Portal:Marine life

The Marine Life Portal Killer whales (orcas) are highly visible marine apex predators that hunt many large species. But most biological activity in the ocean takes place with microscopic marine organisms that cannot be seen individually with the naked eye, such as marine bacteria and phytoplankton. 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...) Recognized content - Entries here consist of Good and Featured articles, which meet a core set of high editorial standards. The dusky dolphin (Lagenorhynchus obscurus) is a dolphin found in coastal waters in the Southern Hemisphere. Its specific epithet is Latin for "dark" or "dim". It is very closely genetically related to the Pacific white-sided dolphin, but current scientific consensus holds they are distinct species. The dolphin's range is patchy, with major populations around South America, southwestern Africa, New Zealand, and various oceanic islands, with some sightings around southern Australia and Tasmania. The dusky dolphin prefers cool currents and inshore waters, but can also be found offshore. It feeds on a variety of fish and squid species and has flexible hunting tactics. The dusky dolphin is known for its remarkable acrobatics, having a number of aerial behaviours. The status of the dolphin is unknown, but it has been commonly caught in gill nets. (Full article...) "Acephala", from Ernst Haeckel's Kunstformen der Natur (1904) Bivalvia (/baɪˈvælviə/), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bivalves have no head and they lack some usual molluscan organs, like the radula and the odontophore. The class includes the clams, oysters, cockles, mussels, scallops, and numerous other families that live in saltwater, as well as a number of families that live in freshwater. The majority are filter feeders. The gills have evolved into ctenidia, specialised organs for feeding and breathing. Most bivalves bury themselves in sediment, where they are relatively safe from predation. Others lie on the sea floor or attach themselves to rocks or other hard surfaces. Some bivalves, such as the scallops and file shells, can swim. The shipworms bore into wood, clay, or stone and live inside these substances. The shell of a bivalve is composed of calcium carbonate, and consists of two, usually similar, parts called valves. These are joined together along one edge (the hinge line) by a flexible ligament that, usually in conjunction with interlocking "teeth" on each of the valves, forms the hinge. This arrangement allows the shell to be opened and closed without the two halves detaching. The shell is typically bilaterally symmetrical, with the hinge lying in the sagittal plane. Adult shell sizes of bivalves vary from fractions of a millimetre to over a metre in length, but the majority of species do not exceed 10 cm (4 in). (Full article...) Caribbean reef squid (Sepioteuthis sepioidea) True squid are molluscs with an elongated soft body, large eyes, eight arms, and two tentacles in the superorder Decapodiformes, though many other molluscs within the broader Neocoleoidea are also called squid despite not strictly fitting these criteria. Like all other cephalopods, squid have a distinct head, bilateral symmetry, and a mantle. They are mainly soft-bodied, like octopuses, but have a small internal skeleton in the form of a rod-like gladius or pen, made of chitin. Squid diverged from other cephalopods during the Jurassic and occupy a similar role to teleost fish as open water predators of similar size and behaviour. They play an important role in the open water food web. The two long tentacles are used to grab prey and the eight arms to hold and control it. The beak then cuts the food into suitable size chunks for swallowing. Squid are rapid swimmers, moving by jet propulsion, and largely locate their prey by sight. They are among the most intelligent of invertebrates, with groups of Humboldt squid having been observed hunting cooperatively. They are preyed on by sharks, other fish, sea birds, seals and cetaceans, particularly sperm whales. (Full article...) The pigeye shark or Java shark (Carcharhinus amboinensis) is an uncommon species of requiem shark, in the family Carcharhinidae, found in the warm coastal waters of the eastern Atlantic and western Indo-Pacific. It prefers shallow, murky environments with soft bottoms, and tends to roam within a fairly localised area. With its bulky grey body, small eyes, and short, blunt snout, the pigeye shark looks almost identical to (and is often confused with) the better-known bull shark (C. leucas). The two species differ in vertebral count, the relative sizes of the dorsal fins, and other subtle traits. This shark typically reaches lengths of 1.9–2.5 m (6.2–8.2 ft). The pigeye shark