Portal:Marine life

A male whale shark at the Georgia Aquarium.

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.

Image 1

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...)
Image 2

Gold-mouth sea squirt (Polycarpa aurata)

A tunicate is a marine invertebrate animal, a member of the subphylum Tunicata (/ˌtjuːnɪˈkeɪtə/ TEW-nih-KAY-tə). It is part of the Chordata, a phylum which includes all animals with dorsal nerve cords and notochords (including vertebrates). The subphylum was at one time called Urochordata, and the term urochordates is still sometimes used for these animals. They are the only chordates that have lost their myomeric segmentation, with the possible exception of the 'seriation of the gill slits'. However, doliolids still display segmentation of the muscle bands.

Some tunicates live as solitary individuals, but others replicate by budding and become colonies, each unit being known as a zooid. They are marine filter feeders with a water-filled, sac-like body structure and two tubular openings, known as siphons, through which they draw in and expel water. During their respiration and feeding, they take in water through the incurrent (or inhalant) siphon and expel the filtered water through the excurrent (or exhalant) siphon. Adult ascidian tunicates are sessile, immobile and permanently attached to rocks or other hard surfaces on the ocean floor. Thaliaceans (pyrosomes, doliolids, and salps) and larvaceans on the other hand, swim in the pelagic zone of the sea as adults. (Full article...)
Image 3

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 4

Malacostraca (from Neo-Latin; from Ancient Greek μαλακός (malakós) 'soft', and όστρακον (óstrakon) 'shell') is the second largest of the six classes of crustaceans just behind hexapods, containing about 40,000 living species, divided among 16 orders. Its members, the malacostracans, display a great diversity of body forms and include crabs, lobsters, crayfish, shrimp, krill, prawns, woodlice, amphipods, mantis shrimp, tongue-eating lice and many other less familiar animals. They are abundant in all marine environments and have colonised freshwater and terrestrial habitats. They are segmented animals, united by a common body plan comprising 20 body segments (rarely 21), and divided into a head, thorax, and abdomen. (Full article...)
Image 5

A stove-pipe sponge

Sponges, the members of the phylum Porifera (/pəˈrɪfərə/; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through them, consisting of jelly-like mesohyl sandwiched between two thin layers of cells.

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. 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 6

Crab

Crustaceans belong to the subphylum Crustacea (/krəˈsteɪʃə/), and form a large, diverse group of arthropods including decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, opossum shrimps, amphipods and mantis shrimp. The crustacean group can be treated as a subphylum under the clade Mandibulata. It is now well accepted that the hexapods (insects and entognathans) emerged deep in the Crustacean group, with the completed group referred to as Pancrustacea. The three classes Cephalocarida, Branchiopoda and Remipedia are more closely related to the hexapods than they are to any of the other crustaceans (oligostracans and multicrustaceans).

The 67,000 described species range in size from Stygotantulus stocki at 0.1 mm (0.004 in), to the Japanese spider crab with a leg span of up to 3.8 m (12.5 ft) and a mass of 20 kg (44 lb). Like other arthropods, crustaceans have an exoskeleton, which they moult to grow. They are distinguished from other groups of arthropods, such as insects, myriapods and chelicerates, by the possession of biramous (two-parted) limbs, and by their larval forms, such as the nauplius stage of branchiopods and copepods. (Full article...)
Image 7

Southern right whale

Whales are a widely distributed and diverse group of fully aquatic placental marine mammals. As an informal and colloquial grouping, they correspond to large members of the infraorder Cetacea, i.e. all cetaceans apart from dolphins and porpoises. Dolphins and porpoises may be considered whales from a formal, cladistic perspective. Whales, dolphins and porpoises belong to the order Cetartiodactyla, which consists of even-toed ungulates. Their closest non-cetacean living relatives are the hippopotamuses, from which they and other cetaceans diverged about 54 million years ago. The two parvorders of whales, baleen whales (Mysticeti) and toothed whales (Odontoceti), are thought to have had their last common ancestor around 34 million years ago. Mysticetes include four extant (living) families: Balaenopteridae (the rorquals), Balaenidae (right whales), Cetotheriidae (the pygmy right whale), and Eschrichtiidae (the grey whale). Odontocetes include the Monodontidae (belugas and narwhals), Physeteridae (the sperm whale), Kogiidae (the dwarf and pygmy sperm whale), and Ziphiidae (the beaked whales), as well as the six families of dolphins and porpoises which are not considered whales in the informal sense.

