the proportion of land area at given heights and the proportion of ocean area at given depths (from Marine habitat)
Image 58The chloroplasts of glaucophytes have a peptidoglycan layer, evidence suggesting their endosymbiotic origin from cyanobacteria. (from Marine prokaryotes)
Image 59Fan mussel in a Mediterranean seagrass meadow (from Marine habitat)
Image 60
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 61Scanning 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 62
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 63Food 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)
Image 64Archaea 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)
Image 65Mudflats become temporary habitats for migrating birds (from Marine habitat)
Image 66Two Nanoarchaeum equitans cells with its larger host Ignicoccus (from Marine prokaryotes)
Image 67Antarctic 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 68The oligotrich ciliate has been characterised as the most important herbivore in the ocean (from Marine food web)
Image 69Hagfish are the only known living animals with a skull but no vertebral column. (from Marine vertebrate)
Image 70Ocean Conservation Namibia rescuing a seal that was entangled in discarded fishing nets. (from Marine conservation)
Image 71Pennate 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)
Image 72Halobacteria in salt evaporation ponds coloured purple by bacteriorhodopsin (from Marine prokaryotes)
Image 73Sea otter, classic keystone species which controls sea urchin numbers (from Marine vertebrate)
Image 74Schematic 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 75Phylogenetic and symbiogenetic tree of living organisms, showing a view of the origins of eukaryotes and prokaryotes (from Marine prokaryotes)
Image 76A food web is network of food chains, and as such can be represented graphically and analysed using techniques from network theory. (from Marine food web)
Image 77Ocean or marine biomass, in a reversal of terrestrial biomass, can increase at higher trophic levels. (from Marine food web)
Image 78
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 79Coral reefs provide marine habitats for tube sponges, which in turn become marine habitats for fishes (from Marine habitat)
Image 80 Dickinsonia may be the earliest animal. They appear in the fossil record 571 million to 541 million years ago. (from Marine invertebrates)
Image 81 Bloom of the filamentous cyanobacteria Trichodesmium (from Marine prokaryotes)
Image 82NOAA scuba diver surveying bleached corals. (from Marine conservation)
Image 83
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 84A 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 85Seep and vent interactions with surrounding deep-sea ecosystems. The y axis is meters above bottom on a log scale. DOC: dissolved organic carbon, POC: particulate organic carbon, SMS: seafloor massive sulfide. (from Marine food web)
Image 86The umbrella mouth gulper eel can swallow a fish much larger than itself (from Marine habitat)
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 88Conference events, such as the events hosted by the United Nations, help to bring together many stakeholders for awareness and action. (from Marine conservation)
Image 89
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
(from Marine prokaryotes)
Image 90Ocean particulate organic matter (POM) as imaged by a satellite in 2011 (from Marine food web)
Image 91Tidepools on rocky shores make turbulent habitats for many forms of marine life (from Marine habitat)
Image 92Phylogenetic and symbiogenetic tree of living organisms, showing a view of the origins of eukaryotes and prokaryotes (from Marine fungi)
Image 93Scale diagram of the layers of the pelagic zone (from Marine habitat)
Image 94Humpback whale straining krill (from Marine food web)
Image 95Technology such as this turtle excluder device (TED) allows this loggerhead sea turtle to escape. (from Marine conservation)
Image 96On 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 97Starfish larvae are bilaterally symmetric, whereas the adults have fivefold symmetry (from Marine invertebrates)
Image 98Common-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 99Diagram above contains clickable links
Image 100Biomass pyramids. Compared to terrestrial biomass pyramids, aquatic pyramids are generally inverted at the base. (from Marine food web)
Image 101"A variety of marine worms": plate from Das Meer by M.J. Schleiden (1804–1881) (from Marine invertebrates)
Image 102The deep sea amphipod Eurythenes plasticus, named after microplastics found in its body, demonstrating plastic pollution affects marine habitats even 6000m below sea level. (from Marine habitat)
Image 103Land runoff, pouring into the sea, can contain nutrients (from Marine habitat)
Image 104Some 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 105640 µm microplastic found in the deep sea amphipod Eurythenes plasticus (from Marine habitat)
Image 106Morphological diversity of fungi collected from a marine sponge species, Ircinia variabilis (from Marine fungi)
Image 107Cycling 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 108Bacterial flagellum rotated by a molecular motor at its base (from Marine prokaryotes)
Image 109Classic food web for grey seals in the Baltic Sea containing several typical marine food chains (from Marine food web)
Image 110The 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 111Phylogenetic 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 112Vibrio vulnificus, a virulent bacterium found in estuaries and along coastal areas (from Marine prokaryotes)
Image 113Ernst 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 114Salmon with fungal disease (from Marine fungi)
Image 115The 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 116Conceptual diagram of faunal community structure and food-web patterns along fluid-flux gradients within Guaymas seep and vent ecosystems. (from Marine food web)
Image 117The 49th plate from Ernst Haeckel's Kunstformen der Natur, 1904, showing various sea anemones classified as Actiniae, in the Cnidaria phylum (from Marine invertebrates)
Image 118Bryozoa, from Ernst Haeckel's Kunstformen der Natur, 1904 (from Marine invertebrates)
Image 119Lampreys are often parasitic and have a toothed, funnel-like sucking mouth (from Marine vertebrate)
Image 120Microplastics found in sediments on the seafloor (from Marine habitat)
Image 121Cryptic 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 122Whales were close to extinction until legislation was put in place. (from Marine conservation)
Image 123Cnidarians 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 124Dinoflagellate (from Marine food web)
Image 125A 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)

The following are images from various marine life-related articles on Wikipedia.