is an apex predator that mostly hunts low in the water column. It has a varied diet, consisting mainly of bony and cartilaginous fishes and also including crustaceans, molluscs, sea snakes, and cetaceans. This species gives birth to live young, with the developing embryos sustained to term via a placental connection to their mother. Litters of three to thirteen pups are born after a gestation period of nine or twelve months. Young sharks spend their first few years of life in sheltered inshore habitats such as bays, where their movements follow tidal and seasonal patterns. The pigeye shark's size and dentition make it potentially dangerous, though it has not been known to attack humans. The shark is infrequently caught in shark nets protecting beaches and by fisheries, which use it for meat and fins. The IUCN presently assesses this species as vulnerable. (Full article...) Sei whale mother and calf The sei whale (/seɪ/ SAY, Norwegian: [sæɪ]; Balaenoptera borealis) is a baleen whale, the third-largest rorqual after the blue whale and the fin whale. 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. Reaching 19.5 m (64 ft) in length and weighing as much as 28 t (28 long tons; 31 short tons), the sei whale consumes an average of 900 kg (2,000 lb) of food every day; its diet consists primarily of copepods, krill, and other zooplankton. It is among the fastest of all cetaceans, and can reach speeds of up to 50 km/h (31 mph) (27 knots) over short distances. The whale's name comes from the Norwegian word for pollock, a fish that appears off the coast of Norway at the same time of the year as the sei whale. (Full article...) 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) Pinnipeds (pronounced /ˈpɪnɪˌpɛdz/), commonly known as seals, are a widely distributed and diverse clade of carnivorous, fin-footed, semiaquatic, mostly marine mammals. They comprise the extant families Odobenidae (whose only living member is the walrus), Otariidae (the eared seals: sea lions and fur seals), and Phocidae (the earless seals, or true seals). There are 34 extant species of pinnipeds, and more than 50 extinct species have been described from fossils. While seals were historically thought to have descended from two ancestral lines, molecular evidence supports them as a monophyletic lineage (descended from one ancestral line). Pinnipeds belong to the order Carnivora; their closest living relatives are musteloids (weasels, raccoons, skunks, and red pandas), having diverged about 50 million years ago. Seals range in size from the 1 m (3 ft 3 in) and 45 kg (99 lb) Baikal seal to the 5 m (16 ft) and 3,200 kg (7,100 lb) southern elephant seal male, which is also the largest member of the order Carnivora. Several species exhibit sexual dimorphism. They have streamlined bodies and four limbs that are modified into flippers. Though not as fast in the water as dolphins, seals are more flexible and agile. Otariids use their front limbs primarily to propel themselves through the water, while phocids and walruses use their hind limbs. Otariids and walruses have hind limbs that can be pulled under the body and used as legs on land. By comparison, terrestrial locomotion by phocids is more cumbersome. Otariids have visible external ears, while phocids and walruses lack these. Pinnipeds have well-developed senses—their eyesight and hearing are adapted for both air and water, and they have an advanced tactile system in their whiskers or vibrissae. Some species are well adapted for diving to great depths. They have a layer of fat, or blubber, under the skin to keep warm in the cold water, and, other than the walrus, all species are covered in fur. (Full article...) Cast of skull at the Natural History Museum of the University of Pisa Livyatan is an extinct genus of macroraptorial sperm whale containing one known species: L. melvillei. The genus name was inspired by the biblical sea monster Leviathan, and the species name by Herman Melville, the author of the famous novel Moby-Dick about a white bull sperm whale. It is mainly known from the Pisco Formation of Peru during the Tortonian stage of the Miocene epoch, about 9.9–8.9 million years ago (mya); however, finds of isolated teeth from other locations such as Chile, Argentina, South Africa, and Australia imply that either it or a close relative survived into the Pliocene, around 5 mya, and was present throughout the Southern Hemisphere. It was a member of a group of macroraptorial sperm whales (or "raptorial sperm whales") and was probably an apex predator, preying on whales, seals, and so forth. Characteristically of raptorial sperm whales, Livyatan had functional, enamel-coated teeth on the upper and lower jaws, as well as several features suitable for hunting large