Whales are fully aquatic, open-ocean animals: they can feed, mate, give birth, suckle and raise their young at sea. Whales range in size from the 2.6 metres (8.5 ft) and 135 kilograms (298 lb) dwarf sperm whale to the 29.9 metres (98 ft) and 190 tonnes (210 short tons) blue whale, which is the largest known animal that has ever lived. The sperm whale is the largest toothed predator on Earth. Several whale species exhibit sexual dimorphism, in that the females are larger than males. (Full article...)
Image 8

Female individual surrounded by pilot fish in the Red Sea

The oceanic whitetip shark (Carcharhinus longimanus) is a large pelagic requiem shark inhabiting tropical and warm temperate seas. It has a stocky body with long, white-tipped, rounded fins. The species is typically solitary, though they may gather in large numbers at food concentrations. Bony fish and cephalopods are the main components of its diet and females give live birth.

Though slow-moving, it is opportunistic and aggressive, and is reputed to be dangerous to shipwreck survivors. The IUCN Red List considers the species to be critically endangered. Recent studies show steeply declining populations as they are harvested for their fins and meat. As with other shark species, the whitetip faces mounting fishing pressure throughout its range. (Full article...)
Image 9
Steller's sea ape is a purported marine mammal, observed by German zoologist Georg Steller on August 10, 1741, around the Shumagin Islands in Alaska. The animal was described as being around 1.5 m (5 feet) long; with a dog-like head; long drooping whiskers; an elongated but robust body; thick fur coat; no limbs; and tail fins much like a shark. He described the creature as being playful and inquisitive like a monkey. After observing it for two hours, he attempted to shoot and collect the creature, but missed, and the creature swam away.

There have been four attempts to scientifically classify the creature, described as Simia marina, Siren cynocephala, Trichechus hydropithecus, and Manatus simia. Most likely, Steller simply misidentified a northern fur seal. (Full article...)
Image 10

Bottlenose dolphin surfing in the wake of a boat

Bottlenose dolphins are aquatic mammals in the genus Tursiops. They are common, cosmopolitan members of the family Delphinidae, the family of oceanic dolphins. Molecular studies show the genus definitively contains three species: the common bottlenose dolphin (Tursiops truncatus), the Indo-Pacific bottlenose dolphin (Tursiops aduncus), and Tamanend's bottlenose dolphin (Tursiops erebennus). Others, like the Burrunan dolphin (Tursiops (aduncus) australis), may be alternately considered their own species or be subspecies of T. aduncus. Bottlenose dolphins inhabit warm and temperate seas worldwide, being found everywhere except for the Arctic and Antarctic Circle regions. Their name derives from the Latin tursio (dolphin) and truncatus for their characteristic truncated teeth.

Numerous investigations of bottlenose dolphin intelligence have been conducted, examining mimicry, use of artificial language, object categorization, and self-recognition. They can use tools (sponging; using marine sponges to forage for food sources they normally could not access) and transmit cultural knowledge from generation to generation, and their considerable intelligence has driven interaction with humans. Bottlenose dolphins gained popularity from aquarium shows and television programs such as Flipper. They have also been trained by militaries to locate sea mines or detect and mark enemy divers. In some areas, they cooperate with local fishermen by driving fish into their nets and eating the fish that escape. Some encounters with humans are harmful to the dolphins: people hunt them for food, and dolphins are killed inadvertently as a bycatch of tuna fishing and by getting caught in crab traps. (Full article...)

Selected article -

Reptiles that live in the sea:
• Saltwater crocodile (top left)
• Sea turtle (top right)
• Marine iguana (bottom left)
• Sea snake (bottom right)

Marine reptiles are reptiles which have become secondarily adapted for an aquatic or semiaquatic life in a marine environment.