Image 1Lampreys are often parasitic and have a toothed, funnel-like sucking mouth (from Marine vertebrate)
Image 2Ecosystem services delivered by epibenthic bivalve 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)
Image 3Salt marshes (from Marine ecosystem)
Image 4In the fourth century BC, Aristotle gave accurate descriptions of the embryological development of the hound shark Mustelus mustelus. (from History of marine biology)
Image 5Lagoon (from Marine ecosystem)
Image 6Sea spray containing marine microorganisms can be swept high into the atmosphere, where it becomes part of the aeroplankton and may travel the globe before falling back to earth. (from Marine ecosystem)
Image 7Sea otter, classic keystone species which controls sea urchin numbers (from Marine vertebrate)
Image 8Coral reefs form complex marine ecosystems with tremendous biodiversity. (from Marine ecosystem)
Image 9Intertidal zones (from Marine ecosystem)
Image 10Coral reef (from Marine ecosystem)
Image 11Drivers of change in marine ecosystems (from Marine ecosystem)
Image 12Model of a Greek boat (from History of marine biology)
Image 13Some lobe-finned fishes, like the extinct Tiktaalik, developed limb-like fins that could take them onto land (from Marine vertebrate)
Image 14Hagfish are the only known living animals with a skull but no vertebral column. (from Marine vertebrate)
Image 15Global distribution of coral, mangrove, and seagrass diversity (from Marine ecosystem)
Image 16The extinct Pteraspidomorphi, ancestral to jawed vertebrates (from Marine vertebrate)
Image 17Kelp forest (from Marine ecosystem)
Image 18Global map of large marine ecosystems. Oceanographers and biologists have identified 66 LMEs worldwide. (from Marine ecosystem)
Image 19The voyage of the Beagle (from History of marine biology)
Image 20Estuaries (from Marine ecosystem)
Image 21
HMS Challenger during its pioneer expedition of 1872–76
(from History of marine biology)
Image 22A science ROV being retrieved by an oceanographic research vessel. (from History of marine biology)
Image 23Seagrass meadow (from Marine ecosystem)
Image 24Mangrove forests (from Marine ecosystem)
Image 25General characteristics of a large marine ecosystem (Gulf of Alaska) (from Marine ecosystem)

... that The Inland Whale, by Theodora Kroeber, sought to demonstrate the literary merit of Indigenous American oral traditions?
... that in the lead-up to the Second World War, the British government stockpiled more than 100,000 tons of whale oil?
... that one can swim with humpback whales in the Niue Nukutuluea Multiple-Use Marine Park?
... that for 25 years after an attempt to explode a whale went awry, the Oregon TV station that filmed it regularly fielded requests for its footage?
... that Bayfront MRT station in Singapore has public art that features ships powered by whales and dragons, hand-drawn by children?
... that when watercress algae grows on degraded coral reefs, coral larvae settle on the seaweed as readily as they do on the rubble substrate?

... the Sperm Whale, at 18 metres long, is the largest toothed animal to have ever lived.
... Migaloo is an albino Humpback Whale often spotted off the east coast of Australia.
... As a way to put off attackers (or to remove indigestible stomach content), sharks can turn their stomachs inside out and vomit up their latest meal. Some predators eat the vomit instead of the shark.
... in spite of their enormous mass, baleen whales are capable of leaping completely out of the water, particularly the Humpback Whale.
... the Orca, is the fastest swimmer of all the cetaceans and can reach speeds of more than 50km/h while hunting.
... Some sharks, if inverted, enter a natural state of temporary paralysis called tonic immobility. Researchers use this condition for handling sharks safely.

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Major Fields of Marine Biology: Marine Biology - Ecology - Zoology - Animal Taxonomy
Specific Fields of Marine Biology:Herpetology - Ichthyology - Planktology - Ornithology
Biologists:Zoologists - Algologists - Malacologists - Conchologists - Biologists - Marine Biologists - Anatomists - Botanists - Ecologists - Ichthyologists
Organisms:

Plants: Algae - Brown Algae - Green Algae - Red Algae - Edible seaweeds -
Invertebrates:Cnidarians - Echinoderms - Molluscs - Bivalves - Cephalopods - Gastropods
Fish: Fish - Bony fish - Lobe-finned fish - Ray-finned fish - Cartilaginous fish - Electric fish - Fish diseases - Rays - Sharks - Extinct fish - Fictional fish - Fisheries science - Fishing - Fishkeeping - Live-bearing fish
Reptiles and Amphibians: Marine reptiles - Sea turtles - Mosasaurs - Sauropterygians
Mammals: Marine mammals - Cetaceans - Pinnipeds - Sirenians

Misc.: Aquariums - Oceanaria - Agnatha - Endangered species - Aquatic biomes - Biogeographic realms - Aquatic organisms - Cyanobacteria - Dinoflaggellates

Cuttlefish use camouflage to hide from predators.

Photo credit: Raul654

Cuttlefish are sometimes called the chameleon of the sea because of their remarkable ability to rapidly alter their skin colour at will. Their skin flashes a fast-changing pattern as communication to other cuttlefish and to camouflage them from predators.

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