prey. Livyatan's total length has been estimated to be about 13.5–17.5 m (44–57 ft), similar to that of the modern sperm whale (Physeter macrocephalus), making it one of the largest predators known to have existed. The teeth of Livyatan measured 36.2 cm (1.2 ft), and are the largest biting teeth of any known animal, excluding tusks. It is distinguished from the other raptorial sperm whales by the basin on the skull, spanning the length of the snout. The spermaceti organ, contained in that basin is thought to have been used in echolocation and communication, or for ramming prey and other sperm whales. The whale may have interacted with the large extinct shark Megalodon (Otodus megalodon), competing with it for a similar food source. Its extinction was probably caused by a cooling event at the end of the Miocene period causing a reduction in food populations. The geological formation where the whale has been found has also preserved a large assemblage of marine life, such as sharks and marine mammals. (Full article...) Southern right whale breaching Right whales are three species of large baleen whales of the genus Eubalaena: the North Atlantic right whale (E. glacialis), the North Pacific right whale (E. japonica) and the Southern right whale (E. australis). They are classified in the family Balaenidae with the bowhead whale. Right whales have rotund bodies with arching rostrums, V-shaped blowholes and dark gray or black skin. The most distinguishing feature of a right whale is the rough patches of skin on its head, which appear white due to parasitism by whale lice. Right whales are typically 13–17 m (43–56 ft) long and weigh up to 100 short tons (91 t; 89 long tons) or more. All three species are migratory, moving seasonally to feed or give birth. The warm equatorial waters form a barrier that isolates the northern and southern species from one another although the southern species, at least, has been known to cross the equator. In the Northern Hemisphere, right whales tend to avoid open waters and stay close to peninsulas and bays and on continental shelves, as these areas offer greater shelter and an abundance of their preferred foods. In the Southern Hemisphere, right whales feed far offshore in summer, but a large portion of the population occur in near-shore waters in winter. Right whales feed mainly on copepods but also consume krill and pteropods. They may forage the surface, underwater or even the ocean bottom. During courtship, males gather into large groups to compete for a single female, suggesting that sperm competition is an important factor in mating behavior. Gestation tends to last a year, and calves are weaned at eight months old. (Full article...) A humpback whale (Megaptera novaeangliae) Marine mammals are aquatic mammals that rely on the ocean and other marine ecosystems for their existence. They include animals such as seals, whales, manatees, sea otters and polar bears. They are an informal group, unified only by their reliance on marine environments for feeding and survival. Marine mammal adaptation to an aquatic lifestyle varies considerably between species. Both cetaceans and sirenians are fully aquatic and therefore are obligate water dwellers. Seals and sea-lions are semiaquatic; they spend the majority of their time in the water but need to return to land for important activities such as mating, breeding and molting. In contrast, both otters and the polar bear are much less adapted to aquatic living. The diets of marine mammals vary considerably as well; some eat zooplankton, others eat fish, squid, shellfish, or seagrass, and a few eat other mammals. While the number of marine mammals is small compared to those found on land, their roles in various ecosystems are large, especially concerning the maintenance of marine ecosystems, through processes including the regulation of prey populations. This role in maintaining ecosystems makes them of particular concern as 23% of marine mammal species are currently threatened. (Full article...) Fromia monilis Starfish or sea stars are star-shaped echinoderms belonging to the class Asteroidea (/ˌæstəˈrɔɪdiə/). Common usage frequently finds these names being also applied to ophiuroids, which are correctly referred to as brittle stars or basket stars. Starfish are also known as asteroids due to being in the class Asteroidea. About 1,900 species of starfish live on the seabed in all the world's oceans, from warm, tropical zones to frigid, polar regions. They are found from the intertidal zone down to abyssal depths, at 6,000 m (20,000 ft) below the surface. Starfish are marine invertebrates. They typically have a central disc and usually five arms, though some species have a larger number of arms. The aboral or upper surface may be