The earliest marine reptile was Mesosaurus (not to be confused with Mosasaurus), which arose in the Permian period of the Paleozoic era. During the Mesozoic era, many groups of reptiles became adapted to life in the seas, including such familiar clades as the ichthyosaurs, plesiosaurs (these two orders were once thought united in the group "Enaliosauria", a classification now cladistically obsolete), mosasaurs, nothosaurs, placodonts, sea turtles, thalattosaurs and thalattosuchians. Most marine reptile groups became extinct at the end of the Cretaceous period, but some still existed during the Cenozoic, most importantly the sea turtles. Other Cenozoic marine reptiles included the bothremydids, palaeophiid snakes, a few choristoderes such as Simoedosaurus and dyrosaurid crocodylomorphs. Various types of marine gavialid crocodilians remained widespread as recently as the Late Miocene. (Full article...)

List of selected articles

Marine life images -

Image 1The shore of the Pacific Ocean in San Francisco, California (from Marine conservation)
Image 2Cryptic 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 3Phylogenetic 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 4Coral reefs have a great amount of biodiversity. (from Marine conservation)
Image 5Kelp forests provide habitat for many marine organisms (from Marine habitat)
Image 6The umbrella mouth gulper eel can swallow a fish much larger than itself (from Marine habitat)
Image 7Classic food web for grey seals in the Baltic Sea containing several typical marine food chains (from Marine food web)
Image 8Cnidarians 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 9Mudflats become temporary habitats for migrating birds (from Marine habitat)
Image 10Some 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 11Lampreys are often parasitic and have a toothed, funnel-like sucking mouth (from Marine vertebrate)
Image 12
Eukaryote versus prokaryote
(from Marine prokaryotes)
Image 13
Coastlines can be volatile habitats
(from Marine habitat)
Image 14Cyanobacteria blooms can contain lethal cyanotoxins (from Marine prokaryotes)
Image 15On 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 16Predator fish sizing up schooling forage fish (from Marine food web)
Image 17Pennate 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 18
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 19Jellyfish are easy to capture and digest and may be more important as food sources than was previously thought. (from Marine food web)
Image 20Sea 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 21Anthropogenic stressors to marine species threatened with extinction (from Marine food web)
Image 22
Generalized or hypothetical ancestral mollusc
(from Marine invertebrates)
Image 23Only 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 24The remains from the Exxon Valdez oil spill after the second treatment by oil spill workers in Alaska (from Marine conservation)
Image 25Pennate 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 26The range of sizes shown by prokaryotes (bacteria and archaea) and viruses relative to those of other organisms and biomolecules (from Marine prokaryotes)
Image 27This timeline contains clickable links
Image 28The 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 29Morphological diversity of fungi collected from a marine sponge species, Ircinia variabilis (from Marine fungi)
Image 30Elevation-area graph showing the proportion of land area at given heights and the proportion of ocean area at given depths (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 32Hagfish are the only known living animals with a skull but no vertebral column. (from Marine vertebrate)
Image 33The 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 34Halobacteria in salt evaporation ponds coloured purple by bacteriorhodopsin (from Marine prokaryotes)
Image 35Giant kelp is a foundation species for many kelp forests. (from Marine food web)
Image 36640 µm microplastic found in the deep sea amphipod Eurythenes plasticus (from Marine habitat)
Image 37
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 38Ernst 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 39Polar bears on the sea ice of the Arctic Ocean, near the North Pole (from Marine conservation)
Image 40A sleeping monk seal on the sandy beach with the ocean behind it (from Marine conservation)
Image 41Seep 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 42Diagram above contains clickable links
Image 43A 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 44 Opabinia, an extinct stem group arthropod appeared in the Middle Cambrian (from Marine invertebrates)
Image 45Humpback whale straining krill (from Marine food web)
Image 46 Bloom of the filamentous cyanobacteria Trichodesmium (from Marine prokaryotes)
Image 47Reconstruction 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 48Microplastics found in sediments on the seafloor (from Marine habitat)
Image 49
Export processes in the Ocean from remote sensing
(from Marine prokaryotes)
Image 50Some lobe-finned fishes, like the extinct Tiktaalik, developed limb-like fins that could take them onto land (from Marine vertebrate)
Image 51The extinct Pteraspidomorphi, ancestral to jawed vertebrates (from Marine vertebrate)
Image 52Phylogenetic and symbiogenetic tree of living organisms, showing a view of the origins of eukaryotes and prokaryotes (from Marine prokaryotes)