smooth, granular or spiny, and is covered with overlapping plates. Many species are brightly coloured in various shades of red or orange, while others are blue, grey or brown. Starfish have tube feet operated by a hydraulic system and a mouth at the centre of the oral or lower surface. They are opportunistic feeders and are mostly predators on benthic invertebrates. Several species have specialized feeding behaviours including eversion of their stomachs and suspension feeding. They have complex life cycles and can reproduce both sexually and asexually. Most can regenerate damaged parts or lost arms and they can shed arms as a means of defense. The Asteroidea occupy several significant ecological roles. Starfish, such as the ochre sea star (Pisaster ochraceus) and the reef sea star (Stichaster australis), have become widely known as examples of the keystone species concept in ecology. The tropical crown-of-thorns starfish (Acanthaster planci) is a voracious predator of coral throughout the Indo-Pacific region, and the northern Pacific sea star is considered to be one of the world's 100 worst invasive species. (Full article...) Selected article - Zooplankton sample including several species of copepods (1–5), gastropod larva (6) doliolids (7), fish eggs (8), and decapod larva (9) Zooplankton are the animal component of the planktonic community ("zoo" comes from the Greek word for animal). Plankton are aquatic organisms that are unable to swim effectively against currents. Consequently, they drift or are carried along by currents in the ocean, or by currents in seas, lakes or rivers. Zooplankton can be contrasted with phytoplankton, which are the plant component of the plankton community ("phyto" comes from the Greek word for plant). Zooplankton are heterotrophic (other-feeding), whereas phytoplankton are autotrophic (self-feeding). In other words, zooplankton cannot manufacture their own food. Rather, they must eat other plants or animals instead. In particular, they eat phytoplankton, which are generally smaller than zooplankton. Most zooplankton are microscopic but some (such as jellyfish) are macroscopic, meaning they can be seen with the naked eye. (Full article...) List of selected articles Jacques Cousteau Ed Ricketts John Murray (oceanographer) George Albert Boulenger Anton Dohrn Nicholas Miklouho-Maclay Edward Drinker Cope Amphiprioninae Giant squid Antarctic krill Shrimp Pelagic zone Marine microorganisms Marine viruses Marine prokaryotes Marine fungi Marine invertebrates Sponge Ctenophora Cnidaria Marine worm Arthropod Cephalopod Evolution of cephalopods Evolution of molluscs Mollusca Arthropod Shark Panarthropoda Evolution of brachiopods Echinoderm Saltwater fish Saltwater crocodile Hemichordate Marine vertebrate Actinopterygii Pteraspidomorphi Hammerhead shark Winghead shark Chondrichthyes Osteichthyes Marine reptile Seabird Ocean Marine primary production Mackerel Tuna Barracuda Algae Microalgae Phytoplankton Plankton Octocorallia Marine food web Marine biogeochemical cycles Human impact on marine life History of marine biology Marine habitats Coral reef Biological oceanography Microplastics Marine pollution Aquatic plant Ice algae Whale fall Hydrozoa Marine life images - Seep 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) Salmon with fungal disease (from Marine fungi) "A variety of marine worms": plate from Das Meer by M.J. Schleiden (1804–1881) (from Marine invertebrates) Kelp forests provide habitat for many marine organisms (from Marine habitats) This 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 habitats) Fishing down the food web (from Marine food web) Coral reefs have a great amount of biodiversity. (from Marine conservation) Reconstruction of Otavia antiqua, possibly the first animal about 760 million years ago  (from Marine invertebrates) Coastlines can be volatile habitats (from Marine habitats) Cycling 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) 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) Halobacteria in salt evaporation ponds coloured purple by bacteriorhodopsin (from Marine prokaryotes) Kimberella, an early mollusc important for understanding the Cambrian explosion. Invertebrates are grouped into different phyla (body plans). (from Marine invertebrates) Bryozoa, from Ernst Haeckel's Kunstformen der Natur, 1904 (from Marine invertebrates) Sponges have no nervous, digestive or circulatory system (from Marine invertebrates)   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 habitats) The extinct Pteraspidomorphi, ancestral to jawed vertebrates (from Marine vertebrate) In 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 habitats) Topological positions versus mobility  Error in Template:Align: the alignment setting "(A) bottom-up groups (sessile and drifters)" is invalid.Error in Template:Align: the alignment setting "(B) groups at the top of the food web" is invalid. ___________________________________________________________________ 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) Land runoff, pouring into the sea, can contain nutrients (from Marine habitats) A 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) Halfbeak as larvae are one of the organisms adapted to the unique properties of the microlayer (from Marine habitats) Ocean 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) 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) Sea otter, classic keystone species which controls sea urchin numbers (from Marine vertebrate) 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) The 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 habitats) Sea 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) Phylogenetic 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) Prochlorococcus, an influential bacterium which produces much of the world's oxygen (from Marine food web) 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 food web) Scale diagram of the layers of the pelagic zone (from Marine habitats) Pelagibacter 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) Lichen covered rocks (from Marine fungi) Earth's magnetic field (from Marine prokaryotes) Bloom of the filamentous cyanobacteria Trichodesmium (from Marine prokaryotes) Schematic 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) Two Nanoarchaeum equitans cells with its larger host Ignicoccus (from Marine prokaryotes) Role of micronekton in pelagic food webs Oceanic 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) 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 food web) This timeline contains clickable links Common-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) Tidepools on rocky shores make turbulent habitats for many forms of marine life (from Marine habitats) Sandy shores provide shifting homes to many species (from Marine habitats) The shore of the Pacific Ocean in San Francisco, California (from Marine conservation) Diagram above contains clickable links 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) Hagfish are the only known living animals with a skull but no vertebral column. (from Marine vertebrate) Morphological diversity of fungi collected from a marine sponge species, Ircinia variabilis (from Marine fungi) A sleeping monk seal on the sandy beach with the ocean behind it (from Marine conservation) Eukaryote versus prokaryote (from Marine prokaryotes) 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) Antarctic 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) Mudflats become temporary habitats for migrating birds (from Marine habitats) A 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) Deep pelagic web An 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) Scanning 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) Estuaries 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 habitats) Mangroves provide nurseries for fish (from Marine habitats) Microplastics found in sediments on the seafloor (from Marine habitats) On 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) Generalized or hypothetical ancestral mollusc (from Marine invertebrates) Classic food web for grey seals in the Baltic Sea containing several typical marine food chains (from Marine food web) A 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) The chloroplasts of glaucophytes have a peptidoglycan layer, evidence suggesting their endosymbiotic origin from cyanobacteria. (from Marine prokaryotes) The 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) Cnidarians 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) Diatoms (from Marine food web) Sea 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) Fan mussel in a Mediterranean seagrass meadow (from Marine habitats) Food 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) Archaea 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) Phylogenetic and symbiogenetic tree of living organisms, showing a view of the origins of eukaryotes and prokaryotes (from Marine prokaryotes) Mudflat pollution (from Marine habitats) Ocean or marine biomass, in a reversal of terrestrial biomass, can increase at higher trophic levels. (from Marine food web) Predator fish sizing up schooling forage fish (from Marine food web) Phytoplankton (from Marine food web) Humpback whale straining krill (from Marine food web) Elevation-area graph showing the proportion of land area at given heights and the proportion of ocean area at given depths (from Marine habitats) Opabinia, an extinct stem group arthropod appeared in the Middle Cambrian (from Marine