Image 53Sponges have no nervous, digestive or circulatory system (from Marine invertebrates)
Image 54
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 55Mature forests have a lot of biomass invested in secondary growth which has low productivity (from Marine food web)
Image 56In 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 57Mangroves provide nurseries for fish (from Marine habitat)
Image 58Vibrio vulnificus, a virulent bacterium found in estuaries and along coastal areas (from Marine prokaryotes)
Image 59The 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 60Common-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 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 62Archaea 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 63Pelagibacter 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 64Biomass pyramids. Compared to terrestrial biomass pyramids, aquatic pyramids are generally inverted at the base. (from Marine food web)
Image 65Salmon with fungal disease (from Marine fungi)
Image 66Chytrid 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 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 68Earth's magnetic field (from Marine prokaryotes)
Image 69Bacterial flagellum rotated by a molecular motor at its base (from Marine prokaryotes)
Image 70This 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 71Oceanic 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 72Food 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 73
Mudflat pollution
(from Marine habitat)
Image 74Land runoff, pouring into the sea, can contain nutrients (from Marine habitat)
Image 75
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 76Fishing down the food web (from Marine food web)
Image 77
Lichen covered rocks
(from Marine fungi)
Image 78Topological 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 79Dinoflagellate (from Marine food web)
Image 80Sandy shores provide shifting homes to many species (from Marine habitat)
Image 81"A variety of marine worms": plate from Das Meer by M.J. Schleiden (1804–1881) (from Marine invertebrates)
Image 82Scale diagram of the layers of the pelagic zone (from Marine habitat)
Image 83Conceptual diagram of faunal community structure and food-web patterns along fluid-flux gradients within Guaymas seep and vent ecosystems. (from Marine food web)
Image 84Ocean particulate organic matter (POM) as imaged by a satellite in 2011 (from Marine food web)
Image 85Schematic 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 86
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 87Sea otter, classic keystone species which controls sea urchin numbers (from Marine vertebrate)
Image 88Diatoms (from Marine food web)
Image 89An 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 90The chloroplasts of glaucophytes have a peptidoglycan layer, evidence suggesting their endosymbiotic origin from cyanobacteria. (from Marine prokaryotes)
Image 91Estuaries 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 92Phylogenetic and symbiogenetic tree of living organisms, showing a view of the origins of eukaryotes and prokaryotes (from Marine fungi)
Image 93Cycling 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 94
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 95Two Nanoarchaeum equitans cells with its larger host Ignicoccus (from Marine prokaryotes)
Image 96 Kimberella, an early mollusc important for understanding the Cambrian explosion. Invertebrates are grouped into different phyla (body plans). (from Marine invertebrates)
Image 97Marine Species Changes in Latitude and Depth in three different ocean regions(1973-2019) (from Marine food web)
Image 98Reconstruction of Otavia antiqua, possibly the first animal about 760 million years ago (from Marine invertebrates)
Image 99Arrow worms are predatory components of plankton worldwide. (from Marine invertebrates)
Image 100A 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 101
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 102Phytoplankton (from Marine food web)
Image 103 Dickinsonia may be the earliest animal. They appear in the fossil record 571 million to 541 million years ago. (from Marine invertebrates)
Image 104Tidepools on rocky shores make turbulent habitats for many forms of marine life (from Marine habitat)
Image 105Fan mussel in a Mediterranean seagrass meadow (from Marine habitat)
Image 106Halfbeak as larvae are one of the organisms adapted to the unique properties of the microlayer (from Marine habitat)
Image 107
Driftwood
(from Marine fungi)
Image 108The oligotrich ciliate has been characterised as the most important herbivore in the ocean (from Marine food web)
Image 109Waves 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 110The 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 111Ocean or marine biomass, in a reversal of terrestrial biomass, can increase at higher trophic levels. (from Marine food web)
Image 112Prochlorococcus, an influential bacterium which produces much of the world's oxygen (from Marine food web)
Image 113Sea 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 114Bryozoa, from Ernst Haeckel's Kunstformen der Natur, 1904 (from Marine invertebrates)
Image 115Starfish larvae are bilaterally symmetric, whereas the adults have fivefold symmetry (from Marine invertebrates)
Image 116
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 117A 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)