invertebrates) The remains from the Exxon Valdez oil spill after the second treatment by oil spill workers in Alaska (from Marine conservation) Export processes in the Ocean from remote sensing (from Marine prokaryotes) Reconstruction 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) Giant kelp is a foundation species for many kelp forests. (from Marine food web) Cryptic 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) Pennate 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) Dinoflagellate (from Marine food web) The 49th plate from Ernst Haeckel's Kunstformen der Natur, 1904, showing various sea anemones classified as Actiniae, in the Cnidaria phylum (from Marine invertebrates) Driftwood (from Marine fungi) Pennate 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) Cyanobacteria blooms can contain lethal cyanotoxins (from Marine prokaryotes) Bacterial flagellum rotated by a molecular motor at its base (from Marine prokaryotes) Biomass pyramids Compared to terrestrial biomass pyramids, aquatic pyramids are generally inverted at the base (from Marine food web) Lampreys are often parasitic and have a toothed, funnel-like sucking mouth (from Marine vertebrate) The umbrella mouth gulper eel can swallow a fish much larger than itself (from Marine habitats) The 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) Some lobe-finned fishes, like the extinct Tiktaalik, developed limb-like fins that could take them onto land (from Marine vertebrate) 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) 640 µm microplastic found in the deep sea amphipod Eurythenes plasticus (from Marine habitats) The range of sizes shown by prokaryotes (bacteria and archaea) and viruses relative to those of other organisms and biomolecules (from Marine prokaryotes) Jellyfish are easy to capture and digest and may be more important as food sources than was previously thought. (from Marine food web) Ernst 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) Mature forests have a lot of biomass invested in secondary growth which has low productivity (from Marine food web) The oligotrich ciliate has been characterised as the most important herbivore in the ocean (from Marine food web) Ocean particulate organic matter (POM) as imaged by a satellite in 2011 (from Marine food web) Only 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. Conceptual diagram of faunal community structure and food-web patterns along fluid-flux gradients within Guaymas seep and vent ecosystems. (from Marine food web) Some 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 habitats) Anthropogenic stressors to marine species threatened with extinction (from Marine food web) Waves and currents shape the intertidal shoreline, eroding the softer rocks and transporting and grading loose particles into shingles, sand or mud (from Marine habitats) Phylogenetic and symbiogenetic tree of living organisms, showing a view of the origins of eukaryotes and prokaryotes (from Marine fungi) Polar bears on the sea ice of the Arctic Ocean, near the North Pole (from Marine conservation) Vibrio vulnificus, a virulent bacterium found in estuaries and along coastal areas (from Marine prokaryotes) Arrow worms are predatory components of plankton worldwide. (from Marine invertebrates) Starfish larvae are bilaterally symmetric, whereas the adults have fivefold symmetry (from Marine invertebrates) Dickinsonia may be the earliest animal. They appear in the fossil record 571 million to 541 million years ago. (from Marine invertebrates) 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) Chytrid 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) General images - The following are images from various marine life-related articles on Wikipedia. In the fourth century BC, Aristotle gave accurate descriptions of the embryological development of the hound shark Mustelus mustelus. (from History of marine biology) Estuaries (from Marine ecosystem) Sea 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) Kelp forest (from Marine ecosystem) The extinct Pteraspidomorphi, ancestral to jawed vertebrates (from Marine vertebrate) Salt marshes (from Marine ecosystem) Seagrass meadow (from Marine ecosystem) Ecosystem 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) Hagfish are the only known living animals with a skull but no vertebral column. (from Marine vertebrate) Coral reefs form complex marine ecosystems with tremendous biodiversity (from Marine ecosystem) Lampreys are often parasitic and have a toothed, funnel-like sucking mouth (from Marine vertebrate) A science ROV being retrieved by an oceanographic research vessel. (from History of marine biology) Some lobe-finned fishes, like the extinct Tiktaalik, developed limb-like fins that could take them onto land (from Marine vertebrate) Mangrove forests (from Marine ecosystem) Sea otter, classic keystone species which controls sea urchin numbers (from Marine vertebrate) Coral reef (from Marine ecosystem) The voyage of the Beagle (from History of marine biology) Lagoon (from Marine ecosystem) Intertidal zones (from Marine ecosystem) Model of a Greek boat (from History of marine biology) Drivers of change in marine ecosystems (from Marine ecosystem) HMS Challenger during its pioneer expedition of 1872–76 (from History of marine biology) Global distribution of coral, mangrove, and seagrass diversity (from Marine ecosystem) Did you know (auto-generated) ... that the coral reefs of Tuvalu include the Funafuti Conservation Area, which encompasses 20 per cent of the reef area of Funafuti atoll? ... that Choctaw was one of only three semi-whaleback ships ever built? ... that in the lead-up to the Second World War, the British government stockpiled more than 100,000 tons of whale oil? ... that the South Asian river dolphin is nearly blind and relies on echolocation for navigation? ... that Alexis Sharkey's last Instagram post before her murder documented her travels to Tulum, Mexico? ... that Concurrent Computer Corporation was consumed in a "minnow-swallows-the-whale" merger during the junk bonds era, but unusually, kept its name, CEO, and headquarters? More Did you know - ... Shark skin is so rough that in the past it was used to make a type of sandpaper, called shagreen. ... 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. ... the Beaked whales (genus Ziphidae) contain over twenty species of small whales, and are the least known of all cetaceans. ... The Horseshoe crab has blue, copper based blood. ... all cetaceans have a blubber layer — a layer of fat under the skin. In most dolphins, this layer is about one quarter to one third of the total body weight, but in southern right whales nearly half of its weight (up to 50 tons) will be blubber. ... the Sperm Whale, at 18 metres long, is the largest toothed animal to have ever lived. Related portals Topics List articles List of aquaria List of AZA member zoos and aquariums List of botanists List of cetaceans List of dolphin species List of ecologists List of ecoregions List of mangrove ecoregions List of marine aquarium fish species List of porpoise species Ramsar list of wetlands of international importance List of Ramsar sites in Scotland List of Ramsar Wetland sites in Pakistan List of sharks List of Ramsar wetlands of Thailand List of regional bird lists List of regional mammals lists United States Fish and Wildlife Service list of endangered species List of whale species List of zoos Categories Select [►] to view subcategories Aquatic organisms Aquatic life in culture Amphibious organisms Aquatic animals Brackish water organisms Fictional aquatic creatures Freshwater organisms Aquatic fungi Marine microorganisms Marine organisms Mythological aquatic creatures Organisms living on hydrothermal vents Plankton Aquatic plants Semiaquatic organisms Marine biology Biological oceanography Marine biologists Marine botany Cetology Conchology Films about marine biology Fisheries science Marine biological stations Marine organisms Planktology 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 Selected image Photo credit: OAR/National Undersea Research Program (NURP) The French angelfish, Pomacanthus paru, is a member of the Marine angelfish family. Marine angelfishes are a type of perciform fish of the family Pomacanthidae. Found on shallow reefs in the tropical Atlantic, Indian, and mostly western Pacific Ocean, the family contains seven genera and approximately 86 species. They should not be confused with the freshwater angelfish, tropical cichlids of the Amazon River basin. More on the french angelfish See also For additional lists of marine life-related featured articles and good articles see: WikiProject Cetaceans § Featured and Good Content Portal:Fish/Recognized content Portal:Sharks/Selected articles Associated Wikimedia The following Wikimedia Foundation sister projects provide more on this subject: Commons Free media repository Wikibooks Free textbooks and manuals Wikidata Free knowledge base Wikinews Free-content news Wikiquote Collection of quotations Wikisource Free-content library Wikiversity Free learning tools Wiktionary Dictionary and thesaurus WikiProjects The Wikiproject associated with this portal is the Marine Life WikiProject Other WikiProjects include: Biology Oceans Tree of Life Birds Mammals Cetaceans Fishes Sharks Fisheries and fishing Amphibians and Reptiles Plants Cephalopods Gastropods Monotremes and Marsupials Tasks Have a look at the Marine life WikiProject and sign up. 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