General images -

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

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

Did you know (auto-generated)

... that the three dolphins on the coat of arms of Anguilla represent "unity, strength and endurance", which is also the motto of the territory?
... that one can swim with humpback whales in the Niue Nukutuluea Multiple-Use Marine Park?
... that "the Hurricane Shark is real"?
... that Hixxy and Sharkey created a schism in the UK rave music scene in 1995?
... that Timo Meier became the first player in San Jose Sharks franchise history to score five goals in one game when he was 25?
... that coral reef restoration can include growing fragments of coral in nurseries, attached to frames or lines?

More Did you know -

... The ear bone called the hammer (malleus) in cetaceans is fused to the walls of the bone cavity where the ear bones are, making hearing in air nearly impossible. Instead sound is transmitted through their jaws and skull bones.
... that the Southern Right Whale got its name because it was the ‘right’ whale to kill? Because they swim slowly, close to the shore and float when killed, the whalers thought them the right whales to kill!
... whales and dolphins don’t sleep in the way humans do. Although we don’t know how they sleep, some scientists believe they sleep with half the brain asleep and half the brain awake, keeping them aware of danger.
... newborn cetacean calves ‘suckle’ three to four times each hour and will suckle from their mothers for six months or more.
... Qi Qi was the name of one of several captive Baijis held at the Wuhan Institute in China in an attempt to rescue the species.
... Epaulette sharks are often found in rock pools. They can move from one pool to another across dry land, by dragging themselves with their strong pectoral fins.

Related portals

Topics

List articles

Selected image

Photo credit: Mdf

The Double-crested Cormorant (Phalacrocorax auritus) is a North American member of the cormorant family of seabirds. Its name is derived from the Greek words phalakros (bald) and kora (raven), and the Latin auritus (eared). Folk names of this bird include Crow-duck, Farallon Cormorant, Florida Cormorant, lawyer, shag, and Taunton turkey.

More on the Double-crested Cormorant

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.

Here are some tasks you can do, as organized by The Marine life Wikiproject:

Collaboration of the week: Marine life article assessment
Other: See the projects page
Images: Upload any non-copyrighted marine life images to Wikimedia Commons
Featured Articles/Good Articles:
Other: Add {{Portal|Marine life}} to related articles

Discover Wikipedia using portals

List of all portals

List of all portals
The arts portal

The arts portal
Biography portal

Biography portal
Current events portal

Current events portal
Geography portal

Geography portal
History portal

History portal
Mathematics portal

Mathematics portal
Science portal

Science portal
Society portal

Society portal
Technology portal

Technology portal
Random portal

Random portal
WikiProject Portals

WikiProject Portals

This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.

Marine ecosystems
Marine	f-ratio Iron fertilization Iron Hypothesis Large marine ecosystem Marine biology Marine ecosystem Marine snow Ocean chemistry Ocean fertilization Ocean turbidity Oceanic physical-biological process Photophore Thorson's rule Upwelling Whale fall more ...
Marine life forms	Census of Marine Life Coastal fish Coral reef fish Deep sea communities Deep sea creature Deep sea fish Deep-water coral Demersal fish Marine bacteriophage Marine invertebrates Marine larval ecology Marine mammal Marine reptile Marine vertebrate Paradox of the plankton Pelagic fish Seabird Seashore wildlife Wild fisheries
Marine habitats	Bay mud Black smokers Coastal biogeomorphology Cold seeps Coral reefs Davidson Seamount Estuaries Hydrothermal vents Intertidal ecology Intertidal wetlands Kelp forests Lagoons Mangroves Marine biomes Marine habitats Mudflats Rocky shores Salt marshes Seagrass meadows Sponge reefs Tide pools
Issues	Ecological values of mangrove Fisheries and climate change HERMIONE Marine conservation Marine conservation activism Marine pollution Marine protected area